WorldWideScience

Sample records for actinium bromides

  1. Extraction of actinium with di-(2-ethylhexyl)phosphoric acid from hydrochloric and nitric acid solutions

    The extraction of actinium with HDEHP from Cl- and NO3- systems has been investigated. It was found that extraction of actinium from HCl solutions is much better than from HNO3 solutions. Stability constants of actinium complexes Ac(X-)+2 with Cl- and NO3- ligands were determined. Our results show that the actinium formed less stable complexes with Cl- than with NO3- ligands. 5 refs., 3 figs., 1 tab. (author)

  2. The sorption of polonium, actinium and protactinium onto geological materials

    This paper describes a combined experimental and modeling program of generic sorption studies to increase confidence in the performance assessment for a potential high-level radioactive waste repository in Japan. The sorption of polonium, actinium and protactinium onto geological materials has been investigated. Sorption of these radioelements onto bentonite, tuff and granodiorite from equilibrated de-ionized water was studied under reducing conditions at room temperature. In addition, the sorption of actinium and protactinium was investigated at 60 C. Thermodynamic chemical modeling was carried out to aid interpretation of the results

  3. Separation of Actinium 227 from the uranium minerals

    The purpose of this work was to separate Actinium 227, whose content is 18%, from the mineral carnotite found in Gomez Chihuahua mountain range in Mexico. The mineral before processing is is pre-concentrated and passed, first through anionic exchange resins, later the eluate obtained is passed through cationic resins. The resins were 20-50 MESH QOWEX and 100-200 MESH 50 X 8-20 in some cased 200-400 MESH AG 50W-X8, 1X8 in other cases. The eluates from the ionic exchange were electrodeposited on stainless steel polished disc cathode and platinum electrode as anode; under a current ODF 10mA for 2.5 to 5 hours and of 100mA for .5 of an hour. it was possible to identify the Actinium 227 by means of its descendents, TH-227 and RA-223, through alpha spectroscopy. Due to the radiochemical purity which the electro deposits were obtained the Actinium 227 was low and was not quantitatively determined. A large majority of the members of the natural radioactive series 3 were identified and even alpha energies reported in the literature with very low percentages of non-identified emissions were observed. We conclude that a more precise study is needed concerning ionic exchange and electrodeposit to obtain an Actinium 227 of radiochemical purity. (Author)

  4. Spectroscopic and computational investigation of actinium coordination chemistry.

    Ferrier, Maryline G; Batista, Enrique R; Berg, John M; Birnbaum, Eva R; Cross, Justin N; Engle, Jonathan W; La Pierre, Henry S; Kozimor, Stosh A; Lezama Pacheco, Juan S; Stein, Benjamin W; Stieber, S Chantal E; Wilson, Justin J

    2016-01-01

    Actinium-225 is a promising isotope for targeted-α therapy. Unfortunately, progress in developing chelators for medicinal applications has been hindered by a limited understanding of actinium chemistry. This knowledge gap is primarily associated with handling actinium, as it is highly radioactive and in short supply. Hence, Ac(III) reactivity is often inferred from the lanthanides and minor actinides (that is, Am, Cm), with limited success. Here we overcome these challenges and characterize actinium in HCl solutions using X-ray absorption spectroscopy and molecular dynamics density functional theory. The Ac-Cl and Ac-OH2O distances are measured to be 2.95(3) and 2.59(3) Å, respectively. The X-ray absorption spectroscopy comparisons between Ac(III) and Am(III) in HCl solutions indicate Ac(III) coordinates more inner-sphere Cl(1-) ligands (3.2±1.1) than Am(III) (0.8±0.3). These results imply diverse reactivity for the +3 actinides and highlight the unexpected and unique Ac(III) chemical behaviour. PMID:27531582

  5. Discovery of the actinium, thorium, protactinium, and uranium isotopes

    Fry, C; Thoennessen, M

    2012-01-01

    Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  6. Production of high-purity radium-223 from legacy actinium-beryllium neutron sources.

    Soderquist, Chuck Z; McNamara, Bruce K; Fisher, Darrell R

    2012-07-01

    Radium-223 is a short-lived alpha-particle-emitting radionuclide with potential applications in cancer treatment. Research to develop new radiopharmaceuticals employing (223)Ra has been hindered by poor availability due to the small quantities of parent actinium-227 available world-wide. The purpose of this study was to develop innovative and cost-effective methods to obtain high-purity (223)Ra from (227)Ac. We obtained (227)Ac from two surplus actinium-beryllium neutron generators. We retrieved the actinium/beryllium buttons from the sources and dissolved them in a sulfuric-nitric acid solution. A crude actinium solid was recovered from the solution by coprecipitation with thorium fluoride, leaving beryllium in solution. The crude actinium was purified to provide about 40 milligrams of actinium nitrate using anion exchange in methanol-water-nitric acid solution. The purified actinium was then used to generate high-purity (223)Ra. We extracted (223)Ra using anion exchange in a methanol-water-nitric acid solution. After the radium was separated, actinium and thorium were then eluted from the column and dried for interim storage. This single-pass separation produces high purity, carrier-free (223)Ra product, and does not disturb the (227)Ac/(227)Th equilibrium. A high purity, carrier-free (227)Th was also obtained from the actinium using a similar anion exchange in nitric acid. These methods enable efficient production of (223)Ra for research and new alpha-emitter radiopharmaceutical development. PMID:22697483

  7. Radium, thorium, and actinium extraction from seawater using an improved manganese-oxide-coated fiber

    Laboratory experiments were conducted to determine the efficiency with which improved manganese-oxide-coated acrylic fibers extract radium, thorium, and actinium from seawater. Tests were made using surface seawater spiked with 227Ac, 227Th and 223Ra. For sample volumes of approximately 30 liters and flow rates up to 0.5 liters per minute, radium and actinium are removed quantitatively. Approximately 80-95% of the thorium is removed under these same conditions. (Auth.)

  8. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces ∼100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 GeV protons

  9. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    Harvey, James T.; Nolen, Jerry; Vandergrift, George; Gomes, Itacil; Kroc, Tom; Horwitz, Phil; McAlister, Dan; Bowers, Del; Sullivan, Vivian; Greene, John

    2011-12-30

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces {approx}100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 Ge

  10. Methylnaltrexone bromide methanol monosolvate

    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.

  11. Neutron-Induced Fission of Actinium-227, Protactinium-231 and Neptunium-237: Mass Distribution

    Results of radiochemical studies on the mass distribution in the neutron-induced fission of actinium-227, protactinium-231 and neptunium-237 have been presented. This work has been carried out as part of a programme to determine the mass distribution in the fission of heavy elements as a function of Z and A. All irradiations have been carried out in the core of the swimming-pool type reactor APSARA with cadmium shielding wherever necessary. Relative yields of several fission product nuclides have been obtained by a method involving a comparison of the fission product activities from the respective targets with those formed from uranium-235 simultaneously irradiated. Thermal-neutron fission yields of uranium-235 have been assumed. These results indicate a predominantly asymmetric mass distribution in all the three cases, and also a distinct though small symmetric peak in the case of actinium-227. (author)

  12. A new method for the determination of low-level actinium-227 in geological samples

    We developed a new method for the determination of 227Ac in geological samples. The method uses extraction chromatographic techniques and alpha-spectrometry and is applicable for a range of natural matrices. Here we report on the procedure and results of the analysis of water (fresh and seawater) and rock samples. Water samples were acidified and rock samples underwent total dissolution via acid leaching. A DGA (N,N,N',N'-tetra-n-octyldiglycolamide) extraction chromatographic column was used for the separation of actinium. The actinium fraction was prepared for alpha spectrometric measurement via cerium fluoride micro-precipitation. Recoveries of actinium in water samples were 80 ± 8 % (number of analyses n = 14) and in rock samples 70 ± 12 % (n = 30). The minimum detectable activities (MDA) were 0.017-0.5 Bq kg-1 for both matrices. Rock sample 227Ac activities ranged from 0.17 to 8.3 Bq kg-1 and water sample activities ranged from below MDA values to 14 Bq kg-1of 227Ac. From the analysis of several standard rock and water samples with the method we found very good agreement between our results and certified values. (author)

  13. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    Momeni, M.H.

    1981-09-01

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore.

  14. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore

  15. In-source laser spectroscopy developments at TRILIS—towards spectroscopy on actinium and scandium

    Resonance Ionization Laser Ion Sources (RILIS) have become a versatile tool for production and study of exotic nuclides at Isotope Separator On-Line (ISOL) facilities such as ISAC at TRIUMF. The recent development and addition of a grating tuned spectroscopy laser to the TRIUMF RILIS solid state laser system allows for wide range spectral scans to investigate atomic structures on short lived isotopes, e.g., those from the element actinium, produced in uranium targets at ISAC. In addition, development of new and improved laser ionization schemes for rare isotope production at ISAC is ongoing. Here spectroscopic studies on bound states, Rydberg states and autoionizing (AI) resonances on scandium using the existing off-line capabilities are reported. These results allowed to identify a suitable ionization scheme for scandium via excitation into an autoionizing state at 58,104 cm − 1 which has subsequently been used for ionization of on-line produced exotic scandium isotopes.

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

    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.

  17. Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

    Raeder, S.; Bastin, B.; Block, M.; Creemers, P.; Delahaye, P.; Ferrer, R.; Fléchard, X.; Franchoo, S.; Ghys, L.; Gaffney, L. P.; Granados, C.; Heinke, R.; Hijazi, L.; Huyse, M.; Kron, T.; Kudryavtsev, Yu.; Laatiaoui, M.; Lecesne, N.; Luton, F.; Moore, I. D.; Martinez, Y.; Mogilevskiy, E.; Naubereit, P.; Piot, J.; Rothe, S.; Savajols, H.; Sels, S.; Sonnenschein, V.; Traykov, E.; Van Beveren, C.; Van den Bergh, P.; Van Duppen, P.; Wendt, K.; Zadvornaya, A.

    2016-06-01

    To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility that are needed for the first on-line studies of in-gas-jet laser spectroscopy. Different geometries for the gas outlet and extraction ion guides have been tested for their performance regarding the acceptance of laser ionized species as well as for their differential pumping capacities. The specifications and performance of the temporarily installed high repetition rate laser system, including a narrow bandwidth injection-locked Ti:sapphire laser, are discussed and first preliminary results on neutron-deficient actinium isotopes are presented indicating the high capability of this novel technique.

  18. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must...

  19. The metabolism of valethamate bromide, 1

    Valethamate bromide is widely used as a potent antispasmodic and antiulcerative agent. Studies were carried out to investigate the absorption, excretion and distribution of valethamate bromide in rats and men. When rats were given valethamate bromide-14C by subcutaneous injection, maximum blood concentration was reached at 1 to 2 hr after injection. The radioactivity was relatively highly distributed in kidney, liver, intestine and stomach. After subcutaneous injection, 57% of the administered dose was excreted in urine and 30% in feces within 48 hr. In the peroral administration, the transition of blood concentration levels did not present its peak clearly. Relatively high levels of radioactivity were present in stomach, intestine, kidney and liver. In the studies of biliary excretion used with unlabeled valethamate bromide, only when rats were administered by subcutaneous injection, 0.1 to 0.4% of the injected dose was recovered from the basic fraction of bile in 6 hr after injection. Our study revealed that there was difference between the urinary excretion rate of labeled and unlabeled valethamate bromide. And it was found that the transition of distributed amount into the tissues, which were abundant with lipid (as brain, fat and genitalia) and had the inclination to be distributed much in the second stage than in the first stage after administration, was not in proportion as blood concentrations. Consequently, it seems that valethamate bromide is partly metabolized to lipid-soluble compounds in body. When volunteers were administered Resitan by mouth, 2.7 to 5.5% of the dose was excreted in urine within 48 hrs. However, 42.5 to 47.5% of the administered dose was excreted in urine within 24 hr after intramuscular administration. Valethamate bromide was rapidly and virtually completely absorbed in both rats (s.c.) and men (i.m.), whereas 4 to 5% and 2.7 to 5.5% of the administered dose was excreted in rats and men after peroral administration. (author)

  20. Modeling and analysis of calcium bromide hydrolysis

    Lottes, Steven A.; Lyczkowski, Robert W.; Panchal, Chandrakant B.; Doctor, Richard D. [Energy Systems Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States)

    2009-05-15

    The main focus of this paper is the modeling, simulation, and analysis of the calcium bromide hydrolysis reactor stage in the calcium-bromine thermochemical water-splitting cycle for nuclear hydrogen production. One reactor concept is to use a spray of calcium bromide into steam, in which the heat of fusion supplies the heat of reaction. Droplet models were built up in a series of steps incorporating various physical phenomena, including droplet flow, heat transfer, phase change, and reaction, separately. Given the large heat reservoir contained in a pool of molten calcium bromide that allows bubbles to rise easily, using a bubble column reactor for the hydrolysis appears to be a feasible and promising alternative to the spray reactor concept. The two limiting cases of bubble geometry, spherical and spherical-cap, are considered in the modeling. Results for both droplet and bubble modeling with COMSOL MULTIPHYSICS trademark are presented, with recommendations for the path forward. (author)

  1. Methyl bromide residues in fumigated cocoa beans with particular reference to inorganic bromide

    Inorganic bromide residues and 14C-labelled methylated products (expressed as CH3Br equivalent) in cocoa beans fumigated with [14C]-methyl bromide have been determined by radiometric and chemical methods. Determination of 14C by direct combustion in an oxygen chamber followed by liquid scintillation counting confirmed previous findings with respect to the magnitude, distribution and chemical nature of the residues. Although recovery of added bromide was good, the values of total bromide obtained by the chemical method were only half of those estimated from the total residual 14C-activity. This is attributed to loss of organic (presumably, protein-bound) bromide. In agreement with the total 14C-labelled residue contents, total bromide in shells was 20 times greater than that in nibs. The low levels of residues in the nib (12ppm as CH3Br equivalent, 10ppm Br) and the further reduction of organic residues by roasting suggest that no toxicological and nutritional hazards may be expected from fumigation of cocoa beans with methyl bromide. (author)

  2. Radiolytic reduction reaction of colloidal silver bromide solution

    The reduction reaction of colloidal silver bromide (AgBr3)2- in nitrous oxide gas saturated solution of some alcohols: methanol, ethanol, 2-propanol and 2-methyl-2-propanol by γ-irradiation was studied spectrophotometrically in order to elucidate the mechanism of the formation of colloidal silver bromide (AgBr3)3- at ambient temperature. The amount of colloidal silver bromide formed increases in the order: i-PrOH, EtOH, MeOH. In t-BuOH, colloidal silver bromide did not form. The relative reactivities of alcohols for colloidal silver bromide was also studied kinetically. (author)

  3. Methyl bromide residues in fumigated cocoa beans

    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)

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

    Hsu, Susan; Singer, Philip C

    2010-04-01

    Bromide removal by anion exchange was explored for various water qualities, process configurations, and resin characteristics. Simulated natural waters containing different amounts of natural organic matter (NOM), bicarbonate, chloride, and bromide were treated with a polyacrylate-based magnetic ion exchange (MIEX) resin on a batch basis to evaluate the effectiveness of the resin for removal of bromide. While bromide removal was achieved to some degree, alkalinity (bicarbonate), dissolved organic carbon (DOC), and chloride were shown to inhibit bromide removal in waters with bromide concentrations of 100 and 300 microg/L. Water was also treated using a two-stage batch MIEX process. Two-stage treatment resulted in only a slight improvement in bromide removal compared to single-stage treatment, presumably due to competition with the high concentration of chloride which is present along with bromide in natural waters. In view of the relatively poor bromide removal results for the MIEX resin, a limited set of experiments was performed using polystyrene resins. DOC and bromide removal were compared by treating model waters with MIEX and two polystyrene resins, Ionac A-641 and Amberlite IRA910. The two polystyrene resins were seen to be more effective for bromide removal, while the MIEX resin was more effective at removing DOC. PMID:20045170

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

    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

  6. Nitroethylation of vinyl triflates and bromides.

    Padilla-Salinas, Rosaura; Walvoord, Ryan R; Tcyrulnikov, Sergei; Kozlowski, Marisa C

    2013-08-01

    A two-carbon homologation of vinyl triflates and bromides for the synthesis of homoallylic nitro products is described. This palladium-catalyzed double coupling of nitromethane exploits the anion stabilizing and leaving group properties of nitromethane, generating the homo allyl nitro products via a tandem cross-coupling/π-allylation sequence. The resultant process provides a mild and convenient entry to nitroethylated products, which are versatile precursors to β,γ-unsaturated carbonyls, homoallylic amines, and nitrile oxides. PMID:23885976

  7. Bromate oxidized from bromide during sonolytic ozonation.

    Lu, Ning; Wu, Xue-Fei; Zhou, Ji-Zhi; Huang, Xin; Ding, Guo-Ji

    2015-01-01

    Sonolytic ozonation (US/O3) is an effective way to degrade many pollutants in drinking water as the elevated mass transfer rate of ozone gas and the enhanced forming of hydroxyl radicals (OH). This work investigated the formation of bromate (BrO3(-)) from bromide (Br(-)) in sonolytic ozonation. At neutral pH, the bromate conversion rate ([BrO3(-)]/[Br(-)]0) was increased to 60% by ultrasound at continuous ozone flow (0-0.2Lmin(-1)), much higher than that without ultrasound or without bubbling. This indicates that the promoting effect of sonolysis on BrO3(-) formation is mainly due to the sonolytic decomposition of ozone and the enhancement of gas-liquid transfer. The [BrO3(-)]/[Br(-)]0 was increased with increasing pH. In addition, the reduction of HOBr/OBr(-) with ultrasound demonstrates that bromate may be inhibited as the bromide was formed with the H2O2 generation under ultrasound. This suggests the competition between bromate and bromide during the US/O3 led to the inhibition of bromate formation at high ozone flow. Therefore, our result reveals that the bromate formation under ultrasound is improved remarkably in US/O3 in quick treatment with proper ozone flow (<0.2Lmin(-1)). PMID:24931426

  8. [4-(Methoxycarbonylbenzyl]triphenylphosphonium bromide hemihydrate

    Shahid Hameed

    2008-02-01

    Full Text Available In the crystal structure of the title compound, C27H24O2P+·Br−·0.5H2O, there are intermolecular O—H...Br hydrogen bonds between the H atoms of the water of crystallization and the bromide anions. The three phenyl rings of the triphenylphosphonium moiety are at angles of 59.73 (15, 79.15 (14 and 82.81 (17° with the C/P/C planes.

  9. Exogenous bromide in the lactating rat influences iodine and bromide transfer to the suckling

    Pavelka, Stanislav

    Athens : University of Athens, 2005, s. 322-327. [International Symposium on Trace Elements in Human: New Perspectives /5./. Athens (GR), 13.10.2005-15.10.2005] Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * iodine * rat Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  10. Bromism from daily over intake of bromide salt.

    Frances, C; Hoizey, G; Lamiable, D; Millart, H; Trenque, T

    2003-01-01

    Bromide intoxication today is an infrequent disease, but preparations containing bromide are still available in nonprescription compounds, on the French market. We report a casewith bromide intoxication due to daily over intake (approximately 20 tablets per day; i.e. total elemental bromide intake approximately 6 g/day) of calcium bromo-galactogluconate (Calcibronat) for 1.5 months. A 30-year-old woman with a long history of psychotropic drug abuse was hospitalized in a psychiatric department for neuropsychological manifestations. She presented a seriously disturbed mental status with confusion, disorientation, auditory and visual hallucinations, and loss of short-time memory. A markedly increased serum bromide level of 1717 mg/L (21.5 mEq/L) measured on the first day after her admission confirmed the diagnosis of chronic bromism suspected based on her symptomatology. During her hospitalization, bromide plasma concentrations were measured and monitored using inductively coupled plasma mass spectrometry, a sensitive and very specific method. After withdrawal of the drug, the symptoms improved within 8 days. Serial bromide concentrations gradually declined throughout nearly 2 months of monitoring, until she was discharged from the hospital. We found an elimination half-life of bromide in blood of approximately of 10 days. This case demonstrates that, while today bromism occurs infrequently, it should still be included in the differential diagnosis of neuropsychiatric symptoms. PMID:12733857

  11. Evaluation of N-ethyl-N-methyl-morpholinium bromide and N-ethyl-N-methyl-pyrrolidinium bromide as bromine complexing agents in vanadium bromide redox flow batteries

    Evolution of bromine gas in the positive half cell of the Generation 2 (G2) vanadium bromide (V/Br) battery during charging is a concern which can be resolved by the use of bromine complexing agents. In this paper, for the first time, we report the effect of the addition of two quaternary ammonium bromides; N-ethyl-N-methyl-morpholinium bromide (MEM) and N-ethyl-N-methyl-pyrrolidinium bromide (MEP) to the positive and negative half cell electrolytes of the V/Br. Cyclic voltammetry (CV), linear sweep voltammetry and electrochemical impedance spectroscopy (EIS) studies showed that the addition of MEM–MEP effectively reduce Br2 vapours. Although the presence of MEM and MEP did not affect the mechanism of the electrode reactions, performance tests conducted in lab scale V/Br cells employing the VF11 cation exchange membrane resulted in lower average cell efficiencies possibly due to the increase in membrane resistance caused by membrane fouling

  12. Glycopyrronium bromide for the treatment of chronic obstructive pulmonary disease.

    Riario-Sforza, Gian Galeazzo; Ridolo, Erminia; Riario-Sforza, Edoardo; Incorvaia, Cristoforo

    2015-02-01

    Glycopyrronium bromide is a new long-acting muscarinic antagonist to be used once-daily, which is approved as a bronchodilator for the symptomatic maintenance treatment of adult patients with chronic obstructive pulmonary disease (COPD). In the Glycopyrronium bromide in chronic Obstructive pulmonary disease airWays trials, treatment with inhaled glycopyrronium bromide at 50 μg once daily achieved a significantly better lung function than placebo, as measured by the trough forced expiratory volume in 1 s in patients with moderate-to-severe COPD. The lung function improvement was maintained for up to 52 weeks. Other improved indexes were dyspnea scores, health status, exacerbation rates and time of exercise endurance. Studies comparing the efficacy of glycopyrronium versus tiotropium bromide found substantial equivalence of the two drugs. Glycopyrronium was generally well tolerated. These data add inhaled glycopyrronium bromide to the treatment of patients with moderate to severe COPD as an effective once-daily LAMA. PMID:25547422

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

    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.

  14. Groundwater seepage from the Ranger uranium mine tailings dam: radioisotopes of radium, thorium and actinium. Supervising Scientist report 106

    Monitoring of bores near the Ranger uranium mine tailings dam has revealed deterioration in water quality in several bores since 1983. In a group of bores to the north of the dam, increases have been observed of up to 500 times for sulphate concentrations and of up to 5 times for 226Ra concentrations. Results are presented here of measurements of members of the uranium, thorium and actinium decay series in borewater samples collected between 1985 and 1993. In particular, measurements of all four naturally-occurring radium isotopes have been used in an investigation of the mechanism of radium concentration changes. For the most seepage-affected bores the major findings of the study include: 228Ra/226Ra 223Ra /226Ra and 224Ra/228Ra ratios all increased over the course of the study; barium concentrations show high seasonal variability, being lower in November than May, but strontium concentrations show a steady increase with time. Calculations show that the groundwater is probably saturated with respect to barite but not with respect to celestite or anglesite; sulphide concentrations are low in comparison with sulphate, and are higher in November than in May; and 227Ac concentrations have increased with time, but do not account for the high 223Ra/226Ra ratios. It is concluded on the basis of these observations that increases in Ra isotope concentrations observed in a number of seepage-affected bores arise from increases in salinity leading to desorption of radium from adsorption sites in the vicinity of the bore rather by direct transport of radium from the tailings. Increased salinity is also causing the observed increases in 227Ac and strontium concentrations, while formation of a barite solid phase in the groundwater is causing the removal of some radium from solution. This is the cause of the increasing radium isotope ratios noted above

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

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

    2013-07-01

    Brines generated from oil and natural gas production, including flowback water and produced water from hydraulic fracturing of shale gas, may contain elevated concentrations of bromide (~1 g/L). Bromide is a broad concern due to the potential for forming brominated disinfection byproducts (DBPs) during drinking water treatment. Conventional treatment processes for bromide removal is costly and not specific. Selective bromide removal is technically challenging due to the presence of other ions in the brine, especially chloride as high as 30-200 g/L. This study evaluates the ability of solid graphite electrodes to selectively oxidize bromide to bromine in flowback water and produced water from a shale gas operation in Southwestern PA. The bromine can then be outgassed from the solution and recovered, as a process well understood in the bromine industry. This study revealed that bromide may be selectively and rapidly removed from oil and gas brines (~10 h(-1) m(-2) for produced water and ~60 h(-1) m(-2) for flowback water). The electrolysis occurs with a current efficiency between 60 and 90%, and the estimated energy cost is ~6 kJ/g Br. These data are similar to those for the chlor-alkali process that is commonly used for chlorine gas and sodium hydroxide production. The results demonstrate that bromide may be selectively removed from oil and gas brines to create an opportunity for environmental protection and resource recovery. PMID:23726709

  16. Sodium bromide acts as a contrast material on DEXA scanning.

    Chaisson, T G; Ryan, D H

    1994-02-01

    Subjects undergoing a series of procedures to determine body composition, including dual-energy x-ray absorptiometry (DEXA) scanning and extracellular water volume determination by bromide dilution, demonstrated abnormal DEXA scans in some cases. Oral doses of sodium bromide in the stomach were detected on total body DEXA scanning as contrast material. The physical principles that cause bromide to be imaged in a manner similar to calcium by the DEXA scanner are discussed so that other investigators may be aware of this potential pitfall in body composition analysis. PMID:8195668

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

    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).

  18. Kinetics and Mechanism of the Chlorate-Bromide Reaction.

    Sant'Anna, Rafaela T P; Faria, Roberto B

    2015-11-01

    The chlorate-bromide reaction, ClO3(-) + 6Br(-) + 6H(+) → 3Br2 + Cl(-) + 3H2O, was followed at the Br3(-)/Br2 isosbestic point (446 nm). A fifth-order rate law was found: (1)/3 d[Br2]/dt = k[ClO3(-)][Br(-)][H(+)](3) (k = 5.10 × 10(-6) s(-1) L(4) mol(-4)) at 25 °C and I = 2.4 mol L(-1). At high bromide concentrations, the bromide order becomes close to zero, indicating a saturation profile on bromide concentration, similar to the chloride saturation profile observed in the chlorate-chloride reaction. A mechanism is proposed that considers the formation of the intermediate BrOClO2(2-), similar to the intermediate ClOClO2(2-) proposed in the mechanism of the chlorate-chloride reaction. PMID:26467822

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

    Thomas, W. B.

    1996-01-01

    Methyl bromide is used extensively on a global basis as a pesticide against nematodes, weeds, insects, fungi, bacteria, and rodents. As a soil fumigant, it is used in significant quantities in the production of strawberry and tomato, as well as other agriculture commodities. Grain, fresh fruit, forestry products, and other materials are fumigated with methyl bromide to control pest infestations during transport and storage. Structures also are treated with this chemical to control wood-destro...

  20. Quantum Chemistry Study on Dissociation of Oxalyl Bromide

    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.

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

    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...

  2. Performance of large lanthanum bromide scintillators

    Cerium-doped lanthanum bromide, LaBr3(Ce), scintillator possesses several outstanding properties that make it an attractive choice for security, medical, and geophysical radiation detection applications. Among these properties are good density (5.1 g/cc), excellent energy resolution (∼3% full-width at half-maximum (FWHM) at Eγ=662 keV), brightness (>65,000 photon/MeV), and speed, (τd100 cc). The anisotropic thermal expansion exhibited by this material makes it difficult to grow large ingots due to the build up of internal stresses as it cools, causing fracturing. Recently, Saint-Gobain Crystals has achieved successful growths of large unfractured ingots, from which large detectors have been assembled (>150 cc). The outstanding properties seen in small pieces are retained up to at least 155 cc (the largest assembled into a single detector thus far). A cylindrical LaBr3(Ce=5%) crystal with dimensions of diameter=51 mm, and length=76 mm achieves energy resolution of 3.1% FWHM at 662 keV, and brightness of 165% of NaI with good uniformity throughout the crystal. Scintillation light yield and energy resolution have been examined as a function of crystal size and γ-ray energy. Spatial mapping of a large crystal was examined and shown to be uniform. Large crystals enable accurate measurements of the intrinsic γ-ray background from 138La (0.09% nat. abun., γ-ray emission at 1436 and 789 keV). This background is shown to scale appropriately in size with theoretical calculations

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

    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

  4. Interaction of cephradine monohydrate with Cetyldimethylethylammonium Bromide

    Highlights: • We carry out the interaction of CDM drugs with CDMEAB conductometrically. • We examine the effect of drugs on the critical micelle concentration of CDMEAB. • Two critical micelle concentrations are obtained for drug-CDMEAB system. • Electrostatic and hydrophobic interactions between drug and surfactant are proposed. • Effect of KCl and K2SO4 is observed on interaction between drug and surfactant. -- Abstract: Interaction of cephradine monohydrate (CDM) with Cetyldimethylethylammonium Bromide (CDMEAB) has been studied by conductance measurements in pure form and in the presence of salts like potassium chloride (KCl) and potassium sulphate (K2SO4) over the temperature range of (298.15 to 318.15) K. From conductivity vs. surfactant concentration plots, two critical micelle concentrations like c1∗ and c1∗ were obtained for (CDM + CDMEAB) systems. The variation of c∗ values of CDMEAB in the presence of CDM is the indication of the interaction between CDM and CDMEAB. For the (CDM + CDMEAB) system, the values of c∗ values are higher in magnitude in contrast to that of pure CDMEAB in water over the range in temperature studied. In aqueous solutions of KCl and K2SO4, the c∗ values are changed with the increase of the concentration of salts and hence the micellization is dependent on salt concentration. The ΔGm0 values were negative and the spontaneity of micellization process is found to be increased with increase of temperature. The values of ΔH1,m0 and ΔS1,m0 indicated that the drug mediated CDMEAB aggregation in water was controlled at lower temperatures while at higher temperatures the aggregation was both enthalpy and entropy controlled. The ΔH2,m0 and ΔS2,m0 values revealed that the micellization in water was both enthalpy and entropy controlled at lower and higher temperatures though the effect of entropy at middle temperature was dominant. The results indicated that binding interactions between CDM and CDMEAB are both

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

    Moumeni, Ouarda; Hamdaoui, Oualid

    2012-05-01

    Sonochemical oxidation has been investigated as a viable advanced oxidation process (AOP) for the destruction of various pollutants in water. Ultrasonic irradiation generates ()OH radicals that can recombine, react with other gaseous species present in the cavity, or diffuse out of the bubble into the bulk liquid medium where they are able to react with solute molecules. The extent of degradation of an organic dye such as malachite green (MG) is limited by the quantity of hydroxyl radicals diffused from cavitation bubbles. In this work, the effect of bromide ions on sonolytic degradation of MG was investigated. The obtained results clearly demonstrated the considerable enhancement of sonochemical destruction of MG in the presence of bromide. No significant differences were observed in the presence of chloride and sulfate, excluding the salting-out effect. Positive effect of bromide ions, which increases with increasing bromide level and decreasing MG concentration, is due to the generation of dibromine radical anion (Br(2)(-)) formed by reaction of Br(-) with ()OH radicals followed by rapid complexation with another anion. The generated Br(2)(-) radicals, reactive but less than ()OH, are likely able to migrate far from the cavitation bubbles towards the solution bulk and are suitable for degradation of an organic dye such as MG. Additionally, Br(2)(-) radicals undergo radical-radical recombination at a lesser extent than hydroxyl radicals and would be more available than ()OH for substrate degradation, both at the bubble surface and in the solution bulk. This effect compensates for the lower reactivity of Br(2)(-) compared to ()OH toward organic substrate. Addition of bromide to natural and sea waters induces a slight positive effect on MG degradation. In the absence of bromide, ultrasonic treatment for the removal of MG was promoted in complex matrices such as natural and sea waters. PMID:21911308

  6. Oxidation of manganese(II) during chlorination: role of bromide.

    Allard, S; Fouche, L; Dick, J; Heitz, A; von Gunten, U

    2013-08-01

    The oxidation of dissolved manganese(II) (Mn(II)) during chlorination is a relatively slow process which may lead to residual Mn(II) in treated drinking waters. Chemical Mn(II) oxidation is autocatalytic and consists of a homogeneous and a heterogeneous process; the oxidation of Mn(II) is mainly driven by the latter process. This study demonstrates that Mn(II) oxidation during chlorination is enhanced in bromide-containing waters by the formation of reactive bromine species (e.g., HOBr, BrCl, Br2O) from the oxidation of bromide by chlorine. During oxidation of Mn(II) by chlorine in bromide-containing waters, bromide is recycled and acts as a catalyst. For a chlorine dose of 1 mg/L and a bromide level as low as 10 μg/L, the oxidation of Mn(II) by reactive bromine species becomes the main pathway. It was demonstrated that the kinetics of the reaction are dominated by the adsorbed Mn(OH)2 species for both chlorine and bromine at circumneutral pH. Reactive bromine species such as Br2O and BrCl significantly influence the rate of manganese oxidation and may even outweigh the reactivity of HOBr. Reaction orders in [HOBr]tot were found to be 1.33 (±0.15) at pH 7.8 and increased to 1.97 (±0.17) at pH 8.2 consistent with an important contribution of Br2O which is second order in [HOBr]tot. These findings highlight the need to take bromide, and the subsequent reactive bromine species formed upon chlorination, into account to assess Mn(II) removal during water treatment with chlorine. PMID:23859083

  7. Radioactive bromide partition test in the diagnosis of tuberculous meningitis

    The utility of the radioactive bromide partition test in differentiating tuberculous meningitis (TBM) from other forms of meningitis has been assessed. The test was carried out in 19 patients with TBM, 6 patients with partially treated pyogenic meningitis and 17 non-meningitis controls. Eighteen of the 19 TBM patients gave bromide partition ratio (BPR) value below 1.3 while the value was above this level in all control patients including partially treated meningitis. The results indicate that the test is useful in the differential diagnosis of TBM. (author)

  8. Chemistry of pyrrolizines; reactions with cyanogen bromide and trifluoroacetic anhydride

    Verboom, W.; Visser, G.W.; Reinhoudt, D.N.

    1982-01-01

    Interaction of the pyrrolizine 3 with cyanogen bromide in a tetrahydrofuran/water mixture affords addition to the enamine double bond with formation of 5 which can be aromatized to 6 by silica gel. Reaction of 6 with cyanogen bromide in the same solvent mixture yields the indoline 8a which structure is proved in a chemical way by conversion of the product into the aldehyde 8d. The different reaction pathway is discussed in terms of steric hindrance by the ester groups. Treatment of 6 with tri...

  9. Stability analysis for complexes in calcium-alkali bromide solutions

    We discuss the dependence of the stability of tetrahedral complexes in molten halide mixtures on the halogen species. This is done by calculating the equilibrium concentration of (CaBr4)2- complexes in calcium-alkali bromide solutions as a function of composition, in comparison with earlier calculations on the calcium-alkali chloride systems. The comparison supports a possible trend of increasing stability from chlorides to bromides, provided that halogen polarizability or chemical bonding contribute appreciably to the binding of a complex. Supporting evidence is noted and further experiments are suggested. (author). 10 refs, 2 figs

  10. Radioactive bromide partition test in early diagnosis of tuberculous meningitis

    Use of the radioactive bromide partition test in the early diagnosis of tuberculous meningitis is described briefly. Results of the (1) normal control group, (2) tuberculous menigitis group and (3) non-tuberculous lymphocytic meningitis are reported. Dose rates administered are specified. (K.B.)

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

    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...

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

    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...

  13. Bromide interference with iodine metabolism in the rat

    Pavelka, Stanislav

    Hersonissos: ISTERH, 2007. E073-E073. [Conference International Society for Trace Element Research in Humans /8./. 21.10.2007-26.10.2007, Hersonisssos] R&D Projects: GA AV ČR(CZ) KJB401630701 Institutional research plan: CEZ:AV0Z50110509 Keywords : spr2 * bromide * iodine * metabolism Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  14. Bromide interference with iodine metabolism in the rat

    Pavelka, Stanislav

    2008-01-01

    Roč. 24, Suppl.1 (2008), S97-S98. ISSN 0742-2091. [Trace Elements in Diet , Nutrition and Health. 21.10.2008-26.10.2008, Hersonissos] Institutional research plan: CEZ:AV0Z50110509 Keywords : cpr1 * bromide * iodine * metabolism Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

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

    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)

  16. Methyl bromide phase out could affect future reforestation efforts

    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...

  17. Effects of exogenous bromide on the metabolism of iodine

    Pavelka, Stanislav

    Athens : University of Athens, 2003 - (Ermidou-Pollet, S.; Pollet, S.), s. 615-624 [Trace Elements in Human : New Perspectives /4./. Athens (GR), 09.10.2003-11.10.2003] Institutional research plan: CEZ:AV0Z5011922 Keywords : bromide * iodine * metabolism Subject RIV: ED - Physiology

  18. Palladium(0)-catalyzed methylenecyclopropanation of norbornenes with vinyl bromides.

    Mao, Jiangang; Bao, Weiliang

    2014-05-16

    Highly strained methylenecyclopropane derivatives have been achieved via a novel and efficient Pd(0)-catalyzed domino reaction. The formal [2 + 1] cycloaddition reaction of vinyl bromides to norbornenes involves a Heck-type coupling and a C(sp(2))-H bond activation. PMID:24784731

  19. Bromide interference with iodine metabolism: goitrogenic and whole-body effects of excessive inorganic bromide in the rat

    Pavelka, Stanislav

    Oxford: Academic Press, 2009 - (Preedy, V.; Burrow, G.; Watson, R.), s. 587-595 ISBN 978-0-12-374135-6 Grant ostatní: EC(XE) LSHG-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * iodine * metabolism Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

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

    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

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

    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...

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

    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.

  3. 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

    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...

  4. [2,6-Bis(dimethylaminomethylphenyl]selenium bromide monohydrate

    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.

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

    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)

  6. Very long terahertz free induction decay in gaseous hydrogen bromide

    Free induction decay radiation was observed in low pressure hydrogen bromide that continued for more than 180 ns after excitation by a terahertz pulse from a free electron laser. The signal was measured in real time using an ultrafast Schottky diode detector. Such a signal corresponds in frequency domain spectral resolution to about 10 MHz, which allows for resolution of the isotopic and quadrupole structure of the absorption line. (letter)

  7. Thyrotoxic effects of exogenous bromide in the rat

    Pavelka, Stanislav

    Bratislava: Slovak University of Technology, 2008 - (Manová, A.; Čacho, F.), s. 173-174 ISSN 1335-3160. [Priemyselná toxikológia 08 /28./. Tatranská Štrba (SK), 18.06.2008-20.06.2008] Grant ostatní: GA AV ČR(CZ) KJB401630701; MYORES(XE) 511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : thyroid gland * bromide * rat Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  8. High-speed Laser Micromachining with Copper Bromide Laser

    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.

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

    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)

  10. ELECTROCHEMICAL REDUCTION OF DODECYLPYRIDINIUM BROMIDE IN APROTIC SOLVENTS: MECHANISTIC STUDIES

    Hromadová, Magdaléna; Pospíšil, Lubomír; Sokolová, Romana; Kolivoška, Viliam

    2011-01-01

    Roč. 76, č. 12 (2011), s. 1895-1908. ISSN 0010-0765 R&D Projects: GA AV ČR IAA400400802; GA ČR GA203/08/1157; GA ČR GA203/09/0705; GA MŠk(CZ) MEB041006 Institutional research plan: CEZ:AV0Z40400503 Keywords : spectroelectrochemistry * dodecylpyridinium bromide * mechanistic studies Subject RIV: CG - Electrochemistry Impact factor: 1.283, year: 2011

  11. 4-Hydroxy-1,2,6-trimethylpyridinium bromide monohydrate

    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].

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

    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.

  13. L-Tryptophan L-tryptophanium bromide: Anhydrous and monohydrate

    Ghazaryan, V. V.; Giester, G.; Fleck, M.; Petrosyan, A. M.

    2015-12-01

    L-Tryptophan L-tryptophanium bromide (I) and L-tryptophan L-tryptophanium bromide monohydrate (II) are new salts with (A⋯A+) type dimeric cation. The salt (I) crystallizes in the monoclinic system (space group P21, Z = 2) and is isostructural with respective chloride (V.V. Ghazaryan et al., Spectrochim. Acta A 136(2015) 743-750), while the salt (II) was obtained previously (T. Takigawa et al., Bull. Chem. Soc. Jap. 39(1966) 2369-2378) and described as hemyhydrate without structure determination. The salt (II) crystallizes in orthorhombic system (space group P212121, Z = 4). The dimeric cations in (I) and (II) are formed by O-H⋯O hydrogen bonds with the O⋯O distances equal to 2.538(3) Å and 2.481(3) Å respectively. The infrared and Raman spectra of the crystals are studied and compared with the spectra of L-tryptophan L-tryptophanium chloride and L-tryptophanium bromide.

  14. Palladium-catalyzed thiocarbonylation of aryl, vinyl, and benzyl bromides.

    Burhardt, Mia N; Ahlburg, Andreas; Skrydstrup, Troels

    2014-12-19

    A catalytic protocol for synthesis of thioesters from aryl, vinyl, and benzyl bromides as well as benzyl chlorides was developed using only stoichiometric amounts of carbon monoxide, produced from a solid CO precursor inside a two-chamber system. As a catalytic system, the combination of bis(benzonitrile) palladium(II) chloride and Xantphos furnished the highest yields of the desired compounds, along with the weak base, NaOAc, in anisole at 120 °C. The choice of catalytic system as well as solvent turned out to be important in order to ensure a high chemoselectivity in the reaction. Both electron-rich and electron-deficient aryl bromides worked well in this reaction. Addition of 1 equiv of sodium iodide to the reaction improved the chemoselectivity with the electron-deficient aryl bromides. The thiol scope included both aryl and alkyl thiols, including 2-mercaptobenzophenones, whereby a thiocarbonylation followed by a subsequent McMurry coupling yielded differently substituted benzothiophenes. It was demonstrated that the methodology could be applied for (13)C introduction into the thiophene ring. PMID:24919457

  15. High bromide intake in the lactating rat significantly influences transfer of iodine and bromide via mother's milk

    Pavelka, Stanislav

    Brno : Masarykova univerzita, 2007. s. 13-14. ISBN 80-120-3942-6. [Pracovní setkání biochemiků a molekulárních biologů /10./. 08.02.2006-09.02.2006, Brno] Institutional research plan: CEZ:AV0Z50110509 Keywords : spr2 * bromide * iodine * rat Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  16. High bromide intake in the lactating rat significantly influences transfer of iodine and bromide via mother's milk

    Pavelka, Stanislav

    Brno : Masarykova univerzita v Brně, 2006 - (Wimmerová, M.; Beneš, P.). s. 13-14 ISBN 80-210-3942-6. [Pracovní setkání biochemiků a molekulárních biologů /10./. 08.02.2006-09.02.2006, Brno] Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * iodine * mother's milk Subject RIV: ED - Physiology

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

    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

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

    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.

  19. A study of bromide in the Mandovi-Zuari river system of Goa

    de Souza, Francisca P.; Dalal, V. N. Kamat

    1985-10-01

    Bromide was the subject of detailed investigation in the Mandovi-Zuari river system and information was compiled on its spatial and temporal distribution. A simple mixture relation of Carpenter et al. was applied and seawater percentage and bromide concentrations were computed. The variation of bromide with chlorinity was linear indicating the purely conservative character of bromide and its seawater origin. Seawater ranged between 1 and 3% in monsoon, 76 and 91% in post-monsoon and 92 and 97% in pre-monsoon in the Mandovi-Zuari river system. As the bromide concentration varied linearly with chlorinity both longitudinally and depthwise, it followed that bromide exhibited a simple distribution pattern established by conservative mixing.

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

    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...

  1. On the complexing of certain transition metal bromides with trimecaine

    Synthesis and IR spectroscopy of the structure of cadmium bromide coordination compounds and certain other elements with trimecaine (diethylamino-2,4-6-trymethylacetanilidine, L) are carried out. Complexes of the CdLBr2(1) and Cd(LH)2Br4(2) composition are prepared, this molecular structure is established. In complex 1 cadmium atom is shown to be coordinately related to the nitrogen atom of the ternary aminogroup; in complex 2 the bond between the CdBr42- anion and ternary nitrogen atom of the ligand is of the ionic character

  2. Interaction between gaseous ozone and crystalline potassium bromide

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

    2016-07-01

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

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

    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.

  4. Bacterial Oxidation of Methyl Bromide in Fumigated Agricultural Soils

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

    1997-01-01

    The oxidation of [(sup14)C]methyl bromide ([(sup14)C]MeBr) to (sup14)CO(inf2) was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCl(inf3)NO(inf2)). 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-kille...

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

    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...

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

    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.

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

    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.

  8. Synthesis and Characterization of Mercuric Bromide-Phenothiazine Complexes

    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.

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

    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.

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

    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.

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

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

    1985-01-01

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

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

    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. Removal of bromide by aluminium chloride coagulant in the presence of humic acid.

    Ge, Fei; Shu, Haimin; Dai, Youzhi

    2007-08-17

    Bromide can form disinfection by-products (DBPs) in drinking water disinfection process, which have adverse effects on human health. Using aluminium chloride as a model coagulant, removal of bromide by coagulation was investigated in the absence or presence of humic acid (HA) in synthetic water and then was conducted in raw water. Results demonstrated that in synthetic water, 93.3-99.2% removal efficiency of bromide was achieved in the absence of HA with 3-15 mg/L coagulant, while 78.4-98.4% removal efficiency of bromide was obtained in the presence of HA with the same coagulant dosage and 86.8-98.8% HA was removed simultaneously. Bromide in raw water was removed 87.0% with 15 mg/L coagulant. HA apparently reduced the removal of bromide with low coagulant dosage or at high pH, while minor influence on removal of bromide was observed with high coagulant dosage or at low pH. Thus, bromide could be reduced effectively by enhanced coagulation in drinking water treatment. PMID:17289257

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

    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

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

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

  16. The method of molecular dynamics in ethidium bromide-DNA interaction research

    The interaction of ethidium bromide with the DNA by the method of molecular dynamics was studied. The geometric and energy parameters of DNA-ethidium bromide connectivity had been calculated. A comparative analysis of the experimentally identified connectivity parameters by different methods and parameters of molecular dynamics method had been carried out

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

    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.

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

    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.

  19. Timing resolution measurements of a 3 in. lanthanum bromide detector

    Galli, L., E-mail: luca.galli@pi.infn.it [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); De Gerone, M. [INFN Sezione di Genova, Largo Dodecaneso 33, 16146 Genova (Italy); Dipartimento di Fisica dell' Università degli Studi di Genova, Largo Dodecaneso 33, 16146 Genova (Italy); Dussoni, S. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Nicolò, D. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica dell' Università degli Studi di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Papa, A. [Paul Scherrer Institute PSI, CH-5232 Villigen (Switzerland); Tenchini, F. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica dell' Università degli Studi di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Signorelli, G. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy)

    2013-08-01

    Cerium-doped lanthanum bromide (LaBr{sub 3}:Ce) is a scintillator that presents very good energy and timing resolutions and it is a perfect candidate for photon detector in future experiments to search for lepton flavor violation as in μ→eγ or μ→e conversion. While energy resolution was thoroughly investigated, timing resolution at several MeV presents some experimental challenge. We measured the timing resolution of a 3 in.×3 in. cylindrical LaBr{sub 3}(Ce) crystal versus few reference detectors by means of a nuclear reaction from a Cockcroft–Walton accelerator that produces coincident γ-rays in the 4.4–11.6 MeV range. Preliminary results allow us to extrapolate the properties of a segmented γ-ray detector in the 50–100 MeV range.

  20. Optical studies of X-irradiated sodium bromide single crystals

    Optical absorption of sodium bromide single crystals colored by X-rays for durations ranging from 8 hours to 200 hours at room temperature has been studied. Two well-resolved absorption bands one at 535 nm (F-band) and the other at 255 nm have been observed in all the samples. Another band at 840 nm (M-band) has also been observed when the irradiation time was extended to 200 hours. A band at 770 nm has been detected for the first time during the process of optical bleaching. The effects of optical bleaching with F-band light on these absorption bands have been studied in detail for durations ranging from a few seconds to 1820 minutes at temperature below the coloration temperature. (author)

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

    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)

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

    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.

  3. Radioiodine tracers as useful tools in studies of thyrotoxic effects of exogenous bromide and perchlorate ions

    With the use of 125I and 131I radionuclides, we followed the effects of exogenous bromide and perchlorate ions on the metabolism of iodine and of thyroid hormone in the rat. The presumed thyrotoxic effects of bromide and perchlorate have been confirmed and quantified. Correct assay conditions for the radiometric determination of the enzyme activity of thyroid peroxidase (TPO) have been established. The use of the adapted radiometric assay revealed a divergent influence of bromide and perchlorate ions on the TPO activity in the rat thyroids. Excessive bromide exerted a biphasic effect, depending on the extent of bromide intake in the animals. In contrast, in all the rats that were administered with high amounts of perchlorate were found elevated TPO activities. (author)

  4. The reactivity of phenancyl bromide under β-cyclodextrin as supramolecular catalyst: a computational survey.

    Wan, Yali; Wang, Xueye; Liu, Na

    2015-05-01

    Phenacyl bromide as one starting material in multicomponent reactions (MCRs) with β-cyclodextrin (β-CD) as catalyst can get an excellent yield in short reaction times. The interaction of β-CD with phenacyl bromide plays an important role in this process. This paper studies the complex of β-CD with phenacyl bromide using density functional theory (DFT) method. Energy is investigated to find out the lowest energy of two possible complexation models. Hydrogen bonds are researched on the basis of natural bonding orbital (NBO) analysis. The relative position between phenacyl bromide and β-CD is confirmed by (1)H nuclear magnetic resonance ((1)HNMR). The results of frontier molecular orbitals and charge distribution reveal that β-CD catalyst improves the reactivity and electrophilicity of phenacyl bromide, meanwhile, the carbonyl group of phenacyl bromide more easily gives a carbocationic intermediate in the presence of β-CD as catalyst. The reactivity of phenancyl bromide under β-CD as supramolecular catalysis is improved. PMID:25929992

  5. Methyl bromide cycling in a warm-core eddy of the North Atlantic Ocean

    Yvon-Lewis, SA; Butler, JH; Saltzman, Es; Matrai, PA; King, DB; R. Tokarczyk; Moore, RM; Zhang, JZ

    2002-01-01

    We conducted a detailed investigation of the evolution of methyl bromide concentrations, degradation rates, and ventilation rates for 26 days in a naturally contained, warm-core eddy of the North Atlantic Ocean. This is the first study of the oceanic cycling of methyl bromide in a natural, contained system with a complete suite of supporting measurements of physical and chemical variables. Methyl bromide concentrations in the mixed layer ranged from 2.3 to 4.2 nmol m−3, degradation rates rang...

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

    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.

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

    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)

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

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

    2015-10-01

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

  9. Chloride, bromide and iodide scintillators with europium doping

    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.

  10. 4-Bromophenacyl bromide specifically inhibits rhoptry secretion during Toxoplasma invasion.

    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

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

    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.

  12. Evaluation of Alkali Bromide Salts for Potential Pyrochemical Applications

    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.

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

    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. Improved spectrometric characteristics of thallium bromide nuclear radiation detectors

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

    1999-01-01

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

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

    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.

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

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

    2014-03-01

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

  17. 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

    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.

  18. Radioactive bromide partition test in the diagnosis of tubercular meningitis in children

    Radioactive 82bromide (0.64 μCi/kg) was administered orally to 52 children in the age group of 0-12 yr, 41 patients with suspected tubercular meningitis (TBM) and 11 with non-tubercular meningitis. The bromide activity in the serum and CSF were obtained at 48 h. A serum to CSF bromide partition ratio (BPR) of 1.9 and below was highly specific for TBM, and was seen in 38 of 41 patients, this included the 11 patients where the diagnosis of tuberculosis was proved by AFB isolation and/or histopathology. In the non-tubercular group BPR was above 1.9 in all the patients with no false positivity. The present study re-affirms the value of bromide partition test in the diagnosis of tubercular meningitis. (author)

  19. Electrochemical removal of bromide and reduction of THM formation potential in drinking water.

    Kimbrough, David Eugene; Suffet, I H

    2002-11-01

    Trihalomethanes (THMs), a by-product of the chlorination of natural waters containing dissolved organic carbon and bromide, are the focus of considerable public health concern and regulation due to their potential as a carcinogen by ingestion. This paper presents a promising new water treatment process that lowers the concentration of bromide in drinking water and thus, lowers the THM formation potential. Bromide is oxidized by electrolysis to bromine and then the bromine apparently volatilized. The electrolyzed water, when chlorinated, produces measurably lower amounts of THMs and proportionately fewer brominated THMs, which are of greater public health concern than the chlorinated THMs. Removing bromide should also reduce the formation of other disinfection by-products such as bromate and haloacetic acids. PMID:12448534

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

    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.

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

    Leao, Cedric Rocha; Lordi, Vincenzo

    2015-11-24

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

  2. Interaction of removal Ethidium Bromide with Carbon Nanotube: Equilibrium and Isotherm studies

    Moradi, Omid; Norouzi, Mehdi; FAKHRI, Ali; Naddafi, Kazem

    2014-01-01

    Drinking water resources may be contaminated with Ethidium Bromide (EtBr) which is commonly used in molecular biology laboratories for DNA identification in electrophoresis. Carbon nanotubes are expected to play an important role in sensing, pollution treatment and separation techniques. In this study adsorption of Ethidium Bromide on single-walled carbon nanotubes (SWCNTs) and carboxylate group functionalized single-walled carbon nanotube (SWCNT-COOH) surfaces have been investigated by UV–vi...

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

    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...

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

    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)

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

    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...

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

    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...

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

    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.

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

    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 (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

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

    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.

  10. Partial molar volume and isentropic compressibility of symmetrical and asymmetrical quaternary ammonium bromides in aqueous solution

    Highlights: • Structural effects of the cations on surrounding water molecules are discussed. • Alkyl-chain geometry determines the hydration of Bu4N+ isomers. • The “compactness” in the hydration shells varies significantly among the isomers. - Abstract: Values of apparent molar volume and isentropic compressibility of symmetric and asymmetric isomers of tetrabutylammonium bromide, namely tetra-n-butylammonium bromide, tetra-iso-butylammonium bromide, tetra-sec-butylammonium bromide, di-n-butyl-di-iso-butylammonium bromide and di-n-butyl-di-sec-butylammonium bromide, in aqueous solution were determined from density and speed of sound measurements. These properties were obtained as a function of molal concentration within the range of 0.01 < m/mol · kg−1 < 0.1 covering temperatures from 278.15 ⩽ T/K ⩽ 293.15. The partial molar volumes and the apparent isentropic molar compressibility at infinite dilution were calculated and their dependence on temperature examined. The results show that cations with sec-butyl chains have larger structural volumes compared to those with iso-butyl chains. In addition, cations with sec-butyl chains induce smaller structural changes in their hydration shell than the others

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

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

    2002-01-01

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

  12. Structure and scintillation of Eu2+-activated calcium bromide iodide

    We report the structure and scintillation properties of Eu2+-activated calcium bromide iodide. CaBr0.7I1.3 was the only composition that could be synthesized in the CaBr2–CaI2 system. The compound has an effective atomic number of 47 and crystallizes in a trigonal crystal system with the R-3 space group and a density of 3.93 g/cc. The structure is layered and contains Ca in an octahedral environment with the Br/I anions jointly occupying a single site. Eu2+-activated samples show an intense narrow emission, characteristic of the 5d–4f transition of Eu2+, when excited with UV or X-rays. The sample with 0.5% Eu shows a light output of 63,000 ph/MeV at 662 keV with 96% of the light emitted with a monoexponential decay time of 1332 ns. An energy resolution of 10.4% full width at half maximum (FWHM) has been achieved for 662 keV gamma rays at room temperature. - Highlights: • CaBr0.7I1.3 is the only composition that formed in the CaBr2–CaI2 system. • Crystallizes in a trigonal crystal system with the R-3 space group. • Eu2+-activation yields scintillator with bright blue emission centered at 465 nm. • Light output is 63,000 ph/MeV with 10.4% energy resolution at 662 keV. • Monoexponential decay time of 1332 ns

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

    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

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

    Hoobakht, Fatemeh; Ganji, Fariba, E-mail: fganji@modares.ac.ir; Vasheghani-Farahani, Ebrahim [Tarbiat Modares University, Biomedical Engineering Group, Chemical Engineering Department (Iran, Islamic Republic of); Mousavi, Seyyed Mohammad [Tarbiat Modares University, Biotechnology Group, Chemical Engineering Department (Iran, Islamic Republic of)

    2013-09-15

    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 Degree-Sign 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.

  15. The use of lanthanum bromide detectors for nuclear safeguards applications

    Lanthanum Bromide (LaBr3) is a type of scintillation detector that has become commercially available recently. According to the manufacturer and studies conducted at a laboratory level, this new gamma-ray detector presents improved characteristics in comparison with traditional sodium iodine (NaI) detectors. Better energy resolution, relative efficiency and stability with temperature are some of the features that may impact positively the performance of the measurements made with this detector, which works at room temperature. Uranium enrichment measurements performed in the field is of special interest at nuclear fuel cycle facilities. Typical applications include quality control, U-235 inventory verification and nuclear safeguards. The Safeguards Laboratory of the Brazilian Nuclear Energy Commission (CNEN) and the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) have initiated the evaluation of the performance of a LaBr3 probe model BrilLanceCe 380 (B380) for U-235 enrichment determination in uranium compounds typically found in nuclear facilities under safeguards. This activity is routinely performed by national and international safeguards inspectors in both Brazilian and Argentine facilities. Depending on the characteristics of the material to be verified and the conditions at the measurement location, NaI or high-purity germanium detector (HPGe) are usually selected as the standard gamma-ray spectroscopic system for enrichment determination. This paper presents the conclusions of the initial studies jointly conducted by CNEN and ABACC regarding the use of a LaBr3 detector for enrichment determination, based on the comparison with NaI and HPGe typical performances. It also discusses the possibility to use this new gamma-ray detector as a standard technique for safeguards applications, compliant with national and international performance values. (author)

  16. The killing of African trypanosomes by ethidium bromide.

    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.

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

    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

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

    J. Liao

    2011-09-01

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

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

    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...

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

    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

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

    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

  2. Bromide and iodide removal from waters under dynamic conditions by Ag-doped aerogels.

    Sánchez-Polo, M; Rivera-Utrilla, J; von Gunten, U

    2007-02-01

    The objective of this study was to analyze the efficiency of Ag-doped aerogels in the removal of bromide and iodide from water. To test the applicability of these aerogels in water treatment, adsorption of bromide and iodide was studied under dynamic conditions using waters from Lake Zurich and a mineral water. The results obtained by using these waters showed a high breakthrough volume (V(0.02)=0.4 L) of the columns, while the height of the mass transfer zone (H(MTZ)=6.8 cm) was low, regardless of the anion under study. Bromide- and iodide-saturated columns were regenerated with NH4OH. No change in the column characteristics was observed after two regeneration treatments, regardless of the type of water considered. PMID:17109877

  3. Skin injuries afflicting three oil workers following contact with calcium bromide and/or calcium chloride.

    Saeed, W R; Distante, S; Holmes, J D; Kolhe, P S

    1997-01-01

    Calcium bromide brine is a highly concentrated aqueous solution of calcium bromide and calcium chloride. It is used extensively in the oil industry. This solution and its components are recognized as causes of skin injury and information is available from the manufacturers on their safe use and handling. Two patients who were injured following unprotected skin exposure to this solution and one patient who was injured following exposure to calcium chloride powder are reported. All sustained skin injuries characterised by an absence of pain and a delayed clinical appearance of the full extent of the injury. Furthermore healing was complicated by graft loss or was slow. Although organic bromine compounds are recognized as a cause of skin injuries, no previous reports of such injuries to humans secondary to calcium chloride or bromide exposure were found in the medical literature. Our experience with these patients is described. PMID:9568340

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

    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.

  5. Characterization of cyanogen bromide peptides of hypoxanthine phosphoribosyltransferase by a micromethod

    Human hypoxanthine phosphoribosyltransferase (HPRT-EC 2.4.2.8), either from erythrocytes labeled in vitro with 125I or from HeLa cells labeled in vivo with [3H]leucine, [3H]lysine, or [3H]arginine, was cleaved with cyanogen bromide. All four labeled enzymes produced cyanogen bromide peptides with molecular weights of 7800, 5600, 4100, 2500, and 1300 which were separated by sodium dodecyl sulfate urea polyacrylamide gel electrophoresis. Experiments with [35S]methionine-labeled HPRT indicated that 88 to 94% of the 35S label was released by the cyanogen bromide reaction. The relative distribution of radioactivity in each of the tritiated peptides indicates that there are 20 leucines, 15 lysines, and 12 arginines per enzyme subunit

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

    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

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

    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

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

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

    2011-02-21

    As an alternative to the partial oxidation of methane to synthesis gas followed by methanol synthesis and the subsequent generation of olefins, we have studied the production of light olefins (ethylene and propylene) from the reaction of methyl bromide over various modified microporous silico-aluminophosphate molecular-sieve catalysts with an emphasis on SAPO-34. Some comparisons of methyl halides and methanol as reaction intermediates in their conversion to olefins are presented. Increasing the ratio of Si/Al and incorporation of Co into the catalyst framework improved the methyl bromide yield of light olefins over that obtained using standard SAPO-34. PMID:21203621

  9. Kinetics of bromide catalysed oxidation of dextrose by cerium (IV) in aqueous sulphuric acid solution

    Kinetics of bromide catalysed oxidation of dextrose by CeIV in aqueous sulphuric acid medium show first order dependence each in dextrose and cerium(IV). The reaction rate decreases on increasing the concentration of hydrogen ion. The increase in [HSO4-] or [SO42-] decreases the rate. The bromide ion shows positive catalytic effect on the reaction rate. The value of activation energy has been calculated and a suitable mechanism confirming to the kinetic data is proposed. (author). 3 refs., 3 tabs

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

    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

  11. Photochemical reactions involving nitrosylpentacyanoferrate (II) - bromide system using cadmium sulphide as semiconductor

    Sodium nitroprusside contains cyanide ligands that are not easily replaced chemically. An effort has been made to substitute this ligand by another anionic ligand like bromide. The rate of this photochemical reaction has been observed spectrophotometrically in the presence of cadmium sulphide as a semiconductor. The effect of different parameters like pH, intensity of light, concentration of sodium nitroprusside and bromide ion on the rate of this substitution reaction has been studied. The product was isolated and characterized by different analytical methods. A tentative mechanism for this photochemical substitution has been proposed. (Author)

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

    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...

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

    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.

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

    Everson, Daniel A.; Jones, Brittany A.; Weix, Daniel J.

    2012-01-01

    A general method is presented for the synthesis of alkylated arenes by the chemoselective combination of two electrophilic carbons. Under the optimized conditions, a variety of aryl and vinyl bromides are reductively coupled with alkyl bromides in high yields. Under similar conditions, activated aryl chlorides can also be coupled with bromoalkanes. The protocols are highly functional-group tolerant (−OH, −NHTs, −OAc, −OTs, −OTf, −COMe, −NHBoc, −NHCbz, −CN, −SO2Me), and the reactions are assem...

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

    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...

  16. Nickel-catalyzed Kumada cross-coupling reactions of tertiary alkylmagnesium halides and aryl bromides/triflates.

    Joshi-Pangu, Amruta; Wang, Chao-Yuan; Biscoe, Mark R

    2011-06-01

    We report a Ni-catalyzed process for the cross-coupling of tertiary alkyl nucleophiles and aryl bromides. This process is extremely general for a wide range of electrophiles and generally occurs with a ratio of retention to isomerization >30:1. The same procedure also accommodates the use of aryl triflates, vinyl chlorides, and vinyl bromides as the electrophilic component. PMID:21553878

  17. Molecular structure of the complex of octano-8-lactam with magnesium bromide

    Kříž, Jaroslav; Dybal, Jiří; Kurková, Dana; Prokopová, I.; Hroch, Z.

    2001-01-01

    Roč. 202, č. 17 (2001), s. 3371-3378. ISSN 1022-1352 R&D Projects: GA AV ČR KSK2050602; GA ČR GA106/98/0699 Institutional research plan: CEZ:AV0Z4050913 Keywords : anionic polymerization * coordination * magnesium bromide Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.629, year: 2001

  18. Microwave-Enhanced Cross-Coupling Reactions Involving Alkynyltrifluoroborates with Aryl Bromides

    George W. Kabalka

    2013-01-01

    Full Text Available Palladium-catalyzed alkynylation has emerged as one of the most reliable methods for the synthesis of alkynes which are often used in natural product syntheses and material science. An efficient method for coupling alkynyltrifluoroborates with various aryl bromides in the presence of a palladium catalyst has been developed using microwave irradiation. The microwave reactions are rapid and efficient.

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

    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...

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

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

    2016-04-01

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

  1. Iodine transfer through mother´s milk: the influence of bromide

    Pavelka, Stanislav

    Oxford : Academic Press, 2009 - (Preedy, V.; Burrow, G.; Watson, R.), s. 199-206 ISBN 978-0-12-374135-6 Grant ostatní: EC(XE) LSHG-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * iodine * mother’s milk Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

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

    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)

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

    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...

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

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

    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

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

    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. Hydrophobic Ion-Pairing of Low Molecular Weight Heparin with Cetyltrimethylammonium Bromide

    Nermin E. Eleraky; Mohamed, Dina F; Mohamed A. Attia; Pauletti, Giovanni M.

    2015-01-01

    Purpose: Unfavorable physicochemical properties of low molecular weight heparin (LMWH) restrict membrane permeation of this therapeutic macromolecule to paracellular passive diffusion. To augment LMWH flux across biological membranes using contributions of transcellular transport mechanisms, this study explored formation of electrostatically stabilized association complexes via ion-pairing with the lipophilic cetyltrimethylammonium bromide (CTAB). Methods: LMWH/CTAB interactions were assessed...

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

    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.

  9. The stereoselective synthesis of dienes through dehalogenative homocoupling of terminal alkenyl bromides on Cu(110).

    Sun, Qiang; Cai, Liangliang; Ma, Honghong; Yuan, Chunxue; Xu, Wei

    2016-05-21

    We have successfully achieved the stereoselective synthesis of a specific cis-diene moiety through a dehalogenative homocoupling of alkenyl bromides on the Cu(110) surface, where the formation of a cis-form organometallic intermediate is the key to such a stereoselectivity as determined by DFT calculations. PMID:27063567

  10. Combinatorial electrochemistry using metal nanoparticles: from proof-of-concept to practical realisation for bromide detection.

    Sljukić, Biljana; Baron, Ronan; Salter, Chris; Crossley, Alison; Compton, Richard G

    2007-05-01

    Principles and practical application of combinatorial electrochemistry in search for new electroactive materials in electroanalysis have been explored. Nanoparticles of three different metals: silver, gold and palladium have been independently synthesized on the glassy carbon spherical powder surface by electroless deposition process and characterized using both spectroscopic and electrochemical techniques. These three materials were then combined together onto basal plane pyrolytic graphite electrode surface and the application of the combinatorial approach to find the electrode material for bromide detection as model target analyte was demonstrated. The component electroactive for bromide detection was next identified and it was found that silver nanoparticles were the active ones. A composite electrode based on silver nanoparticle modified glassy carbon powder and epoxy resin was then fabricated and it was found to allow accurate determination of bromide. The electroactivity for the bromide determination of the composite electrode was compared with that of a bulk silver electrode and it was shown that the composite electrode is very efficient with a comparable electroactivity with only a portion of precious metals being used for its construction. PMID:17416224

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

    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...

  12. Once-daily glycopyrronium bromide, a long-acting muscarinic antagonist, for chronic obstructive pulmonary disease

    Ulrik, Charlotte Suppli

    2012-01-01

    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 nove...

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

    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...

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

    Pavelka, Stanislav

    2012-01-01

    Roč. 291, č. 2 (2012), s. 379-383. ISSN 0236-5731 R&D Projects: GA ČR(CZ) GA304/08/0256 Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * goitrogenic effect * iodine radionuclides * thyroid hormone Subject RIV: ED - Physiology Impact factor: 1.467, year: 2012

  15. Radioiodine tracers as useful tools in studies of thyrotoxic effects of exogenous bromide and perchlorate ions

    Pavelka, Stanislav

    2012-01-01

    Roč. 291, č. 2 (2012), s. 405-408. ISSN 0236-5731 R&D Projects: GA ČR(CZ) GA304/08/0256 Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * perchlorate * radioiodine tracer * thyroid hormone Subject RIV: ED - Physiology Impact factor: 1.467, year: 2012

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

    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...

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

    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

  18. Removal of bromide and iodide anions from drinking water by silver-activated carbon aerogels.

    Sánchez-Polo, M; Rivera-Utrilla, J; Salhi, E; von Gunten, U

    2006-08-01

    The aim of this study is to analyze the use of Ag-doped activated carbon aerogels for bromide and iodide removal from drinking water and to study how the activation of Ag-doped aerogels affects their behavior. It has been observed that the carbonization treatment and activation process of Ag-doped aerogels increased the surface area value ( [Formula: see text] ), whereas the volume of meso-(V(2)) and macropores (V(3)) decreased slightly. Chemical characterization of the materials revealed that carbonization and especially activation process considerably increased the surface basicity of the sample. Original sample (A) presented acidic surface properties (pH(PZC)=4.5) with 21% surface oxygen, whereas the sample that underwent activation showed mainly basic surface chemical properties (pH(PZC)=9.5) with only 6% of surface oxygen. Carbonization and especially, activation process considerable increased the adsorption capacity of bromide and iodide ions. This would mainly be produced by (i) an increase in the microporosity of the sample, which increases Ag-adsorption sites available to halide anions, and (ii) a rise of the basicity of the sample, which produces an increase in attractive electrostatic interactions between the aerogel surface, positively charged at the working pH (pH(solution)water treatment, adsorption of bromide and iodide was studied under dynamic conditions using waters from Lake Zurich. Results obtained showed that the carbonization and activation processes increased the adsorptive capacity of the aerogel sample. However, results showed that the adsorption capacity of the aerogel samples studied was considerably lower in water from Lake Zurich. Results showed X(0.02) (amount adsorbed to initial breakthrough) values of 0.1 and 4.3 mg/g for chloride anion and dissolved organic carbon (DOC), respectively, during bromide adsorption process in water from Lake Zurich. This indicates that the adsorptive capacity reduction observed may be due to (i) blocking

  19. Suppression of IL-8 production from airway cells by tiotropium bromide in vitro

    Suzaki I

    2011-09-01

    Full Text Available Isao Suzaki1, Kazuhito Asano2, Yusuke Shikama3, Taisuke Hamasaki1, Ayako Kanei1, Harumi Suzaki11Department of Otorhinolaryngology, School of Medicine, Showa University, Tokyo, Japan; 2Division of Physiology, School of Nursing and Rehabilitation Sciences, Showa University, Yokohama, Japan; 3Department of Respiratory Diseases, Showa University Northern Yokohama Hospital, Yokohama, JapanBackground: COPD is characterized by persistent and progressive airway inflammation. Although neutrophilic airway inflammation is generally accepted to be a major factor in the pathogenesis of COPD, the influence of the agents used for the treatment of COPD on neutrophil functions such as chemotaxis is not fully understood.Purpose: The present study aimed to examine the influence of tiotropium bromide on the production of interleukin (IL-8 from human airway epithelial cells and lung fibroblasts (LFs after lipopolysaccharide (LPS stimulation in vitro.Methods: BEAS-2B cells, human bronchial epithelial cell line, and LFs, at a concentration of 5 × 105 cells/mL, were stimulated with LPS in the presence of various concentrations of tiotropium bromide. IL-8 in culture supernatants was examined by enzyme-linked immunosorbent assay (ELISA. IL-8 messenger ribonucleic acid (mRNA expression was examined by real-time polymerase chain reaction. The influence of tiotropium bromide on LPS-induced signaling pathways was also analyzed by examining nuclear factor-kappa (NF-κB activation and signaling protein phosphorylation by ELISA.Results: Tiotropium bromide at >15 pg/mL inhibited IL-8 production from both BEAS-2B cells and LFs after LPS stimulation. Tiotropium bromide also suppressed IL-8 mRNA expression through the inhibition of NF-κB activation and signaling protein, extracellular-signal-regulated kinase 1/2, and c-Jun N-terminal kinase, phosphorylation.Conclusion: The present results strongly suggest that tiotropium bromide exerts the inhibitory effect on neutrophilic

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

    J. Liao

    2012-02-01

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

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

    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

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

    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)

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

    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

  4. Cobalt-Catalyzed Cross-Coupling of Grignards with Allylic and Vinylic Bromides: Use of Sarcosine as a Natural Ligand.

    Frlan, Rok; Sova, Matej; Gobec, Stanislav; Stavber, Gaj; Časar, Zdenko

    2015-08-01

    Sarcosine was discovered to be an excellent ligand for cobalt-catalyzed carbon-carbon cross-coupling of Grignard reagents with allylic and vinylic bromides. The Co(II)/sarcosine catalytic system is shown to perform efficiently when phenyl and benzyl Grignards are coupled with alkenyl bromides. Notably, previously unachievable Co-catalyzed coupling of allylic bromides with Grignards to linearly coupled α-products was also realized with Co(II)/sarcosine catalyst. This method was used for efficient preparation of the key intermediate in an alternative synthesis of the antihyperglycemic drug sitagliptin. PMID:26158563

  5. Thorium electrode potentials in equimolar melt of potassium and sodium bromides

    The equilibrium electrode potentials of thorium in an equimolar mixture of potassium and sodium bromides are measured for 700, 800 and 900 deg C within the concentration range from 0.3 to 3.0 molar %. Th. The bi - and tetravalent ions are found to dominate in equilibrium with the metal. Temperature dependence of the equilibrium constant of reaction Th(solid) + Th4+(melt) reversible 2 Th2+(melt) is obtained and the conventional standard thorium electrode potentials with respect to its bi - and tetravalent ions are measured. Upon replacement of chlorine aniones by bromine ones the reaction shifted to the right hand side. Experimental data enabled to estimate the thermodynamics of mixing liquid thorium tetrabromide with the melted mixture of potassium and sodium bromides

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

    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)

  7. Plasma fluoride and bromide concentrations during occupational exposure to enflurane or halothane

    Carlsson, P.; Ekstrand, J.; Hallen, B.

    1985-10-01

    The plasma fluoride and bromide concentrations were studied in operating theatre personnel. When enflurane was used, the increase in plasma fluoride concentration could not be distinguished from normal individual variations, but the plasma bromide concentration increased significantly when halothane was used. Seven patients were exposed to enflurane in a concentration of 200 parts per million for 4 h. A significant increase in the plasma concentration of fluoride was observed. The peak concentrations of fluoride occurred during exposure and the increase lasted less than 12 h. The increase in fluoride concentration was larger at this trace concentration than reported after anesthetic concentrations. Cerebrospinal fluid (CSF) fluoride concentration was also studied; a smaller and delayed increase was found in CSF compared to plasma.

  8. Study of the corrosion resistance of metals in a lithium bromide solution

    Mel' nik, V.V.; Spivak, R.Sh.; Sokolov, V.V.; Trofimenko, A.G.

    1988-07-01

    Results are reported of a study of the corrosion resistance of the stainless steels 12Kh19N10T, 10Kh17N13M3T, 08Kh17N15M3T, 10Kh21N6M2T, and 06KhI28MDT, cupronickel MNZhMts 30-1-1, nickel NP-2, and titanium alloys VT1-0, PT-1M, and PT-3V in a solution of lithium bromide for purposes of assessing these alloys for use in absorption-type refrigerating units using the bromide as an absorbent. The uniform corrosion rate was determined from the weight loss; the nonuniform corrosion rate was determined by measuring the maximum depth of the pits under a microscope. Results are comparatively evaluated.

  9. Study of the isotope effect in hydrogen exchange reactions in liquid hydrogen bromide and liquid ammonia

    The subject of the investigation was the thermodynamic isotope effects in naphthalene-hydrogen bromide and benzene-ammonia systems in the presence of potassium amide acting as a catalyst. Protium, deuterium and tritium atoms were present in the system during the experiments. In the experiments on direct and ''reverse'' exchange, the kinetic isotope effects of hydrogen were measured in the liquid-phase systems hydrogen bromide-diphenvl and benzene-ammonia. The mechanisms of exchange reactions of aromatic hydrocarbons with HBr and NH3 are considered with regard to the findings of kinetic experiments. There is a brief description of the methods of preparation in which deuterized and tritiated compounds are used. For tritium counting a scintillation coincidence system was used; and spectroscopic and mass spectrometric methods were used for the isotopic analysis of deuterized substances. (author)

  10. Apparent molal volumes of symmetrical and asymmetrical isomers of tetrabutylammonium bromide in water at several temperatures

    Highlights: • Apparent molal volumes of five isomers of Bu4NBr in water have been measured. • The structural effect of branched and linear chains is discussed. • The structural contributions to the ionic volume were calculated. -- Abstract: Apparent molal volumes of a series of differently substituted quaternary ammonium bromides, namely tetra-iso-butyl-, tetra-sec-butyl-, tetra-n-butyl-, di-n-butyl-di-sec-butyl- and di-n-butyl-di-iso-butylammonium bromide have been determined as a function of molal concentration at (298.15, 303.15 and 308.15) K. Partial molar volumes at infinite dilution and ionic molar volumes of these quaternary ammonium cations were determined. Structural volume contributions to the ionic molar volume were also calculated. The symmetric and asymmetric quaternary ammonium cations are “structure making” ions. The contribution of the branched butyl chains predominates over the linear butyl chains in the asymmetric cations

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

    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.

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

    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

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

    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.

  14. The Challenge of Research and Extension to Define and Implement Alternatives to Methyl Bromide

    Noling, J. W.; Becker, J. O.

    1994-01-01

    Over the past 30 years, methyl bromide (MBr), a broad spectrum fumigant, has been used extensively for soilborne disease and pest control in the production of many fruit, vegetable, turf, and nursery crops. Recently, agricultural emissions of MBr were implicated as a potentially significant contributor to stratospheric ozone depletion. As a precautionary measure for global ozone protection, the U.S. Environmental Protection Agency has enforced federal legislation which mandates a complete pha...

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

    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...

  16. Ethidium Bromide MIC Screening for Enhanced Efflux Pump Gene Expression or Efflux Activity in Staphylococcus aureus▿

    Patel, Diixa; Kosmidis, Christos; Seo, Susan M.; Kaatz, Glenn W.

    2010-01-01

    Multidrug resistance efflux pumps contribute to antimicrobial and biocide resistance in Staphylococcus aureus. The detection of strains capable of efflux is time-consuming and labor-intensive using currently available techniques. A simple and inexpensive method to identify such strains is needed. Ethidium bromide is a substrate for all but one of the characterized S. aureus multidrug-resistant (MDR) efflux pumps (NorC), leading us to examine the utility of simple broth microtiter MIC determin...

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

    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...

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

    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.

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

    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...

  20. Matrix Metalloproteinase-9 and -2 Expression in the Olfactory Bulb Following Methyl Bromide Gas Exposure

    Bakos, Stephen R.; Schwob, James E.; Costanzo, Richard M.

    2010-01-01

    Matrix metalloproteinase-9 (MMP-9) and MMP-2 are important for recovery following direct traumatic injury within the central nervous system (CNS). However, most CNS injury models include both direct trauma and neuronal deafferentation. This limits the ability to determine if these MMPs are important to one or both components of injury. To establish if MMPs play a role in the deafferentation processes, we investigated MMP-9 and MMP-2 in the olfactory bulb following methyl bromide gas exposure....

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

    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.

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

    Mitchell, Mark A.; Lowrey, Nikki M.

    2012-01-01

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

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

    Xie, T.; Ho, SL; Ma, OCK

    1997-01-01

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

  4. Use of Br-82 and I-131 radionuclides in studies of thyrotoxic effects of exogenous bromide

    Pavelka, Stanislav

    Vol.3. Kolkata: Saha Institute of Nuclear Physics, 2010 - (Lahiri, S.; Maiti, M.; Das, S.), s. 342-344 ISSN 0973-256X. [Application of Radiotracers in Chemical, Environmental and Biological Sciences. Kolkata (IN), 07.11.2010-13.11.2010] R&D Projects: GA ČR(CZ) GA304/08/0256 Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * metabolism of iodine * thyrotoxic Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  5. Interference of exogenous bromide with the metabolism of thyroid hormones in the rat

    Pavelka, Stanislav

    České Budějovice: -, 2008. s. 205-205. ISBN 80-86313-21-2. [Biochemický sjezd /21./. 14.09.2008-17.09.2008, České Budějovice] Grant ostatní: GA AV ČR(CZ) KJB401630701 Institutional research plan: CEZ:AV0Z50110509 Keywords : spo2 * bromide * metabolism * thyroid hormone Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  6. Radiometric quantification of thyrotoxic and goitrogenic effects of exogenous bromide and perchlorate ions

    Pavelka, Stanislav

    Bratislava: Slovenská technická univerzita, 2012, s. 152-156. ISBN 978-80-227-3722-7. [Priemyselná toxikológia 2012 /32./. Svit, Vysoké Tatry (SK), 20.06.2012-22.06.2012] R&D Projects: GA ČR(CZ) GA304/08/0256 Institutional research plan: CEZ:AV0Z50110509 Keywords : bromide * perchlorate * radiometric assay * thyroid peroxidase Subject RIV: ED - Physiology

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

    Zhiling Cao

    2013-12-01

    Full Text Available 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.

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

    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...

  9. Tryptophan modification by 2-hydroxy-5-nitrobenzyl bromide studied by MALDI-TOF mass spectrometry

    Strohalm, M.; Kodíček, M.; Pechar, Michal

    2003-01-01

    Roč. 312, č. 3 (2003), s. 811-816. ISSN 0006-291X R&D Projects: GA ČR GA203/02/0922; GA AV ČR KSK4055109 Institutional research plan: CEZ:AV0Z4050913 Keywords : MALDI-TOF mass spectrometry * 2-hydroxy-5-nitrobenzyl bromide * Koshland reagent Subject RIV: CE - Biochemistry Impact factor: 2.836, year: 2003

  10. Replacing conventional carbon nucleophiles with electrophiles: nickel-catalyzed reductive alkylation of aryl bromides and chlorides.

    Everson, Daniel A; Jones, Brittany A; Weix, Daniel J

    2012-04-11

    A general method is presented for the synthesis of alkylated arenes by the chemoselective combination of two electrophilic carbons. Under the optimized conditions, a variety of aryl and vinyl bromides are reductively coupled with alkyl bromides in high yields. Under similar conditions, activated aryl chlorides can also be coupled with bromoalkanes. The protocols are highly functional-group tolerant (-OH, -NHTs, -OAc, -OTs, -OTf, -COMe, -NHBoc, -NHCbz, -CN, -SO(2)Me), and the reactions are assembled on the benchtop with no special precautions to exclude air or moisture. The reaction displays different chemoselectivity than conventional cross-coupling reactions, such as the Suzuki-Miyaura, Stille, and Hiyama-Denmark reactions. Substrates bearing both an electrophilic and nucleophilic carbon result in selective coupling at the electrophilic carbon (R-X) and no reaction at the nucleophilic carbon (R-[M]) for organoboron (-Bpin), organotin (-SnMe(3)), and organosilicon (-SiMe(2)OH) containing organic halides (X-R-[M]). A Hammett study showed a linear correlation of σ and σ(-) parameters with the relative rate of reaction of substituted aryl bromides with bromoalkanes. The small ρ values for these correlations (1.2-1.7) indicate that oxidative addition of the bromoarene is not the turnover-frequency determining step. The rate of reaction has a positive dependence on the concentration of alkyl bromide and catalyst, no dependence upon the amount of zinc (reducing agent), and an inverse dependence upon aryl halide concentration. These results and studies with an organic reductant (TDAE) argue against the intermediacy of organozinc reagents. PMID:22463689

  11. Ethidium Bromide MIC Screening for Enhanced Efflux Pump Gene Expression or Efflux Activity in Staphylococcus aureus▿

    Patel, Diixa; Kosmidis, Christos; Seo, Susan M.; Kaatz, Glenn W.

    2010-01-01

    Multidrug resistance efflux pumps contribute to antimicrobial and biocide resistance in Staphylococcus aureus. The detection of strains capable of efflux is time-consuming and labor-intensive using currently available techniques. A simple and inexpensive method to identify such strains is needed. Ethidium bromide is a substrate for all but one of the characterized S. aureus multidrug-resistant (MDR) efflux pumps (NorC), leading us to examine the utility of simple broth microtiter MIC determinations using this compound in identifying efflux-proficient strains. Quantitative reverse transcription-PCR identified the increased expression of one or more MDR efflux pump genes in 151/309 clinical strains (49%). Ethidium bromide MIC testing was insensitive (48%) but specific (92%) in identifying strains with gene overexpression, but it was highly sensitive (95%) and specific (99%) in identifying strains capable of ethidium efflux. The increased expression of norA with or without other genes was most commonly associated with efflux, and in the majority of cases that efflux was inhibited by reserpine. Ethidium bromide MIC testing is a simple and straightforward method to identify effluxing strains and can provide accurate predictions of efflux prevalence in large strain sets in a short period of time. PMID:20855743

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

    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.

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

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

    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.

  15. Preparation and optical characteristics of layered perovskite-type lead-bromide-incorporated azobenzene chromophores

    Sasai, Ryo, E-mail: rsasai@riko.shimane-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, F3-3(250), Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Shinomura, Hisashi [Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, F3-3(250), Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-02-15

    Lead bromide-based layered perovskite powders with azobenzene derivatives were prepared by a homogeneous precipitation method. From the diffuse reflectance (DR) and photoluminescence (PL) spectra of the hybrid powder materials, the present hybrids exhibited sharp absorption and PL peaks originating from excitons produced in the PbBr{sub 4}{sup 2-} layer. When the present hybrid powder was irradiated with UV light at 350 nm, the absorption band from the trans-azobenzene chromophore, observed around 350 nm, decreased, while the absorption band from the cis-azobenzene chromophore, observed around 450 nm, increased. These results indicate that azobenzene chromophores in the present hybrid materials exhibit reversible photoisomerization. Moreover, it was found that the PL intensity from the exciton also varied due to photoisomerization of the azobenzene chromophores in the present hybrid. Thus, for the first time we succeeded in preparing the azobenzene derivative lead-bromide-based layered perovskite with photochromism before and after UV light irradiation. - Graphical abstract: For the first time, we succeeded in preparing the azobenzene derivative lead-bromide-based layered perovskite with photochromism before and after UV light irradiation. Highlights: Black-Right-Pointing-Pointer PbBr-based layered perovskite with azobenezene derivatives could be synthesized by a homogeneous precipitation method. Black-Right-Pointing-Pointer Azobenzene derivatives incorporated the present hybrid that exhibited reversible photoisomerization under UV and/or visible light irradiation. Black-Right-Pointing-Pointer PL property of the present hybrid could also be varied by photoisomerization.

  16. Preparation and optical characteristics of layered perovskite-type lead-bromide-incorporated azobenzene chromophores

    Lead bromide-based layered perovskite powders with azobenzene derivatives were prepared by a homogeneous precipitation method. From the diffuse reflectance (DR) and photoluminescence (PL) spectra of the hybrid powder materials, the present hybrids exhibited sharp absorption and PL peaks originating from excitons produced in the PbBr42− layer. When the present hybrid powder was irradiated with UV light at 350 nm, the absorption band from the trans-azobenzene chromophore, observed around 350 nm, decreased, while the absorption band from the cis-azobenzene chromophore, observed around 450 nm, increased. These results indicate that azobenzene chromophores in the present hybrid materials exhibit reversible photoisomerization. Moreover, it was found that the PL intensity from the exciton also varied due to photoisomerization of the azobenzene chromophores in the present hybrid. Thus, for the first time we succeeded in preparing the azobenzene derivative lead-bromide-based layered perovskite with photochromism before and after UV light irradiation. - Graphical abstract: For the first time, we succeeded in preparing the azobenzene derivative lead-bromide-based layered perovskite with photochromism before and after UV light irradiation. Highlights: ► PbBr-based layered perovskite with azobenezene derivatives could be synthesized by a homogeneous precipitation method. ► Azobenzene derivatives incorporated the present hybrid that exhibited reversible photoisomerization under UV and/or visible light irradiation. ► PL property of the present hybrid could also be varied by photoisomerization.

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

    Koumbourlis, Anastassios C; Mastropietro, Christopher

    2015-01-01

    To present the case of a patient with persistent bronchospasm, refractory to treatment with β2-agonists, that resolved promptly with continuous inhalation of large dose (1000 mcg/hr) ipratropium bromide, and to discuss the possibility of tolerance to β2-agonists as the cause for his failure to respond to adrenergic medications. The patient had received multiple doses of albuterol, as well as subcutaneous terbutaline (0.3 mg), intravenous magnesium sulfate (1 g) and intravenous dexamethasone (10 mg) prior to his admission to the intensive care unit. He remained symptomatic despite systemic intravenous steroids, continuous intravenous terbutaline (up to 0.6 mcg/kg/min), and continuous nebulized albuterol (up to 20 mg/hr for 57 hr) followed by 49 hours of continuous levalbuterol (7 mg/hr). Due to the lack of response, all β2-agonists were discontinued at 106 hours post-admission, and he was started on large dose ipratropium bromide (1000 mcg/hr) by continuous nebulization. Clinical improvement was evident within 1 hour and complete resolution of his symptoms within 4 hours. Continuous inhalation of large dose ipratropium bromide may be an effective regimen for the treatment of patients hospitalized with acute asthma who are deemed to be nonresponsive and/or tolerant to β2-agonist therapy. PMID:25859173

  18. Managing opioid-induced constipation in advanced illness: focus on methylnaltrexone bromide

    Katri Elina Clemens

    2010-02-01

    Full Text Available Katri Elina Clemens1,2, Eberhard Klaschik11Department of Science and Research, Centre for Palliative Medicine, University of Bonn, Germany; 2Department of Palliative Medicine and Pain Therapy, Malteser Hospital Bonn/Rhein-Sieg, GermanyAbstract: Constipation is a common symptom in palliative care patients which can generate considerable suffering. There is uncertainty about the choice of treatment options from varying recommendations for management of constipation and a varying clinical practice in palliative care settings. The purpose of the review was to evaluate the current recommendations of therapy guidelines for the management of opioid-induced constipation in palliative care patients with a focus on methylnaltrexone bromide. Recent findings in the literature and related information on the opioid-induced gastrointestinal disorders in patients with advanced illness, as well as information on the opioid-antagonist methylnaltrexone, are discussed. Knowledge of the role of definitions, the causes of constipation and the pathophysiology of opioid-induced constipation must be given high priority in the treatment of patients receiving opioids. Diagnosis and therapy of constipation, therefore, should relate to findings in clinical investigation. Opioid-induced constipation and its adequate treatment is an important issue for patients with advanced illness and also poses therapeutic challenge for clinicians in daily routine. Methylnaltrexone bromide may represent an important therapeutic option for palliative care patients who are suffering from opioid-induced constipation with failure of conventional prophylactic oral laxative treatment.Keywords: opioid-induced constipation, palliative care, opioids, methylnaltrexone bromide

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

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

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

    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.

  1. Electrolytic coloration and spectral properties of hydroxyl-doped potassium bromide single crystals

    Qi, Lan, E-mail: lqipaper@eyou.com [Department of Hydroelectricity, Tianjin University, Tianjin 300072 (China); Song, Cuiying [School of Science, Tianjin University of Commerce, Tianjin 300134 (China); Gu, Hongen [Department of Physics, Tianjin University, Tianjin 300072 (China)

    2013-02-15

    Hydroxyl-doped potassium bromide single crystals are colored electrolytically at various temperatures and voltages by using a pointed cathode and a flat anode. The characteristic OH{sup -} spectral band is observed in absorption spectrum of uncolored single crystal. The characteristic O{sup -}, OH{sup -}, U, V{sub 2}, O{sup 2-}-V{sub a}{sup +}, M{sub L1}, F and M spectral bands are observed simultaneously in absorption spectra of colored single crystals. Current-time curve for electrolytic coloration of hydroxyl-doped potassium bromide single crystal and its relationship with electrolytic coloration processes are given. Production and conversion of color centers are explained. - Highlights: Black-Right-Pointing-Pointer We expanded the traditional electrolysis method. Black-Right-Pointing-Pointer Hydroxyl-doped potassium bromide crystals were colored electrolytically for the first time. Black-Right-Pointing-Pointer Useful V, F and F-aggregate color centers were produced in colored crystals. Black-Right-Pointing-Pointer V color centers were produced directly and F as well as F-aggregate color centers indirectly.

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

    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

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

    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. Reaction of Lithium Diethylamide with an Alkyl Bromide and Alkyl Benzenesulfonate: Origins of Alkylation, Elimination, and Sulfonation

    Gupta, Lekha; Ramírez, Antonio; Collum, David B.

    2010-01-01

    A combination of NMR, kinetic, and computational methods are used to examine reactions of lithium diethylamide in tetrahydrofuran (THF) with n-dodecyl bromide and n-octyl benzenesulfonate. The alkyl bromide undergoes competitive SN2 substitution and E2 elimination in proportions independent of all concentrations except for a minor medium effect. Rate studies show that both reactions occur via trisolvated-monomer-based transition structures. The alkyl benzenesulfonate undergoes competitive SN2...

  5. To compare the efficacy of Drotaverine hydrochloride and Valethamate bromide in shortening of the first stage of labour

    Sangeeta Raman Jogi

    2015-01-01

    Background: To compare the efficacy of Drotaverine Hydrochloride and Valethamate Bromide in shortening of the first stage of Labor. Drotaverine is more effective in regards of shorten the 1st stage of labor, rate of cervical dilatation with less side effects in compare to Valethamate Bromide. Methods: Two Hundred demographically similes woman with full term pregnancy in active labour were included in the study and divided into two groups viz. First Group: 100 women were given injection...

  6. Nickel-catalyzed vinylation of aryl chlorides and bromides with vinyl ZnBr.MgBrCl.

    Yamamoto, Tetsuya; Yamakawa, Tetsu

    2009-05-01

    The Ni-catalyzed cross-coupling of aryl halides and vinylzinc bromide for the synthesis of styrene derivatives was investigated. Of the catalysts surveyed, the combination of Ni(acac)(2) and Xantphos was found to be the most effective for this cross-coupling. This catalyst could be used in reactions with various aryl bromides and chlorides, including electron-rich aryl chlorides such as chloroanisoles. PMID:19354270

  7. Ethidium bromide-induced demyelination of the sciatic nerve of adult Wistar rats

    Riet-Correa G.

    2002-01-01

    Full Text Available Peripheral nerve ultrastructure was assessed after single or multiple local injections of the intercalating dye ethidium bromide. Thirty-four adult Wistar rats of both sexes were divided into five groups and maintained in a controlled environment with rat chow and water ad libitum throughout the experiment. The experimental animals were injected with 1 µl of 0.1% ethidium bromide in 0.9% saline into the central third of the left sciatic nerve 1 (group 1, 2 (group 2, 4 (group 3, 6 (group 4 or 8 (group 5 times. In groups 2 to 5 the injections were made at 28-day intervals. Control animals received the same amount of 0.9% saline. The animals were killed at different times after injection: group 1 at 7 days (2 rats and 15 days (2 rats; for groups 2, 3, 4 and 5, all rats were killed 10 days after the last injection and the lesions were investigated by light and transmission electron microscopy. In the acute lesions, intoxicated Schwann cells showed a vacuolated cytoplasm and separation of the sheaths from the axon. Myelin sheaths underwent progressive vesiculation and subsequent segmental demyelination. Myelin debris were withdrawn by macrophages and remyelination by Schwann cells was prominent. With the increase in the number of injections collagen fibers also increased in number and progressively enveloped smaller numbers of remyelinated axons composing new fascicles. Wallerian degeneration of fibers apparently not affected by ethidium bromide was more intense in the nerves from groups 4 and 5. The peripheral nerve repairs itself after demyelinating challenges with a profusion of collagen fibers and new fasciculations. This experimental model is valid to mimic recurrent demyelinating neuropathies.

  8. Aerodynamic measurements of methyl bromide volatilization from tarped and nontarped fields

    Methyl bromide (MeBr) is used extensively in agriculture as a soil fumigant and there is growing concern over the role it may play in the depletion of stratospheric ozone. Methyl bromide is applied using various techniques and very little is known about how much of the applied fumigant volatilizes into the atmosphere after the application. The field study was designed to estimate the post-application methyl bromide volatilization loss rates from two different application practices. The fields were approximately 6 km apart in Monterey County, California, and were treated in conformity with local practices as of 1992. The MeBr was injected at a depth of 25 to 30 cm. One field was covered simultaneously with a high-barrier plastic film tarp during the application, and the other was left uncovered, but the furrows made by the injection shanks were bedded over. Volatilization fluxes were estimated using an aerodynamic-gradient technique immediately following the completion of the application process and continued for 9 d for the tarped field and 6 d for the nontarped field. The cumulative volatilization losses from the tarped field were 22% of the nominal application within the first 5 d of the experiment and about 32% of the nominal application within 9 d including the one day after the tarp was removed on Day 8 after application. In contrast, the nontarped field lost 89% of the nominal application by volatilization in 5 d. The volatilization rate from the tarped field was shown to be significantly lower than the nontarped field at a 95% confidence level

  9. On the Mechanism of Electrochemical Reduction of Dodecylpyridinium Bromide in Aprotic Media. An Impedance Study

    Hromadová, Magdaléna; Kolivoška, Viliam; Pospíšil, Lubomír

    Ústí nad Labem: BEST servis, 2010 - (Navrátil, T.; Barek, J.), s. 77-79 ISBN 978-80-254-6710-7. [Modern Electroanalytical Methods /30./. Jetřichovice (CZ), 24.05.2010-28.05.2010] R&D Projects: GA ČR GA203/08/1157; GA ČR GA203/09/0705; GA AV ČR IAA400400802 Institutional research plan: CEZ:AV0Z40400503 Keywords : dodecylpyridinium bromide * reduction mechanism * impendance spectroscopy Subject RIV: CG - Electrochemistry

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

    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.

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

    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)

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

    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...

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

    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.

  14. Temporal and spatial variation in methyl bromide emissions from a salt marsh

    Drewer, Julia; Heal, Mathew R; Heal, Kate V; Smith, Keith A

    2006-01-01

    Methyl bromide (CH3Br) is a trace gas involved in stratospheric ozone depletion with both anthropogenic and natural sources. Estimates of natural source strengths are highly uncertain. In this study, >320 highly temporally and spatially resolved measurements of CH3Br emissions from a salt marsh in Scotland (56°00′N, 2°35′W) were made during one year using eight static enclosures. Net emissions showed both strong seasonal and diurnal cycles. Day-to-day maxima in emissions were associated with ...

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

    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

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

    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...

  17. Copper(I) Bromide: An Alternative Emitter for Blue-Colored Flame Pyrotechnics.

    Juknelevicius, Dominykas; Karvinen, Eero; Klapötke, Thomas M; Kubilius, Rytis; Ramanavicius, Arunas; Rusan, Magdalena

    2015-10-19

    Copper(I) bromide was evaluated as an alternative emitter for blue flame pyrotechnic compositions. CuBr and CuCl emission spectra were recorded from a butane torch flame and compared. Cu(BrO3 )2 was synthesized and used in pyrotechnic compositions as an oxidizer and the source for the generation of CuBr species. Pyrotechnic compositions, which contained copper and potassium bromates as oxidizers, were optimized for the generation of blue flames. The experimental data, including emission spectra of the flames, chromaticity coordinates, burning rates, luminous intensities, and sensitivity tests, were analyzed and compared. PMID:26471445

  18. Spectrophotometric determination of uranium(VI) with chrome azurol S and benzyldimethyllaurylammonium bromide

    Trace quantities of uranium are often determined by spectrophotometric methods based on the reaction of uranyl ions with triphenylmethane dyes, e.g. with chrome azurol S, eriochrome cyanine R, aluminone, or methyl blue. Sensitivity of the methods in which chrome azurol S was used appeared to be 3x104 l.mol-1.cm-1. We have observed that benzyldimethyllaurylammonium bromide (Sterinol ST) is a good reagent, improving the sensitivity in the U(VI) determination by means of chrome azurol S. Previously we had successfully used this reagent for the determination of trace amounts of Be, Al, In and V(IV). (orig./EF)

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

    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...

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

    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

  1. Methylation of DNA of maize and wheat grains during fumigation with methyl bromide

    The possibility that methylation of DNA occurs during fumigation of foodstuffs with methyl bromide was investigated in two grains, maize and wheat, using 14C-labeled fumigant. 7-Methylguanine and 1-methyladenine were identified as major products along with lesser amounts of 3-methylcytosine and 3-methyladenine. 3-Methylguanine was probably also formed in minor amounts. Although less than 1% of the bound radioactivity was associated with the DNA isolated, the results indicated that 0.5-1% of the guanine residues in the DNA of these grains was methylated during treatment with 48 mg/L methylbromide for 72 h

  2. Raman Spectroscopy Study of the Doping Effect of the Encapsulated Iron, Cobalt, and Nickel Bromides on Single-Walled Carbon Nanotubes

    Marianna V. Kharlamova

    2015-01-01

    In this contribution the modification of the electronic properties of single-walled carbon nanotubes (SWCNTs) filled with nickel bromide, cobalt bromide, and iron bromide was studied by Raman spectroscopy. The doping-induced alterations of the radial breathing mode (RBM) and G-mode in the Raman spectra of the filled SWCNTs were analyzed in detail. The observed shifts of the components of the Raman modes and changes of their profiles allowed concluding that the embedded compounds have an accep...

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

    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. Iodide, bromide, and ammonium in hydraulic fracturing and oil and gas wastewaters: environmental implications.

    Harkness, Jennifer S; Dwyer, Gary S; Warner, Nathaniel R; Parker, Kimberly M; Mitch, William A; Vengosh, Avner

    2015-02-01

    The expansion of unconventional shale gas and hydraulic fracturing has increased the volume of the oil and gas wastewater (OGW) generated in the U.S. Here we demonstrate that OGW from Marcellus and Fayetteville hydraulic fracturing flowback fluids and Appalachian conventional produced waters is characterized by high chloride, bromide, iodide (up to 56 mg/L), and ammonium (up to 420 mg/L). Br/Cl ratios were consistent for all Appalachian brines, which reflect an origin from a common parent brine, while the I/Cl and NH4/Cl ratios varied among brines from different geological formations, reflecting geogenic processes. There were no differences in halides and ammonium concentrations between OGW originating from hydraulic fracturing and conventional oil and gas operations. Analysis of discharged effluents from three brine treatment sites in Pennsylvania and a spill site in West Virginia show elevated levels of halides (iodide up to 28 mg/L) and ammonium (12 to 106 mg/L) that mimic the composition of OGW and mix conservatively in downstream surface waters. Bromide, iodide, and ammonium in surface waters can impact stream ecosystems and promote the formation of toxic brominated-, iodinated-, and nitrogen disinfection byproducts during chlorination at downstream drinking water treatment plants. Our findings indicate that discharge and accidental spills of OGW to waterways pose risks to both human health and the environment. PMID:25587644

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

    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.

  6. Interaction of removal Ethidium Bromide with Carbon Nanotube: Equilibrium and Isotherm studies.

    Moradi, Omid; Norouzi, Mehdi; Fakhri, Ali; Naddafi, Kazem

    2014-01-01

    Drinking water resources may be contaminated with Ethidium Bromide (EtBr) which is commonly used in molecular biology laboratories for DNA identification in electrophoresis. Carbon nanotubes are expected to play an important role in sensing, pollution treatment and separation techniques. In this study adsorption of Ethidium Bromide on single-walled carbon nanotubes (SWCNTs) and carboxylate group functionalized single-walled carbon nanotube (SWCNT-COOH) surfaces have been investigated by UV-vis spectrophotometer. The effect of contact time, initial concentration and temperature were investigated. The adsorbents exhibits high efficiency for EtBr adsorption and equilibrium can be achieved in 6 and 3 min for SWCNTs and SWCNT-COOH, respectively. The effect of temperature on adsorption of EtBr by toward adsorbents shows the process in this research has been endothermic. The results showed that the equilibrium data were well described by the Langmuir isotherm model, with a maximum adsorption capacity of 0.770 and 0.830 mg/g for SWCNTs and SWCNT-COOH, respectively. The adsorption of EtBr on SWCNT-COOH is more than SWCNTs surfaces. A comparison of kinetic models was evaluated for the pseudo first-order, pseudo second-order models. Pseudo second-order was found to agree well with the experimental data. PMID:24401790

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

    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.

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

    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.

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

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

    2015-04-01

    Reactions of calcium bromide with enantiopure and racemic proline in aqueous solution lead to two solids in which the zwitterionic amino acid acts as a bridging ligand between neighbouring cations. Depending on the chirality of the amino acid, topologically very different products are obtained. With racemic proline, bromide acts as a simple uncoordinated counter-anion for the cationic heterochiral chains in catena-poly[[aquacalcium(II)]-μ-aqua-μ3-DL-proline-μ2-DL-proline], {[Ca(C5H9NO2)2(H2O)2]Br2}n. In agreement with chemical intuition, only carboxylate and aqua O atoms coordinate the alkaline earth cation in a low-symmetry arrangement. In contrast, L-proline affords the two-dimensional network poly[dibromidobis(μ2-L-proline)calcium(II)], [CaBr2(C5H9NO2)2]n, with an unexpected CaBr2 unit in a more regular coordination sphere. PMID:25836292

  10. Fusion and Thermal Degradation Behavior of Symmetric Sulfur-Containing Quaternary Ammonium Bromides.

    Huynh, Thai L Y; Poiroux, Kaitlyn; O'Brien, Richard A; West, Kevin N; Davis, James H; West, Christy Wheeler

    2016-02-25

    Quaternary ammonium salts are widely used in consumer products and industrial processes, where their instability at elevated temperatures limits their range of applications. In this work, the thermal behavior of a new class of quaternary ammonium salts was investigated using differential scanning calorimetry. These salts contain a sulfur atom in each chain at the fourth position from the central nitrogen and are thus termed thiaquats. The temperatures at which these salts melt and thermally degrade were determined, and enthalpies and entropies of fusion were evaluated. Their melting points increase with chain lengths, in contrast to the behavior of traditional quaternary ammonium salts. Furthermore, they exhibit enthalpies and entropies of fusion significantly lower than corresponding tetraalkyl analogues. These trends provide physical insight into the molecular-level behavior of these salts, suggesting that they do not fully dissociate upon melting. The thiaquats also exhibit thermal stability to markedly higher temperatures than traditional quaternary ammonium bromides, a phenomenon that can be explained in by strong pairing between the quaternary cation and bromide anion, which inhibits possible decomposition mechanisms. This enhanced thermal stability may enable applications of these salts in processes where traditional salts are not viable, such as phase-transfer-catalyzed systems performed at elevated temperatures. PMID:26849572

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

    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

  12. Titrimetric and spectrophotometric determination of doxycycline hyclate using bromate-bromide, methyl orange and indigo carmine

    Pavagada Jagannathamurthy Ramesh

    2010-07-01

    Full Text Available One titrimetric and two indirect spectrophotometric methods are described for the determination of doxycycline hyclate (DCH in bulk drug and in its formulations. The methods use bromate-bromide, methyl orange and indigo carmine as reagents. In titrimetry (method A, DCH is treated with a known excess of bromate- -bromide mixture in acid medium and the residual bromine is back titrated iodometrically after the reaction between DCH and in situ bromine is ensured to be complete. In spectrophotometric methods, the excess of bromine is estimated by treating with a fixed amount of either methyl orange (method B or indigo carmine (method C and measuring the change in absorbance either at 520 or 610 nm. Titrimetric method is applicable over 1-8 mg range and the calculations are based on a 1:2 (DCH:bromate stoichiometric ratio. In spectrophotometry, the calibration graphs were found to be linear over 0.25-1.25 and 1.0-5.0 μg mL-1 for method B and C, respectively, with corresponding molar absorptivity values of 2.62×105 and 6.97×104 L mol-1 cm-1. The accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of DCH.

  13. Experimental measurements of carbon dioxide solubility in aqueous tetra-n-butylammonium bromide solutions

    Highlights: • We report experimental CO2 solubility data in aqueous tetra-n-butylammonium bromide. • The absolute gravimetric technique was used for the CO2 solubility measurements. • CO2 solubility in pure water agrees with the literature data. - Abstract: In this paper, we report the absolute measurements of CO2 solubility in aqueous tetra-n-butylammonium bromide (TBAB) solution. The measurement range was 0.2 MPa < P < 4 MPa, 286.15 K < T < 298.15 K, with 0 (pure water) < wTBAB < 0.4, where P, T, and wTBAB denote the pressure, temperature, and mass fraction of TBAB in the aqueous feed solutions, respectively. These thermodynamic conditions are outside the hydrate formation region. We evaluated salting-in and -out effects based on the experimental data, and confirmed that the CO2 salting-out effect of TBAB clearly appeared at T = 292 K with wTBAB < 0.32 and the salting-in effect may exist for P > 3 MPa and T > 292 K with wTBAB ⩾ 0.4 mass fraction of TBAB

  14. Study of the Reaction 2-(p-Nitrophenylethyl Bromide + OH− in Dimeric Micellar Solutions

    María Luisa Moyá

    2011-11-01

    Full Text Available The dehydrobromination reaction 2-(p-nitrophenylethyl bromide + OH− was investigated in several alkanediyl-a-w-bis(dodecyldimethylammonium bromide, 12-s-12,2Br− (with s = 2, 3, 4, 5, 6, 8, 10, 12 micellar solutions, in the presence of NaOH 5 × 10−3 M. The kinetic data were quantitatively rationalized within the whole surfactant concentration range by using an equation based on the pseudophase ion-exchange model and taking the variations in the micellar ionization degree caused by the morphological transitions into account. The agreement between the theoretical and the experimental data was good in all the dimeric micellar media studied, except for the 12-2-12,2Br− micellar solutions. In this case, the strong tendency to micellar growth shown by the 12-2-12,2Br− micelles could be responsible for the lack of accordance. Results showed that the dimeric micelles accelerate the reaction more than two orders of magnitude as compared to water.

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

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

    1980-04-10

    Bronchodilator action of two pharmacologically different drugs have been compared. Ipratropium bromide (Sch 1000) is a synthetic atropine derivative and terbutaline sulphate is a beta-stimulating agent. Twelve asthmatic patients and eight patients with chronic bronquitis received terbutaline 0.50 mg. and ipratropium 0.04 mg by aerosol inhalation. Both drugs were given at random on a consecutive-day schedule. All patients were clinically stable before treatment (basal FEV/VC less than 60 percent). Total lung capacity (TLC) forced expiratory volume (FEV), SRaw, and V'/V curves before and at 15, 60, 120, and 240 minutes after the produce administration were registered. Presence of side-effects was also checked. An intensive bronchodilator action was observed either after inhalation of ipratropium bromide or terbutaline, but statistical studies showed no significant differences between both drugs in relation to intensity and duration of their actions. Sch 1000 caused similar bronchodilator effects in all cases; a more intense effect in patients with chronic bronchitis could not be noticed. Evaluation of V'/V curve, and especially its relation to a same pulmonary volume, pointed out that both drugs act upon small respiratory airways. Advance side-effects were not present. PMID:6446008

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

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

    2011-01-01

    Pyridostigmine bromide (PB) is a reversible cholinesterase inhibitor. The aim of this study was to determine the effect of orally administration of single dose sustained-released tablet of pyridostigmine bromide (PBSR) on the frequency domain indices of heart rate variability (HRV). Thirty-two healthy young men were participated in this study. They were divided into 2 groups; the pyridostigmine group (n = 22) and the placebo group (n = 10). Electrocardiogram (ECG) was recorded at 10, 30, 60, 90, 120, 150, 180, 210, 240, 300 and 420 min after PBSR administration. At each time, simultaneously, a blood sample was prepared and PB plasma concentration was measured by high-performance liquid chromatography (HPLC) method. Statistical analysis showed that in different indices of HRV, there is a significant increase in low frequency (LF) band at 300 min, but no difference in high frequency band (HF). It also showed significant decreases in normalized high frequency band (Hfnu), normalized low frequency band (Lfnu) and LF/HF ratio at 120, 240 and 300 min after PBSR administration. Maximum plasma concentration of PB was 150 min after the administration. In conclusion, administration of a single dose PBSR can enhance the frequency domains indices of HRV and improvesympathovagal balance. PMID:24250427

  17. Prolonged release matrix tablet of pyridostigmine bromide: formulation and optimization using statistical methods.

    Bolourchian, Noushin; Rangchian, Maryam; Foroutan, Seyed Mohsen

    2012-07-01

    The aim of this study was to design and optimize a prolonged release matrix formulation of pyridostigmine bromide, an effective drug in myasthenia gravis and poisoning with nerve gas, using hydrophilic - hydrophobic polymers via D-optimal experimental design. HPMC and carnauba wax as retarding agents as well as tricalcium phosphate were used in matrix formulation and considered as independent variables. Tablets were prepared by wet granulation technique and the percentage of drug released at 1 (Y(1)), 4 (Y(2)) and 8 (Y(3)) hours were considered as dependent variables (responses) in this investigation. These experimental responses were best fitted for the cubic, cubic and linear models, respectively. The optimal formulation obtained in this study, consisted of 12.8 % HPMC, 24.4 % carnauba wax and 26.7 % tricalcium phosphate, had a suitable prolonged release behavior followed by Higuchi model in which observed and predicted values were very close. The study revealed that D-optimal design could facilitate the optimization of prolonged release matrix tablet containing pyridostigmine bromide. Accelerated stability studies confirmed that the optimized formulation remains unchanged after exposing in stability conditions for six months. PMID:22713949

  18. Treatment of adult asthma: controlled double-blind clinical trial of oxitropium bromide.

    Taytard, A; Auzerie, J; Vergeret, J; Tozon, N; Freour, P

    1984-01-01

    Sixteen young adult sufferers from extrinsic paroxysmal asthma with pollen hypersensitivity took part in a therapeutic trial of the synthetic anticholinergic agent oxitropium bromide administered by a metered dose inhaler. The study comprised three 3-week periods. The first, run-in period was carried out to confirm the ability of the patients to maintain a daily record of symptoms. During the second and third periods, the patient received 3 X 2 inhalations of drug or placebo in a cross-over design. The medical staff was blind to the nature of the aerosol (drug or placebo), which was given in random order. The run-in clinical score was high. Asymptomatic days were relatively infrequent and daily drug consumption was high. Functional studies between the cross-over periods showed flow-rate values close to normal, with an increase in residual volume and functional residual capacity. During treatment either with placebo or oxitropium, there was a statistically significant decrease in clinical scores. Results for oxitropium bromide treatment were significantly better than the run-in values (p less than 0.005) and the placebo period (p less than 0.02). There was no significant change in non-trial drug consumption. Functional values showed no difference in terms of flow rate, although oxitropium did cause a significant improvement in the RV/TLC ratio (p less than 0.05). No adverse reactions were reported. PMID:6376144

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

    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.

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

    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.)

  1. Comparison of inorganic inhibitors of copper, nickel and copper-nickels in aqueous lithium bromide solution

    The electrochemical behavior of copper, nickel and two copper-nickel (Cu90/Ni10 and Cu70/Ni30) alloys in 850 g/L LiBr solution in the absence and presence of three different inorganic inhibitors (chromate CrO42-, molybdate MoO42-, and tetraborate B4O72-) has been studied. Differences in inhibition efficiency are discussed in terms of potentiodynamic and cyclic measurements. The best protection is obtained by adding chromate to the 850 g/L LiBr solution while the inhibition efficiencies of molybdate and tetraborate ions were not markedly high. Very aggressive anions, such as bromides, in the present experimental conditions, notably reduce the action of the less efficient molecules (molybdate and tetraborate), but not that of the most efficient ones (chromate). The results of the investigation show that the inhibiting properties depend on the nickel content in the alloy; this element improves the general corrosion resistance of the material in the sense that it shifts free corrosion potential towards more noble values and density corrosion currents towards lower levels. The nickel content in the alloy also enlarges the passivating region of the materials in chromate and molybdate-containing solution; furthermore it decreases the current passivating values to lower values. Nickel addition improves the localized corrosion resistance in the bromide media

  2. 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

    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

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

    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.

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

    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...

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

    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.

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

    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

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

    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

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

    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.

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

    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

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

    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

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

    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

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

    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.

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

    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.

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

    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. Bromide removal by hydrotalcite-like compounds in a continuous system.

    Echigo, S; Itoh, S; Kuwahara, M

    2007-01-01

    Bromide ion removal from a real water matrix by hydrortalcite-like compounds (HTCs) was attempted in a column reactor to control the formation of brominated disinfection by-products in drinking water treatment process. The performance of HTCs was found to be comparable to a commercially available ion exchange resin for relatively low alkalinity water. Also, it was deduced that HTCs are better than ion exchange resins for high sulfate water because of their unique ion selectivity. In addition, the ion exchange reactions by HTCs were faster than a commercially available resin. Thus, HTCs are expected to provide similar performance to organic resins without the concern about secondary contamination (i.e., elution of organic compounds from resins). PMID:18057649

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

    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

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

    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.

  18. 2-(4-Methylsulfanylphenyl-1H-benzimidazol-3-ium bromide

    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].

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

    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

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

    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

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

    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. Small Angle Neutron Scattering Studies from Micellar Solutions of Cetyl trimethyl ammonium bromide

    Small Angle Neutron Scattering from 0.1M solution of Cetyl trimethyl ammonium bromide (CTAB) without and with addition of varying concentrations of NaSal and KCl have been studied. It is observed that micelles are ellipsoidal (c=a≠b) and the a/b ratio depends on concentrations of CTAB, NaSal and KCl and on the temperature of the solution. The measured spectra show that on addition of NaSal, two or more of CTAB micelles join together to form together to from bigger micelle. These micelles disintergrate to smaller ones on heating. With the increase of KCl concentrations, the peak broadens without any significant shift in peak position. The broadening of the peak is a result of the reduction in coulomb interaction between the micelles

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

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

    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.

  5. Spectrophotometric determination of microamounts of scandium with o-chlorophenylfluorone and cetyltrimethylammonium bromide.

    Luo, Z M; He, W M

    1990-06-01

    The reaction of scandium(III) with o-chlorophenylfluorone (o-CIPF) in the presence of cetyltrimethylammonium bromide (CTMAB) has been studied. In an acetate buffer at pH 4.4, a red-purple complex is obtained, with maximum absorption at 569 nm and a molar absorptivity of 1.31 x 10(5)1.mole(-1).cm(-1). The composition of the complex is found to be 1:2:2 Sc-o-CIPF-CTMAB. Beer's law is obeyed over the range 0-12 mug/25 ml scandium. The proposed method has been used for determination of trace scandium in tungsten ores after its prior separation by solvent extraction. PMID:18964993

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

    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)

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

    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

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

    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.

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

    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...

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

    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).

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

    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.

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

    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

  13. Study on uranium(VI) biosorption of marine-derived fungus treated by cetyltrimethyl ammonium bromide

    Fusarium sp. ZZF51 was chemically treated by cetyltrimethyl ammonium bromide to explore its potential for the removal of uranium(VI). The experimental results showed that the biosorption capacity and the removal efficiency for the modified mycelium under optimal conditions were 400.10 mg g-1 and 96.02 %, respectively, which were more than those of the native biomass (21.42 mg g-1 and 61.89 %). Lagergren's pseudo-second-order kinetic model and Langumir isotherm model showed the better agreement with the experimental data. SEM experiment indicated the mycelium could provide ready access and rich surface area for uranium binding, and FTIR analysis revealed that hydroxyl, carbonyl, especially for nitrogen groups played important roles in biosorption. (author)

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

    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

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

    Horita N

    2015-04-01

    Full Text Available Nobuyuki Horita, Takeshi Kaneko Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan Abstract: Once-daily dual-bronchodilator therapy with combined indacaterol and glycopyrronium bromide in one device (Ultibro, Breezhaler, often called QVA149, was first approved in 2013 in Japan and Europe. As of November 2014, more than 40 countries had approved this medication except for the USA. This is the first dual bronchodilator in one device. Now, the Breezhaler is the only device that can provide long-acting muscarinic antagonist (glycopyrronium bromide, long-acting beta agonist (indacaterol, and a combination of the two medications (QVA149. The choice among the three medications allows a patient to use the same inhalation device even when the regimen is changed from single-bronchodilator therapy to dual-bronchodilator therapy. In addition, the quick bronchodilation effect and once-daily administration can improve patient adherence to medical treatment for chronic obstructive pulmonary disease (COPD. To our knowledge, as of November 2014, the safety and the efficacy of QVA149 have been evaluated in 14 randomized controlled trials. The 14 trials generally showed good safety profiles, and there were better or not-inferior bronchodilator effects of QVA149 when compared with placebo, or other inhaled medication. According to the Japanese Respiratory Society guidelines, QVA149 is a combination of the two first-line bronchodilators. Our meta-analysis indicated that QVA149 is superior to the salmeterol–fluticasone combination to treat COPD in respect of the frequency of adverse effects, exacerbation, pneumonia, and improvement of trough forced expiratory volume in 1 second (FEV1. Thus, we believe that QVA149 can be a key medication for COPD treatments. Keywords: bronchodilator agents, dry powder inhalers, delivery of health care, guideline, meta-analysis, muscarinic antagonists 

  16. Role of once-daily glycopyrronium bromide (NVA237 in the management of COPD

    D’Urzo A

    2013-08-01

    Full Text Available Anthony D'UrzoDepartment of Family and Community Medicine, University of Toronto, Toronto, ON, CanadaAbstract: Progressive airflow limitation is a hallmark feature of chronic obstructive pulmonary disease (COPD that ultimately leads to breathlessness, impaired quality of life, and reduced exercise capacity. Pharmacotherapy is used in patients with COPD to prevent and control symptoms, reduce both the frequency and severity of exacerbations, improve health status, and increase exercise tolerance. These strategies are intended to address management issues which promote both current disease control and a reduction in the risk of disease deterioration in the future. At the present time, long-acting β2-agonists (LABAs and long-acting muscarinic antagonists (LAMAs are available for maintenance therapy in patients with persistent symptoms. Tiotropium was the first LAMA to be approved for management of COPD, and many studies have described its beneficial effects on multiple clinically relevant outcomes. Glycopyrronium bromide (NVA237, a new LAMA, has been developed and received regulatory approval for management of COPD in a number of countries around the world. Results from pivotal Phase III trials suggest that NVA237 is safe and well tolerated in patients with moderate to severe COPD, and provides rapid and sustained improvements in lung function. Further, these changes are associated with statistically and clinically meaningful improvements in dyspnea, health-related quality of life, and exercise tolerance. Treatment with NVA237 also results in a significant reduction in risk of exacerbations and the need for rescue medication, and has been comparable with tiotropium with respect to safety and efficacy outcomes. Finally, emerging data indicate that NVA237 is efficacious both as monotherapy and in combination with indacaterol.Keywords: glycopyrronium bromide, NVA237, chronic obstructive pulmonary disease, inhaled long-acting bronchodilators

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

    Jones PW

    2015-03-01

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

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

    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)

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

    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.

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

    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

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

    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.

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

    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.

  3. Strong Improper Ferroelasticity and Weak Canted Ferroelectricity in a Martensitic-Like Phase Transition of Diisobutylammonium Bromide.

    Piecha-Bisiorek, Anna; Białoska, Agata; Jakubas, Ryszard; Zieliski, Piotr; Wojciechowska, Martyna; Gałzka, Mirosław

    2015-09-01

    Diisobutylammonium bromide is found to be a unique improper ferroelastic in which the elastic degrees of freedom seem to play the essential role, giving rise to a domain pattern resembling that of martensitic phase transitions. A weak canted ferroelectricity turns out switchable by an electric field. PMID:26192617

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

    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.

  5. The vapour pressures over saturated aqueous solutions of cadmium chloride, cadmium bromide, cadmium iodide, cadmium nitrate, and cadmium sulphate

    Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)]. E-mail: apelblat@bgu.ac.il; Korin, Eli [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)

    2007-07-15

    Vapour pressures of water over saturated solutions of cadmium salts (chloride, bromide, iodide, nitrate, and sulphate) were determined over the temperature range 280 K to 322 K and compared with the literature data. The vapour pressures determined were used to obtain the water activities, osmotic coefficients and the molar enthalpies of vaporization in the (cadmium salt + water) systems.

  6. The vapour pressures over saturated aqueous solutions of cadmium chloride, cadmium bromide, cadmium iodide, cadmium nitrate, and cadmium sulphate

    Vapour pressures of water over saturated solutions of cadmium salts (chloride, bromide, iodide, nitrate, and sulphate) were determined over the temperature range 280 K to 322 K and compared with the literature data. The vapour pressures determined were used to obtain the water activities, osmotic coefficients and the molar enthalpies of vaporization in the (cadmium salt + water) systems

  7. MODIFICATION OF THE IODIMETRIC TITRATION METHOD FOR THE DETERMINATION OF BROMIDE AND ITS APPLICATION TO MIXED DOMESTIC - INDUSTRIAL WASTE EFFLUENTS

    The iodimetric titration method for the determination of bromide involves the observation of various color changes, making the method unsuitable for use with samples that are highly colored. A modification is described, which extends the usefulness of the method to highly colored...

  8. Biological half-life of bromide in the rat depends primarily on the magnitude of sodium intake

    Pavelka, Stanislav; Babický, Arnošt; Vobecký, Miloslav

    2005-01-01

    Roč. 54, č. 6 (2005), s. 639-644. ISSN 0862-8408 Institutional research plan: CEZ:AV0Z50110509 Keywords : biological half-life * bromide * sodium Subject RIV: ED - Physiology Impact factor: 1.806, year: 2005

  9. Effect of potential methyl bromide alternatives on plant parasitic nematodes and grape yield under vineyard replant conditions

    Root-knot (Meloidogyne spp.) and citrus (Tylenchulus semipenetrans) nematodes are often present in vineyards affected by “replant problems” of grapes in California. Methyl bromide (MB) has been used to control these nematodes and other soil borne pathogens prior to replanting new vineyards, but, exc...

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

    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.

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

    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

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

    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

  13. Palladium-catalyzed carbonylative Heck reaction of aryl bromides with vinyl ethers to 3-alkoxy alkenones and pyrazoles.

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

    2012-04-16

    Three COming together: The first carbonylative Heck coupling reaction of aryl bromides and vinyl ethers leading to 1-aryl-3-alkoxy-2-propen-1-ones has been established (see scheme). Based on this coupling methodology, a novel one-pot synthesis of aryl-substituted pyrazoles was also realized. PMID:22422673

  14. Palladium(0)-catalyzed cross-coupling of 1,1-diboronates with vinyl bromides and 1,1-dibromoalkenes.

    Li, Huan; Zhang, Zhikun; Shangguan, Xianghang; Huang, Shan; Chen, Jun; Zhang, Yan; Wang, Jianbo

    2014-10-27

    Palladium-catalyzed cross-coupling reactions of 1,1-diboronates with vinyl bromides and dibromoalkenes were found to afford 1,4-dienes and allenes, respectively. These reactions utilize the high reactivities of both 1,1-diboronates and allylboron intermediates generated in the initial coupling. PMID:25213194

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

    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. PMID:26490534

  16. Reasoned opinion on the review of the existing maximum residue levels (MRLs for methyl bromide according to Article 12 of Regulation (EC No 396/2005

    European Food Safety Authority

    2013-07-01

    Full Text Available According to Article 12 of Regulation (EC No 396/2005, the European Food Safety Authority (EFSA has reviewed the Maximum Residue Levels (MRLs currently established at European level for the pesticide active substance methyl bromide. Although this active substance is no longer authorised within the European Union, guideline levels for methyl bromide (at point of retail sale or when offered for consumption and MRLs for bromide ion, which is a relevant metabolite of methyl bromide, were established by the Codex Alimentarius Commission (CXLs. Regarding methyl bromide, the default MRL of 0.01 mg/kg as defined by Regulation (EC No 396/2005 is compliant with the Codex guideline levels and provides a satisfactory level of protection for the European consumer but it could not be demonstrated that the default MRL can be achieved in routine enforcement. Moreover, based on the assessment of the available data, some CXLs were found not to be adequately supported by data and the consumer risk assessment could not be finalised, as the toxicological reference values of bromide ion need to be revised and only few information on the natural occurrence of bromide ion in food was available to EFSA. Hence, further consideration by risk managers is needed.

  17. Use of lanthanum bromide detectors to augment site surveys for depleted uranium - 59169

    A variety of systems have now been described for use in surveying sites for anthropogenic radiological contamination. Virtually all of these include use of sodium iodide detectors and register detection data with global positioning satellite data. This paper demonstrates how lanthanum bromide detectors can be used to augment existing field surveys in a manner to reduce uncertainty in areas of low count rates and to discriminate between depleted uranium and naturally occurring uranium. The survey system described is equipped with large (20 x 20 x 100 cm) sodium iodide (Alpha Spectra) and 7.5 x 7.5 cm lanthanum bromide (Saint Gobain) detectors. Additional radiological detection equipment (DigiBase) was obtained from ORTEC with survey data collected in the List Mode. Data collected in surveys were then used to generate digital maps using GeoSoft's Oasis Montaj. Software has been developed to automatically identify areas of increased count rates using user-defined thresholds. This software can collect the count data for the masked area and generate a composite spectrum that can be compared to a reference spectrum believed to represent an uncontaminated area. Ratios of counts attributed to protactinium-234m (Pa-234m) are compared to counts attributed to Bismuth-214 (Bi- 214) for both the composite filed survey spectrum and the reference spectrum. Soil samples have been collected from selected sites over a range of soil and geology types for the purpose of collecting data comparing high purity germanium (HPGe) detector and lanthanum bromide (LaBr) detector spectra. These samples have come from areas believed to be devoid of depleted uranium contamination and from areas expected to have higher concentrations of naturally occurring uranium. A library of HPGe and LaBr spectra have been collected comparing: (1) background soil samples with, (2) spectra from the same samples that have been doped with half the remediation threshold activity of depleted uranium, and (3) the

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

    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

  19. Advanced oxidation of bromide-containing drinking water: a balance between bromate and trihalomethane formation control.

    Wang, Yongjing; Yu, Jianwei; Han, Po; Sha, Jing; An, Tao; Li, Wei; Liu, Juan; Yang, Min

    2013-11-01

    Addition of H202 has been employed to repress bromate formation during ozonation of bromide-containing source water. However, the addition of H2O2 will change the oxidation pathways of organic compounds due to the generation of abundant hydroxyl radicals, which could affect the removal efficacy of trihalomethane precursors via the combination of ozone and biological activated carbon (O3-BAC). In this study, we evaluated the effects of H2O2 addition on bromate formation and trihalomethane formation potential (THMFP) reduction during treatment of bromide-containing (97.6-129.1 microg/L) source water by the O3-BAC process. At an ozone dose of 4.2 mg/L, an H2O2/O3 (g/g) ratio of over 1.0 was required to maintain the bromate concentration below 10.0 microg/L, while a much lower H2O2/O3 ratio was sufficient for a lower ozone dose. An H2O2/O3 (g/g) ratio below 0.3 should be avoided since the bromate concentration will increase with increasing H2O2 dose below this ratio. However, the addition of H202 at an ozone dose of 3.2 mg/L and an H2O2/O3 ratio of 1.0 resulted in a 43% decrease in THMFP removal when comparedwith the O3-BAC process. The optimum H2O2/O3 (g/g) ratio for balancing bromate and trihalomethane control was about 0.7-1.0. Fractionation of organic materials showed that the addition of H2O2 decreased the removal efficacy of the hydrophilic matter fraction of DOC by ozonation and increased the reactivity of the hydrophobic fractions during formation of trihalomethane, which may be the two main reasons responsible for the decrease in THMFP reduction efficacy. Overall, this study clearly demonstrated that it is necessary to balance bromate reduction and THMFP control when adopting an H2O2 addition strategy. PMID:24552044

  20. Persistent modification of Nav1.9 following chronic exposure to insecticides and pyridostigmine bromide

    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 Nav1.8, but increased Kv7 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 Nav1.9 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 Nav1.9, but significant increases in the amplitude of Nav1.9 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 Nav1.9 in skin, muscle and vascular nociceptors. In conclusion, chronic exposure to Gulf War agents produced long term changes in the amplitude of Nav1.9 expressed in muscle and vascular nociceptors. The reported increases in Kv7 amplitude may have been an adaptive response to increased Nav1.9, and effectively suppressed behavioral pain measures in the post treatment period. Factors that alter the balance between Nav1.9 and Kv7 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 unchanged. • The amplitude and conductance of Nav1.9 were

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

    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

  2. Synthesis of N-Aryl-2-allyl Pyrrolidines via Palladium-catalyzed Carboamination Reactions of γ-(N-Arylamino)alkenes with Vinyl Bromides

    Ney, Joshua E.; Hay, Michael B.; Yang, Qifei; Wolfe, John P.

    2005-01-01

    A palladium-catalyzed carboamination reaction of γ-N-arylamino alkenes with vinyl bromides that affords N-aryl-2-allyl pyrrolidines is described. These reactions proceed with high diastereoselectivity for the formation of trans-2,3- and cis-2,5-disubstituted pyrrolidines. Conditions for a tandem N-arylation/carboamination sequence that leads to the formation of an N-aryl-2-allyl pyrrolidine or indoline via the coupling of a primary γ-amino alkene, an aryl bromide, and a vinyl bromide are also...

  3. Dehalogenative Homocoupling of Terminal Alkynyl Bromides on Au(111): Incorporation of Acetylenic Scaffolding into Surface Nanostructures.

    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

  4. Methyl chloride and methyl bromide emissions from baking: an unrecognized anthropogenic source.

    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

  5. Modification of radiosensitivity by ethidium bromide in nuclear division cycle of physarum polycephalum

    Hosoda, Eiko (Tokyo Metropolitan Isotope Research Center (Japan))

    1990-02-01

    The effect of ethidium bromide (EB) on mitotic retardation by {sup 60}Co-{gamma} irradiation was investigated in the naturally synchronous nuclear division cycle of plasmodium of Physarum polycephalum, using EB in concentration experimentally found to be uninhibitory to plasmodial growth; 0.5 {mu}M. Plasmodia were cultured with nutrient medium containing or not containing 0.5 {mu} M EB, and after the start of the second nuclear division cycle, were irradiated at 4 time points (in the middle G{sub 2} phase, in the early G{sub 2} phase, in the middle S phase, and in the early S phase) by {gamma}-rays of 2.8 to 28 Gy (0.28 to 2.8 KRad). The delay of the next mitosis relative to non-irradiated controls were examined, in both EB treated and untreated plasmodia respectively. EB treatment increased mitotic delay in the middle G{sub 2} phase gradually with dose, and in the early G{sub 2} phase at doses higher than about 20 Gy. EB treatment, on the other hand, on the other hand, reduced mitotic delay in the early S phase especially at higher doses. In the middle S phase, significant effects of EB treatment were not shown. Thus it has been revealed that EB increases or reduces plasmodial radiosensitivity dependently both on nuclear division cycle and on {gamma}-ray intensity. (author).

  6. Phospholipid decoration of microcapsules containing perfluorooctyl bromide used as ultrasound contrast agents.

    Díaz-López, Raquel; Tsapis, Nicolas; Libong, Danielle; Chaminade, Pierre; Connan, Carole; Chehimi, Mohamed M; Berti, Romain; Taulier, Nicolas; Urbach, Wladimir; Nicolas, Valérie; Fattal, Elias

    2009-03-01

    We present here an easy method to modify the surface chemistry of polymeric microcapsules of perfluorooctyl bromide used as ultrasound contrast agents (UCAs). Capsules were obtained by a solvent emulsification-evaporation process with phospholipids incorporated in the organic phase before emulsification. Several phospholipids were reviewed: fluorescent, pegylated and biotinylated phospholipids. The influence of phospholipid concentration on microcapsule size and morphology was evaluated. Only a fraction of the phospholipids is associated to microcapsules, the rest being dissolved with the surfactant in the aqueous phase. Microscopy shows that phospholipids are present within the shell and that the core/shell structure is preserved up to 0.5 mg fluorescent phospholipids, up to about 0.25 mg pegylated phospholipids or biotinylated phospholipids (for 100 mg of polymer, poly(lactide-co-glycolide) (PLGA)). HPLC allows quantifying phospholipids associated to capsules: they correspond to 10% of pegylated phospholipids introduced in the organic phase. The presence of pegylated lipids at the surface of capsules was confirmed by X-ray photon electron spectroscopy (XPS). The pegylation did not modify the echographic signal arising from capsules. Finally biotinylated microcapsules incubated with neutravidin tend to aggregate, which confirms the presence of biotin at the surface. These results are encouraging and future work will consist of nanocapsule surface modification for molecular imaging. PMID:19097640

  7. The performance of PEGylated nanocapsules of perfluorooctyl bromide as an ultrasound contrast agent.

    Díaz-López, Raquel; Tsapis, Nicolas; Santin, Mathieu; Bridal, Sharon Lori; Nicolas, Valérie; Jaillard, Danielle; Libong, Danielle; Chaminade, Pierre; Marsaud, Véronique; Vauthier, Christine; Fattal, Elias

    2010-03-01

    The surface of polymeric nanocapsules used as ultrasound contrast agents (UCAs) was modified with PEGylated phospholipids in order to escape recognition and clearance by the mononuclear phagocyte system and achieve passive tumor targeting. Nanocapsules consisted of a shell of poly(lactide-co-glycolide) (PLGA) encapsulating a liquid core of perfluorooctyl bromide (PFOB). They were decorated with poly(ethylene glycol-2000)-grafted distearoylphosphatidylethanolamine (DSPE-PEG) incorporated in the organic phase before the solvent emulsification-evaporation process. The influence of DSPE-PEG concentration on nanocapsule size, surface charge, morphology, hydrophobicity and complement activation was evaluated. Zeta potential measurements, Hydrophobic interaction chromatography and complement activation provide evidence of DSPE-PEG presence at nanocapsule surface. Electronic microscopy reveals that the core/shell structure is preserved up to 2.64 mg of DSPE-PEG for 100 mg PLGA. In vivo ultrasound imaging was performed in mice bearing xenograft tumor with MIA PaCa-2 cells, either after an intra-tumoral or intravenous injection of nanocapsules. Tumor was observed only after the intra-tumoral injection. Despite the absence of echogenic signal in the tumor after intravenous injection of nanocapsules, histological analysis reveals their accumulation within the tumor tissue demonstrating that tissue distribution is not the unique property required for ultrasound contrast agents to be efficient. PMID:19948357

  8. Swelling behaviour of amphiphilic poly (methacryloxyethl dimethylalkane ammonium bromide) gels in alcohol/water solvent systems

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

    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.

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

    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.

  11. Ferrate(VI): a novel oxidant for degradation of cationic surfactant - cetylpyridinium bromide.

    Yang, Weihua; Lin, Xiaoyan; Wang, Honghui; Yang, Wutao

    2013-01-01

    Ferrate(VI) is an efficient multi-functional water treatment reagent that has several novel properties, such as strong oxidation, absorption, flocculation, disinfection and deodorization. The removal of cationic surfactants based on ferrate (K2FeO4) was performed in the case of cetylpyridinium bromide (CPB). The influence of operating variables on the mineralization efficiency was studied as a function of ferrate dosage, initial pH and reaction time. Total organic carbon (TOC), UV and infrared spectra were performed to gain a better understanding of the degradation process. Results show that the optimal treatment conditions are as follows, solution initial pH is over 5, oxidation time is 5 min and ferrate dosage is 1.5 times that of CPB. The removal efficiency of CPB above 99% and TOC removal percentage of 91.3% can be achieved in minutes. The reaction of CPB with K2FeO4 responds to a second-order kinetic law. PMID:23676386

  12. Efficient bacteria capture and inactivation by cetyltrimethylammonium bromide modified magnetic nanoparticles.

    Jin, Yinjia; Deng, Jun; Liang, Jialiang; Shan, Chao; Tong, Meiping

    2015-12-01

    Functionalized magnetic nanoparticles have shown great application potentials in water treatment processes especially for bacterial removal. Antibacterial agent, cetyltrimethylammonium bromide (CTAB), was employed to modify Fe3O4 nanoparticles to fabricate bactericidal paramagnetic nanoparticles (Fe3O4@CTAB). The as-prepared Fe3O4@CTAB could effectively capture both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis from water. For both cell types, more than 99% of bacteria with initial concentration of 1.5 × 10(7)CFU/mL could be inactivated by Fe3O4@CTAB (0.5 g/L) within 60 min. Fe3O4@CTAB could remove more than 99% of cells over a wide pH (from 3 to 10) and solution ionic strength range (from 0 to 1000 mM). The copresence of sulfate and nitrate did not affect the bacterial capture efficiencies, whereas, phosphate and silicate slightly decreased the bacterial removal rates. However, more than 91% and 81% of cells could be captured at 10mM of phosphate and silicate, respectively. Over 80% of cells could be removed even in the presence of 10mg/L of humic acid. Moreover, Fe3O4@CTAB exhibited good reusability, and greater than 83% of cells could be captured even in the fifth regeneration cycle. Fe3O4@CTAB prepared in this study have great application potentials for water disinfection. PMID:26496472

  13. Removal of hexavalent chromium by using red mud activated with cetyltrimethylammonium bromide.

    Li, Deliang; Ding, Ying; Li, Lingling; Chang, Zhixian; Rao, Zhengyong; Lu, Ling

    2015-01-01

    The removal of hexavalent chromium [Cr(VI)] from aqueous solution by using red mud activated with cetyltrimethylammonium bromide (CTAB) was studied. The optimum operation parameters, such as CTAB concentration, pH values, contact time, and initial Cr(VI) concentration, were investigated. The best concentration of CTAB for modifying red mud was found to be 0.50% (mCTAB/VHCl,0.6 mol/L). The lower pH (removal of Cr(VI). Red mud activated with CTAB can greatly improve the removal ratio of Cr(VI) as high as four times than that of original red mud. Adsorption equilibrium was reached within 30 min under the initial Cr(VI) concentration of 100 mg L(-1). The isotherm data were analysed using Langmuir and Freundlich models. The adsorption of Cr(VI) on activated red mud fitted well to the Langmuir isotherm model, and the maximum adsorption capacity was estimated as 22.20 mg g(-1) (Cr/red mud). The adsorption process could be well described using the pseudo-second-order model. The result shows that activated red mud is a promising agent for low-cost water treatment. PMID:25299348

  14. An effective method for thallium bromide purification and research on crystal properties

    Thallium bromide (TlBr) is a promising candidate for room-temperature X- and gamma-ray detectors in view of its excellent intrinsic features. However, material purity and crystal quality concerns still limit the use of TlBr crystals as detectors. In this work, a combination of hydrothermal recrystallization (HR) and vacuum distillation (VD) methods were applied to purify TlBr salts prior to crystal growth. Trace impurities at the ppb/ppm level were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The results showed that the impurity concentrations of the TlBr salt decreased significantly after HR and VD purification, and high performance of the resultant TlBr crystal in areas such as electrical and optical properties was achieved. The combination of HR and VD methods could fabricate purer material, with an order of magnitude higher resistivity and better optical quality, than HR or VD method used separately. The possible technological considerations affecting the parameters of the crystals are investigated. - Highlights: ► The effectiveness of purification can be increased by combining different purification methods. ► A pure material with a sum of impurity concentrations of approximately 300 ppb was obtained. ► Good electrical and optical properties were achieved via combination of purification methods.

  15. Interaction of cefadroxyl monohydrate with hexadecyltrimethyl ammonium bromide and sodium dodecyl sulfate

    Interaction of a cephalosporin antibiotic drug, cefadroxyl monohydrate (CFM) with hexadecyltrimethyl ammonium bromide (CTAB), a cationic surfactant, and sodium dodecyl sulfate (SDS), an anionic surfactant, has been studied in aqueous medium by conductivity measurement over a range of temperatures and salt concentrations. Values of critical micelle concentration (c*), degree of micelle ionization (α), and thermodynamic parameters have been determined for both the systems in pure water as well as in aqueous NaCl solution. For both (CFM + CTAB) and (CFM + SDS) systems, ΔGm0 values are negative which indicate that the drug mediated ionic micelle formation processes are thermodynamically spontaneous. For (CFM + CTAB) system, the micellization is entropy controlled at lower temperatures whereas at higher temperatures it becomes both entropy and enthalpy controlled. The micellization of (CFM + SDS) system is entropy controlled over the range of temperatures studied and more so at lower temperature. In the presence of NaCl, enhancement of hydrophobic interaction is observed for both the systems at lower temperatures. A significant decrease of c* values in the presence of NaCl for both the surfactant systems indicates that CFM supported ionic micelle formation is much favoured in NaCl compared to that in pure water

  16. Irradiation as an alternative treatment to methyl bromide for insect control

    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)

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

    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.

  18. Partial and full stabilization of zirconia by calcium chloride and bromide additives

    Partial and full stabilization of zirconia was attempted by using stabilizers like calcium chloride and bromide (10, 15 and 20 mol per cent). The green mixture was heated in powder form in the temperature range of 300deg to 1300degC. The stabilization was studied through thermal analysis and powder X-ray diffraction techniques. The green mixture showed crystallinity only above 300degC. Crystal size increased with increase in calcination temperature. Calcined samples showed the presence of cubic/tetragonal phase along with a certain amount of monoclinic phase at room temperature. The intensity of the compound peak (30.2deg 2θ), where 10 mol per cent CaCl2 was used as stabilizer, in creased rapidly with temperature up to 550degC, while in case of CaBr2 stabilizer it increased rapidly up to 750degC. Above these temperatures, marginal increase in intensity was observed in both the cases. A comparative study shows that below 800degC firing temperature, CaCl2 was more effective than CaBr2. However, above this temperature the reverse was observed. In case of 15 and 20 mol per cent CaCl2 addition, formation of the cubic phase took place at 1550deg and 1300degC respectively. However, 20 mol per cent CaBr2 addition resulted in cubic and CaZrO3 phase formation. (author). 14 refs., 7 figs

  19. Simulation of solar lithium bromide-water absorption cooling system with parabolic trough collector

    Ahwaz is one of the sweltering cities in Iran where an enormous amount of energy is being consumed to cool residential places in a year. The aim of this research is to simulate a solar single effect lithium bromide-water absorption cooling system in Ahwaz. The solar energy is absorbed by a horizontal N-S parabolic trough collector and stored in an insulated thermal storage tank. The system has been designed to supply the cooling load of a typical house where the cooling load peak is about 17.5 kW (5 tons of refrigeration), which occurs in July. A thermodynamic model has been used to simulate the absorption cycle. The working fluid is water, which is pumped directly to the collector. The results showed that the collector mass flow rate has a negligible effect on the minimum required collector area, but it has a significant effect on the optimum capacity of the storage tank. The minimum required collector area was about 57.6 m2, which could supply the cooling loads for the sunshine hours of the design day for July. The operation of the system has also been considered after sunset by saving solar energy

  20. Synthesis, characterization and antibacterial properties of dihydroxy quaternary ammonium salts with long chain alkyl bromides.

    Liu, Wen-Shuai; Wang, Chun-Hua; Sun, Ju-Feng; Hou, Gui-Ge; Wang, Yu-Peng; Qu, Rong-Jun

    2015-01-01

    Five N-methyl-N-R-N,N-bis(2-hydroxyethyl) ammonium bromides (R = -benzyl (chloride, BNQAS), -dodecyl (C12QAS), -tetradecyl (C14QAS), -hexadecyl (C16QAS), -octadecyl (C18QAS)) were prepared based on N-methyldiethanolamine (MDEA) and halohydrocarbon. Five QAS were characterized by FTIR, NMR, and MS. BNQAS, C12QAS, C14QAS, and C16QAS were confirmed by X-ray single-crystal diffraction. Their antibacterial properties indicated good antibacterial abilities against E. coli, S. aureus, B. subtilis, especially C12QAS with the best antibacterial ability (100% to E. coli, 95.65% to S. aureus, and 91.41% to B. subtilis). In addition, C12QAS also displayed the best antifungal activities than BNQAS and C18QAS against Cytospora mandshurica, Botryosphaeria ribis, Physalospora piricola, and Glomerella cingulata with the ratio of full marks. The strategy provides a facile way to design and develop new types of antibacterial drugs for application in preventing the fruit rot, especially apple. PMID:25215430

  1. Stable bromine isotopic composition of methyl bromide released from plant matter

    Horst, Axel; Holmstrand, Henry; Andersson, Per; Thornton, Brett F.; Wishkerman, Asher; Keppler, Frank; Gustafsson, Örjan

    2014-01-01

    Methyl bromide (CH3Br) emitted from plants constitutes a natural source of bromine to the atmosphere, and is a component in the currently unbalanced global CH3Br budget. In the stratosphere, CH3Br contributes to ozone loss processes. Studies of stable isotope composition may reduce uncertainties in the atmospheric CH3Br budget, but require well-constrained isotope fingerprints of the source end members. Here we report the first measurements of stable bromine isotopes (δ81Br) in CH3Br from abiotic plant emissions. Incubations of both KBr-fortified pectin, a ubiquitous cell-stabilizing macromolecule, and of a natural halophyte (Salicornia fruticosa), yielded an enrichment factor (ε) of -2.00 ± 0.23‰ (1σ, n = 8) for pectin and -1.82 ± 0.02‰ (1σ, n = 4) for Salicornia (the relative amount of the heavier 81Br was decreased in CH3Br compared to the substrate salt). For short incubations, and up to 10% consumption of the salt substrate, this isotope effect was similar for temperatures from 30 up to 300 °C. For longer incubations of up to 90 h at 180 °C the δ81Br values increased from -2‰ to 0‰ for pectin and to -1‰ for Salicornia. These δ81Br source signatures of CH3Br formation from plant matter combine with similar data for carbon isotopes to facilitate multidimensional isotope diagnostics of the CH3Br budget.

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

    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.

  3. Spectroscopic study of tetradecyltrimethylammonium bromide Pt-C14TAB nanoparticles: Structure and Stability

    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.

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

    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.

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

    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.

  6. Preparation of WO3 Nanoparticles Using Cetyl Trimethyl Ammonium Bromide Supermolecular Template

    Nilofar Asim

    2009-01-01

    Full Text Available Problem statement: WO3 is one of the most interested metal oxides because of its application as catalysts, sensors, electrochromic devices, ceramic, solar cell, pigments and so on. More investigation is needed to find the good and low cost method for preparation of WO3 nanoparticles with uniform morphology and narrow distribution using a surfactant mediated method. Approach: In this study, the synthesis of WO3 nanoparticles was accomplished using a cationic surfactant (cetyl trimethyl ammonium bromide as the organic supermolecular template and WCl6 and NH4OH as the inorganic precursor and counter ion source, respectively. The effects of reaction temperature and surfactant concentration in particle size of resultant WO3 nanoparticles were investigated. Results: The different ranges of particle size and size distribution were obtained using different surfactant concentration and reaction temperature. The WO3 particles in the nanometer range (3-15 nm with uniform morphology and narrow distribution were obtained by optimization of reaction condition. X-ray diffraction, transmission electron microscopy, variable pressure scanning electron microscope, X-ray photoelectron spectroscopy and UV-Vis spectroscopy were used to characterize the final products. The nanomaterials WO3 showed different pattern in UV-Vis spectroscopy compare to the bulk WO3. Conclusion: A relatively simple and effective procedure for synthesis of WO3 nanoparticles with mean size below 10 nm, narrow size distribution and high monodispersity using CTAB supramolecular template had been developed and optimized.

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

    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

  8. Formation of reversed micelles and W/O microemulsions of butyldodecyldimethylammonium bromide in chlorobenzene

    The limiting amounts of water solubilized by butyldodecyldimethylammonium bromide (BDDAB) in chlorobenzene increased rapidly at 0.01 molkg-1 surfactant concentration at 30degC. Using 1H NMR, fluorescence, and near infrared spectroscopic techniques, the solubilized states of water in the region obtained above 0.01 molkg-1 were examined as a function of Rw (=[H2O]/[BDDAB]) at various concentrations of surfactant. It was found from these spectral features that three types of water exist in varying proportions in the interior of reversed micelles, i.e., below Rw = 4 water is bound directly to the ionic head groups of the surfactant, in the range of Rw = 4-10 the succeeded water is held together with the hydrated ionic groups by hydrogen bonds, and above Rw = 10 bulk-like water is built up. These types of water could be discussed in connection with the formation of reversed and swollen micelles or W/O microemulsions. Further, the minimum Rw required for the formation of swollen micelles and W/O microemulsion and the critical swollen micelles or W/O microemulsion concentration could be estimated. (author)

  9. Bromide as chemical tracer to measure the liquid effluent flow at IPEN-CNEN/SP

    Silva, Douglas B.; Faustino, Mainara G.; Monteiro, Lucilena R.; Cotrim, Marycel E.B.; Pires, Maria Aparecida F., E-mail: dbsilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Due to recent changes in CONAMA Resolution 357, which occurred through the publication of Resolution 430, on May 13, 2011 that now set standards about the effluent release, IPEN-CNEN/SP initiated several actions to improve the Environmental Monitoring Program (PMA-Q) of stable chemical compounds. Besides various parameters (physical and chemical) established by CONAMA, the submission of an annual pollution inventory report became necessary. The liquid effluent flow measurement is required to implement this inventory. Thereby, this paper describes a study that uses bromide as a chemical tracer. This paper presents the results of 6 tracer releases in IPEN wastewater collection network between 2011 and 2012. Two tracer releases designs were performed: single pulse and continuous releases performed with 1 to 6 hours duration, done by using one single piston pump manufactured by DIONEX. After the release, one fraction of the effluent was collected every 15 minutes at IPEN effluent monitoring station. The tracer concentration in the effluent was analyzed by ion chromatography and flow was calculated considering the dilution in the system and pump flow set up for the release. The flow values were measured in 6 events were determined and evaluated as per Brazilian regulation requirements. Experimental designs to be implemented during 2013 monitoring were also discussed in this paper, contributing to legal compliance and to improve IPEN's Environmental Monitoring Program for stable chemical compounds (PMA-Q). (author)

  10. Characterization of Cetyltrimethylammonium Bromide/Hexanol Reverse Micelles by Experimentally Benchmarked Molecular Dynamics Simulations.

    Fuglestad, Brian; Gupta, Kushol; Wand, A Joshua; Sharp, Kim A

    2016-02-23

    Encapsulation of small molecules, proteins, and other macromolecules within the protective water core of reverse micelles is emerging as a powerful strategy for a variety of applications. The cationic surfactant cetyltrimethylammonium bromide (CTAB) in combination with hexanol as a cosurfactant is particularly useful in the context of solution NMR spectroscopy of encapsulated proteins. Small-angle X-ray and neutron scattering is employed to investigate the internal structure of the CTAB/hexanol reverse micelle particle under conditions appropriate for high-resolution NMR spectroscopy. The scattering profiles are used to benchmark extensive molecular dynamics simulations of this reverse micelle system and indicate that the parameters used in these simulations recapitulate experimental results. Scattering profiles and simulations indicate formation of homogeneous solutions of small approximately spherical reverse micelle particles at a water loading of 20 composed of ∼150 CTAB and 240 hexanol molecules. The 3000 waters comprising the reverse micelle core show a gradient of translational diffusion that reaches that of bulk water at the center. Rotational diffusion is slowed relative to bulk throughout the water core, with the greatest slowing near the CTAB headgroups. The 5 Å thick interfacial region of the micelle consists of overlapping layers of Br(-) enriched water, CTAB headgroups, and hexanol hydroxyl groups, containing about one-third of the total water. This study employs well-parametrized MD simulations, X-ray and neutron scattering, and electrostatic theory to illuminate fundamental properties of CTAB/hexanol reverse micelle size, shape, partitioning, and water behavior. PMID:26840651

  11. Pourbaix diagrams for titanium in concentrated aqueous lithium bromide solutions at 25 {sup o}C

    Munoz-Portero, M.J. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia (Spain); Garcia-Anton, J., E-mail: jgarciaa@iqn.upv.e [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia (Spain); Guinon, J.L.; Leiva-Garcia, R. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia (Spain)

    2011-04-15

    Research highlights: The titanium solubility range increases slightly with increasing Br{sup -} activity. The passivation area decreases slightly with increasing Br{sup -} activity. Immunity area increases slightly with increasing Br{sup -} activity. The titanium immunity disappears in the presence of titanium hydrides. TiH{sub 2} is the stable species at low potentials in the presence of titanium hydrides. - Abstract: Pourbaix diagrams (electrode potential-pH diagrams) for Ti-Br{sup -}-H{sub 2}O system at 25 {sup o}C 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-H{sub 2}O system at 25 {sup o}C. Comparison of the simple Ti-H{sub 2}O system with the diagrams of the Ti-Br{sup -}-H{sub 2}O system at 25 {sup o}C 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. Graphene oxide nanosheets/polymer binders as superior electrocatalytic materials for vanadium bromide redox flow batteries

    Few layered graphene oxide (GO) nanosheets with large specific surface area (42.1 m2 g−1) are successfully prepared by a modified Hummers method for use as electrodes in the vanadium bromide redox battery. The structure and physicochemical properties of GO are investigated by X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Cyclic voltammetry results indicate that GO nanosheets with polymer binder (i.e., polyvinylidiene fluoride (PVDF) or sulfonated poly(ether ether ketone) (SPEEK)) hybrids demonstrate more favorable electrocatalytic activity towards the Br−/Br3− and V3+/V2+ redox couples than the pure graphite. This is attributed to the large numbers of oxygen-containing functional groups on the GO nanosheet surface which can generate more active sites to catalyze the redox reactions. For the binder-based electrodes, the SPEEK based electrode gives the best electrochemical performance (e.g., lower overvoltage for both Br−/Br3− and V3+/V2+ redox couple reactions and higher peak currents for the V3+/V2+ redox couple).

  13. Dual bronchodilator therapy with aclidinium bromide/formoterol fumarate for chronic obstructive pulmonary disease.

    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

  14. A Facile Electrochemical Sensor for Nonylphenol Determination Based on the Enhancement Effect of Cetyltrimethylammonium Bromide

    Qing Lu

    2013-01-01

    Full Text Available A facile electrochemical sensor for the determination of nonylphenol (NP was fabricated in this work. Cetyltrimethylammonium bromide (CTAB, which formed a bilayer on the surface of the carbon paste (CP electrode, displayed a remarkable enhancement effect for the electrochemical oxidation of NP. Moreover, the oxidation peak current of NP at the CTAB/CP electrode demonstrated a linear relationship with NP concentration, which could be applied in the direct determination of NP. Some experimental parameters were investigated, such as external solution pH, mode and time of accumulation, concentration and modification time of CTAB and so on. Under optimized conditions, a wide linear range from 1.0 × 10−7 mol·L−1 to 2.5 × 10−5 mol·L−1 was obtained for the sensor, with a low limit of detection at 1.0 × 10−8 mol·L−1. Several distinguishing advantages of the as-prepared sensor, including facile fabrication, easy operation, low cost and so on, suggest a great potential for its practical applications.

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

    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

  16. Effect of regenerated soil structure on unsaturated transport of Escherichia coli and bromide

    Safadoust, A.; Mahboubi, A. A.; Mosaddeghi, M. R.; Gharabaghi, B.; Unc, A.; Voroney, P.; Heydari, A.

    2012-04-01

    SummaryThis study was conducted to assess the role of the regeneration of soil structure by physical weathering of soils in columns on the transport of Nalidixic acid-resistant Escherichia coli strain (E. coli NAR) and also Bromide (Br). Leaching experiments were carried out at steady-state flow conditions, under a suction head of 5 cm, through columns of repacked and weathered clay loam (CL) and sandy loam (SL) soils. A pulse-type boundary condition was used and breakthrough curves for bacteria and Br were obtained at three depths during a 24 h leaching experiment. Observed data were analyzed employing the mobile-immobile water (MIM) models for repacked or weathered soil columns using HYDRUS-1D code. Both models described well the effluent concentrations. Calibration of the models to match the observed breakthrough curves of Br and E. coli NAR resulted in a smaller value of dispersivity for the later. For bacteria, the fitted attachment and straining coefficients increased with the clay content of the soil. Earlier peaks in the breakthrough curves were observed for the weathered soil columns. This was attributed to increased pore connectivity associated with weathering. In contrast the balanced and symmetrical shape of the breakthrough curves from the repacked soil columns indicates that leaching occurred mainly through matrix flow.

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

    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)

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

    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)

  19. Insights into the energetics and mechanism underlying the interaction of tetraethylammonium bromide with proteins

    Calorimetry has been employed to investigate the quantitative energetic aspects and mechanism underlying protein-tetraethylammonium bromide (TEAB) interactions. Differential scanning calorimetry and UV-Visible spectroscopy have been used to study the thermal unfolding of three proteins of different structure and function (bovine serum albumin, α-lactalbumin, and bovine pancreatic ribonuclease A). The mode of interaction has been studied by using isothermal titration calorimetry, which demonstrates the absence of appreciable specific binding of TEAB to the protein. This suggests the involvement of solvent mediated effects and, possibly weak non-specific binding. The thermal unfolding transitions were found to be calorimetrically reversible for α-lactalbumin and bovine pancreatic ribonuclease A and partially reversible in the case of bovine serum albumin. The results indicate protein destabilization promoted by the TEAB interaction. The preferential interaction parameters of TEAB with α-lactalbumin and ribonuclease A confirm that an increased interaction of the hydrophobic groups of the TEAB with that of the protein upon denaturation is responsible for the reduced thermal stability of the protein. The decrease in the thermal stability of proteins in the presence of TEAB is well supported by a red shift in the intrinsic fluorescence of these proteins leading to conformational change thereby shifting the native ↔ denatured equilibrium towards right. The forces responsible for the thermal denaturation of the proteins of different structure and function in the presence of TEAB are discussed

  20. Determination of Trace Nickel in Natural Water by Flow Injection Analysis with Cetrimonium Bromide as Sensitizer

    Zhao, Z. X.; Zhang, C. X.; Li, N.; Zhang, X. S.

    2015-11-01

    2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) is a highly sensitive chromogenic reagent that can react with most of the transition and alkaline earth metals. The Ni(II)-5-Br-PADAP complex is more stable than other metal-5-Br-PADAP complexes. In the presence of seignette salt, ethylenediaminetetraacetic acid (EDTA) can decompose most of the 5-Br-PADAP complexes with metals except for iron, cobalt, and nickel. Cetrimonium bromide (CTMAB) as a sensitizer for the color reaction forms a ternary complex with nickel and 5-Br-PADAP with maximum absorption wavelength at 561 nm. CTMAB can significantly improve the sensitivity and selectivity of nickel determination, as well as the stability and solubility of compounds. In this study, the determination of trace nickel in natural water samples was performed by flow injection analysis. The calibration lines were established in the range of 0-200 μg/l of nickel (n ≥ 3), and the limit of detection was 0.093 μg/l. The relative standard deviation was 2.55% for the determination of 25 μg/l nickel (n ≥ 20). The recoveries of this method ranged from 91.0 to 101% for environmental water samples. A large amount of aluminum, calcium, cadmium, copper, bicarbonate, magnesium, zinc, and iron, except for cobalt, did not interfere with the determination of nickel.

  1. Evaluation of methyl bromide alternatives efficacy against soil-borne pathogens, nematodes and soil microbial community.

    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.

  2. Second law-based thermodynamic analysis of water-lithium bromide absorption refrigeration system

    In this study, the first and the second law of thermodynamics are used to analyze the performance of a single-stage water-lithium bromide absorption refrigeration system (ARS) when some working parameters are varied. A mathematical model based on the exergy method is introduced to evaluate the system performance, exergy loss of each component and total exergy loss of all the system components. Parameters connected with performance of the cycle-circulation ratio (CR), coefficient of performance (COP), Carnot coefficient of performance (COPc ), exergetic efficiency (ξ) and efficiency ratio (τ)-are calculated from the thermodynamic properties of the working fluids at various operating conditions. Using the developed model, the effect of main system temperatures on the performance parameters of the system, irreversibilities in the thermal process and non-dimensional exergy loss of each component are analyzed in detail. The results show that the performance of the ARS increases with increasing generator and evaporator temperatures, but decreases with increasing condenser and absorber temperatures. Exergy losses in the expansion valves, pump and heat exchangers, especially refrigerant heat exchanger, are small compared to other components. The highest exergy loss occurs in the generator regardless of operating conditions, which therefore makes the generator the most important component of the cycle

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

    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.

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

    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

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

    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.

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

    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

  7. Corrosion rate of copper in aqueous lithium bromide concentrated solutions at room temperature by immersion tests

    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)

  8. Vapor-liquid equilibria of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems

    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.

  9. Stabilization of Organic-Inorganic Perovskite Layers by Partial Substitution of Iodide by Bromide in Methylammonium Lead Iodide.

    Ruess, Raffael; Benfer, Felix; Böcher, Felix; Stumpp, Martina; Schlettwein, Derck

    2016-05-18

    Thin films of the methylammonium lead halides CH3 NH3 Pb(I1-x Brx )3 are prepared on fluorine-doped tin oxide substrates and exposed to humid air in the dark and under illumination. To characterize the stability of the materials, UV/Vis spectra are acquired at fixed intervals, accompanied by XRD, energy-dispersive X-ray spectroscopy, SEM, and confocal laser scanning microscopy. Different degradation mechanisms are observed depending on the environmental conditions. It is found that bromide can successfully suppress the transformation of the perovskite into the monohydrate, presumably owing to stronger hydrogen-bonding interactions with the organic cation. However, under illumination in humid air, rather rapid decomposition of the perovskites was still observed, which is due to phase segregation. The use of increased bromide content in methylammonium lead halide absorbers is discussed in terms of their application in perovskite solar cells. PMID:26853438

  10. Effect of bromide on the interfacial structure of aqueous tetrabutylammonium iodide: Photoelectron spectroscopy and molecular dynamics simulations

    Winter, B.; Weber, R.; Hertel, I. V.; Faubel, M.; Vrbka, Luboš; Jungwirth, Pavel

    2005-01-01

    Roč. 410, - (2005), s. 222-227. ISSN 0009-2614 R&D Projects: GA MŠk(CZ) LC512 Grant ostatní: NSF(US) CHE0431312; NSF(US) CHE0209719 Institutional research plan: CEZ:AV0Z40550506 Keywords : bromide * tetrabutylammonium * molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.438, year: 2005

  11. Deformation of swollen erythrocytes provides a model of sickling-induced leak pathways, including a novel bromide-sensitive component.

    Sugihara, T; Yawata, Y; Hebbel, R P

    1994-05-01

    Deoxygenation-induced red blood cell (RBC) sickling probably activates multiple cation leak pathways. In an attempt to model this, we examined the net passive K efflux ("K leak") from normal and sickle RBCs undergoing elliptical deformation in hypotonic media (200 mOsmol/L). This hypotonic deformation activates two deformation-dependent K leak pathways that are not detectable during the balanced leak (Kefflux = Nainflux) resulting from deformation of RBCs in isotonic medium. These are (1) a calcium-dependent leak component and (2) a novel leak pathway that is inhibited by substitution of bromide (but not sulfamate) for chloride, which converts the unbalanced K leak (Kefflux > Nainflux) of hypotonic deformation to a residual balanced leak. This dramatic effect of hypotonic deformation is reversible, is detected in both normal and sickle RBCs, and is inhibited significantly by 4,4'-diisothiocyano-2,2'-stilbene disulfonate. Remarkably, bromide also inhibits by 55% the K leak resulting from authentic deoxygenation-induced RBC sickling and, thereby, blunts the imbalance of accompanying monovalent cation leaks. The unique effect of bromide is not readily explainable on the basis of known behaviors of known ion leak/transport pathways. The mechanical threshold for triggering K leak during hypotonic deformation is at applied shear stress of 164 dyne/cm2, a value similar to the abnormal susceptibility we previously found for oxygenated sickle RBCs during isotonic deformation. These data suggest that membrane stretch accompanying hypotonic deformation activates the same multiple leak pathways that contribute to net K leak during authentic RBC sickling, including a previously unknown bromide-sensitive leak. PMID:7513211

  12. Efficacy of Tiotropium Bromide and Rehabilitation Treatment on Pulmonary Function of Patients With Sulfur Mustard Lung Injury

    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...

  13. Palladium-Catalyzed α-Arylation of Aryl Acetic Acid Derivatives via Dienolate Intermediates with Aryl Chlorides and Bromides

    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.

  14. Estimating groundwater recharge in Hebei Plain, China under varying land use practices using tritium and bromide tracers

    Wang, B.; Jin, M.; Nimmo, J.R.; Yang, L.; Wang, W.

    2008-01-01

    Tritium and bromide were used as applied tracers to determine groundwater recharge in Hebei Plain, North China, to evaluate the impacts of different soil types, land use, irrigation, and crop cultivation practice on recharge. Additional objectives were to evaluate temporal variability of recharge and the effect on results of the particular tracer used. Thirty-nine profiles at representative locations were chosen for investigation. Average recharge rates and recharge coefficient determined by tritium and bromide tracing for different sites were 0.00-1.05 mm/d and 0.0-42.5%, respectively. The results showed relative recharge rates for the following paired influences (items within each pair are listed with the influence producing greater recharge first): flood-irrigated cropland and non-irrigated non-cultivation land, flood irrigation (0.42-0.58 mm/d) and sprinkling irrigation (0.17-0.23 mm/d), no stalk mulch (0.56-0.80 mm/d) and stalk mulch (0.44-0.60 mm/d), vegetable (e.g. Chinese cabbage and garlic, 0.70 mm/d) and wheat-maize (0.38 mm/d), peanut (0.51 mm/d) and peach (0.43 mm/d). The results also showed greater recharge for the first year of tracer travel than for the second. Because total precipitation and irrigation were greater in the first year than in the second, this may reflect temporal variability of recharge. The method may not be applicable where the water table is shallow (less than 3 m). A comparison of the near-ideal tritium tracer with the more common but less ideal bromide showed that bromide moved approximately 23% faster than tritiated water, perhaps because of anion exclusion. ?? 2008 Elsevier B.V.

  15. Effects of Soil and Water Content on Methyl Bromide Oxidation by the Ammonia-Oxidizing Bacterium Nitrosomonas europaea†

    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...

  16. Relations among the values of biological half-lives of bromide, chloride and sodium in the rat

    Pavelka, Stanislav

    Leipzig : SchubertVerlag, 2004 - (Anke, M.; Flachowsky, G.; Kisters, K.; Schafer, U.; Schenkel, H.; Seifert, M.; Stoeppler, M.), s. 782-790 ISBN 3-929526-78-6. - (1). [Workshop Macro and Trace Elements/Mengen- und Spurenelemente 2004 /22./. Jena (DE), 24.09.2004-25.09.2004] Institutional research plan: CEZ:AV0Z5011922 Keywords : biological half-life * bromide * chloride Subject RIV: ED - Physiology

  17. Evaluating equilibrium and non-equilibrium transport of bromide and isoproturon in disturbed and undisturbed soil columns.

    Dousset, S; Thevenot, M; Pot, V; Simunek, J; Andreux, F

    2007-12-01

    In this study, displacement experiments of isoproturon were conducted in disturbed and undisturbed columns of a silty clay loam soil under similar rainfall intensities. Solute transport occurred under saturated conditions in the undisturbed soil and under unsaturated conditions in the sieved soil because of a greater bulk density of the compacted undisturbed soil compared to the sieved soil. The objective of this work was to determine transport characteristics of isoproturon relative to bromide tracer. Triplicate column experiments were performed with sieved (structure partially destroyed to simulate conventional tillage) and undisturbed (structure preserved) soils. Bromide experimental breakthrough curves were analyzed using convective-dispersive and dual-permeability (DP) models (HYDRUS-1D). Isoproturon breakthrough curves (BTCs) were analyzed using the DP model that considered either chemical equilibrium or non-equilibrium transport. The DP model described the bromide elution curves of the sieved soil columns well, whereas it overestimated the tailing of the bromide BTCs of the undisturbed soil columns. A higher degree of physical non-equilibrium was found in the undisturbed soil, where 56% of total water was contained in the slow-flow matrix, compared to 26% in the sieved soil. Isoproturon BTCs were best described in both sieved and undisturbed soil columns using the DP model combined with the chemical non-equilibrium. Higher degradation rates were obtained in the transport experiments than in batch studies, for both soils. This was likely caused by hysteresis in sorption of isoproturon. However, it cannot be ruled out that higher degradation rates were due, at least in part, to the adopted first-order model. Results showed that for similar rainfall intensity, physical and chemical non-equilibrium were greater in the saturated undisturbed soil than in the unsaturated sieved soil. Results also suggested faster transport of isoproturon in the undisturbed soil due

  18. Palladium-Catalyzed Heck Coupling Reaction of Aryl Bromides in Aqueous Media Using Tetrahydropyrimidinium Salts as Carbene Ligands

    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.

  19. Delivery of albuterol and ipratropium bromide from two nebulizer systems in chronic stable asthma. Efficacy and pulmonary deposition

    Johnson, M.A.; Newman, S.P.; Bloom, R.; Talaee, N.; Clarke, S.W.

    1989-07-01

    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 /sup 99m/Tc-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.

  20. Bi6(SeO3)3O5Br2: A new bismuth oxo-selenite bromide

    A new bismuth oxo-selenite bromide Bi6(SeO3)3O5Br2 was synthesized and structurally characterized. The crystal structure belongs to the triclinic system (space group P1-bar , Z=2, a=7.1253(7) Å, b=10.972(1) Å, c=12.117(1) Å, α=67.765(7)°, β=82.188(8)°, γ=78.445(7)°) and is unrelated to those of other known oxo-selenite halides. It can be considered as an open framework composed of BiOx or BiOyBrz polyhedrons forming channels running along [1 0 0] direction which contain the selenium atoms in pyramidal shape oxygen coordination (SeO3E). The spectroscopic properties and thermal stability were studied. The new compound is stable up to 400 °C. - graphical abstract: New bismuth oxo-selenite bromide with new open framework structure. Highlights: ► New bismuth oxo-selenite bromide was found and structurally characterized. ► Bi6(SeO3)3O5Br2 exhibit a new open framework structure type. ► BiOx or BiOyBrz polyhedrons form channels in the structure which are decorated by [SeO3E] groups.

  1. Delivery of albuterol and ipratropium bromide from two nebulizer systems in chronic stable asthma. Efficacy and pulmonary deposition

    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

  2. Elastic silicone encapsulation of n-hexadecyl bromide by microfluidic approach as novel microencapsulated phase change materials

    Highlights: • n-Hexadecyl bromide was encapsuled in elastic silicone shell. • The surfaces of microcapsules were smooth and the cross sections were compact. • Latent heat of microcapsules was 76.35 J g−1. • The microencapsulation ratio was 49 wt.%. • The microcapsules had good thermal stability. - Abstract: The elastic silicone/n-hexadecyl bromide microcapsules were prepared as novel microencapsulated phase change materials by microfluidic approach with the co-flowing channels, where the double oil1-in-oil2-in-water (O1/O2/W) droplets with a core–shell geometry were fabricated. The thermal characterizations of the microcapsules were investigated using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The DSC results showed that the microcapsules had good energy storage capacity with melting and freezing enthalpies 76.35 J g−1 and 78.67 J g−1, respectively. The TGA investigation showed that the microcapsules had good thermal stability. The surfaces of microcapsules were smooth and the cross sections were compact from the results of optical microscope and scanning electron microscopy (SEM). Optical microscope showed that the silicone shell can provide expansion place due to its elastic property. Therefore, the silicone/n-hexadecyl bromide microcapsules showed good potential as thermal regulating textile and thermal insulation materials

  3. Mechanism of separation of uranium(VI) by flotation from dilute carbonate and sulfate solutions with the aid of alkylpyridinium bromides

    In this paper, the authors present the results of experiments carried out for elucidation of the principal relationships of the process, for flotation of uranyl carbonate and sulfate complexes, collected from dilute aqueous solutions with the aid of tetradecylpyridinium (TDPB), pentadecylpyridinium (PDPB), and hexadecylpyridinium (HDPB) bromides. Flotation of complex uranium anions collected from carbonate solutions with the aid of alkylpyridinium bromides proceeds in absence of an energy barrier of repulsion between the sublate particles and air bubbles

  4. On metal oxide solubilities in some molten alkali metal bromides at T = 973 K

    Highlights: • Solubility products of MeO oxides in KBr–NaBr and KBr–LiBr eutectics are presented. • Correlation between radius of cation entering in oxide and its solubility is found. • Melt acidity increases in CsBr − KBr → KBr − NaBr → KBr − LiBr sequence. • The common oxoacidity scale of alkali metal chlorides and bromides is constructed. - Abstract: Reactions of Me2+ cations with O2− in molten (KBr + NaBr) (0.5:0.5) and (KBr + LiBr) (0.4:0.6) mixtures at T = 973 K were studied by potentiometric titration method using Pt(O2)|ZrO2(Y2O3) indicator electrode. In the former melt, the set of cations available for investigation was wide enough (Me = Sr, Ca, Mn, Co, Ni and Pb) and the corresponding solubility product indices (pKs,MeO, molalities) were found to be (3.81 ± 0.3) (SrO), (5.00 ± 0.3) (CaO), (7.85 ± 0.3) (MnO), (8.80 ± 0.1) (CoO), (9.72 ± 0.04) (NiO) and (5.20 ± 0.3) (PbO). A correlation between pKs,MeO and the polarisation action of the metal cation by Goldschmidt (ZerMe2+-2) was obtained. The oxide solubilities on the mole fraction scale were shown to be close to those obtained in molten (KCl + NaCl) equimolar mixture. On the basis of the solubility data the oxobasicity index (primary medium effect for oxide ion) for the (KBr + NaBr) melt was estimated as pI{KBr–LiBr} = −0.24. Due to considerable oxoacidic properties of Li+ cation in the molten (KBr + LiBr) eutectic, it was possible to study only three from the above cations (Me = Mn, Co and Ni) and their pKs,MeO values were (4.36 ± 0.2), (5.19 ± 0.05) and (6.25 ± 0.03), respectively. Comparison with the corresponding data for (KBr + NaBr) equimolar mixture showed that the Li+-based melt dissolved all the studied oxides in more extent. On the basis of the data obtained, the oxobasicity index value pI{KBr−LiBr} was estimated as (3.01 ± 0.5), that was close to the similar parameter of the chloride analogue (KCl + LiCl) (3.36). The change of the constituent anion of the

  5. Rearrangement reaction of the hydroxyl group of ω-hydroxy-alkyltriphenyl phosphonium bromides

    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.

  6. Spectroscopic study on the interaction of Bacillus subtilis α-amylase with cetyltrimethylammonium bromide

    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.

  7. The effect of ethidium bromide and chloramphenicol on mitochondrial biogenesis in primary human fibroblasts

    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.

  8. Degradation of methyl bromide by methanotrophic bacteria in cell suspensions and soils

    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.

    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. Aclidinium bromide/formoterol fixed-dose combination therapy for COPD: the evidence to date

    Moitra S

    2015-04-01

    Full Text Available Subhabrata Moitra,1 Arvind B Bhome,2 Bill B Brashier1 1Chest Research Foundation, Pune, Maharashtra, India; 2Indian Coalition of Obstructive Lung Diseases (ICOLD Network, Pune, Maharashtra, India Abstract: The quest for the right combination of bronchodilators with different mechanisms of action such as long-acting muscarinic antagonists and long-acting β-agonists in the management of stable moderate-to-severe chronic obstructive pulmonary disease (COPD is a topic of intense research activity currently, given the rising morbidity and mortality due to this disease. The fixed-dose combination of aclidinium bromide and formoterol fumarate in a single inhaler seems to offer superior advantages over either drugs given alone or as separate inhalers concurrently. Since the fixed-dose combination needs to be given twice daily, it is likely to achieve control of symptoms most crucial to the quality of life in COPD, namely, the morning hours. This is reflected in significant trough FEV1 (forced expiratory volume in 1 second improvements after the dose. This paper reviews the various studies related to this combination put in the perspective of its safety and efficacy and potential benefits over other therapeutic options. However, there is a dearth of data on the long-term safety and efficacy in terms of improvement in lung function. This combination could emerge as an excellent option in the management of stable COPD if data on exacerbation rates and patient-reported outcomes become available from longer-term studies. Moreover, we need some more studies to define the ideal phenotype of COPD best suited for the use of this combination. Keywords: aclidinium, formoterol, COPD, lung function, bronchodilators, combination therapy

  11. Adsorption of hexavalent chromium onto montmorillonite modified with hydroxyaluminum and cetyltrimethylammonium bromide

    Aluminum hydroxypolycation and cetyltrimethylammonium bromide (CTMAB) were chosen to synthesize inorganic-organic pillared montmorillonite. Three different methods were employed for the intercalation. The characteristics of natural and modified montmorillonite were determined with X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), X-ray photoelectron spectrum (XPS), and zeta potential. It was found that aluminum hydroxypolycation and CTMAB had either entered the interlayer or sorbed on the external surface of the clay. Different intercalation orders can result in different structures. Batch adsorption of hexavalent chromium (Cr6+) onto modified montmorillonite was also investigated. The experimental data revealed that if aluminum hydroxypolycation was intercalated before CTMAB, the adsorption capacity was better than that of intercalated simultaneously or CTMAB pre-intercalated. The pH of the solution and environmental temperature had significant influences on the adsorption of Cr6+. The optimal pH for the removal was about 4, and the temperature of 298 K was best suitable. All adsorption processes were rapid during the first 5 min and reached equilibrium in 20 min. The adsorption kinetics can be described quite well by pseudo-second-order model. The adsorption rates of ACM, CAM and ACCOM were 3.814, 0.915, and 3.143 mg/g/min, respectively. The adsorption capacities of Cr6+ at 298 K on ACM, CAM, and ACCOM inferred from the Langmuir model were 11.970, 6.541, and 9.090 mg/g, respectively. The adsorption of Cr6+ on modified montmorillonite was mainly induced by the surface charge and the complexation reaction between CTMA+ and hexavalent chromium species at the edge of the clay particle.

  12. The effect of ethidium bromide and chloramphenicol on mitochondrial biogenesis in primary human fibroblasts

    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.

  13. Structure and scintillation of Eu{sup 2+}-activated calcium bromide iodide

    Gundiah, Gautam, E-mail: GGundiah@lbl.gov; Gascón, Martin; Bizarri, Gregory; Derenzo, Stephen E.; Bourret-Courchesne, Edith D.

    2015-03-15

    We report the structure and scintillation properties of Eu{sup 2+}-activated calcium bromide iodide. CaBr{sub 0.7}I{sub 1.3} was the only composition that could be synthesized in the CaBr{sub 2}–CaI{sub 2} system. The compound has an effective atomic number of 47 and crystallizes in a trigonal crystal system with the R-3 space group and a density of 3.93 g/cc. The structure is layered and contains Ca in an octahedral environment with the Br/I anions jointly occupying a single site. Eu{sup 2+}-activated samples show an intense narrow emission, characteristic of the 5d–4f transition of Eu{sup 2+}, when excited with UV or X-rays. The sample with 0.5% Eu shows a light output of 63,000 ph/MeV at 662 keV with 96% of the light emitted with a monoexponential decay time of 1332 ns. An energy resolution of 10.4% full width at half maximum (FWHM) has been achieved for 662 keV gamma rays at room temperature. - Highlights: • CaBr{sub 0.7}I{sub 1.3} is the only composition that formed in the CaBr{sub 2}–CaI{sub 2} system. • Crystallizes in a trigonal crystal system with the R-3 space group. • Eu{sup 2+}-activation yields scintillator with bright blue emission centered at 465 nm. • Light output is 63,000 ph/MeV with 10.4% energy resolution at 662 keV. • Monoexponential decay time of 1332 ns.

  14. Calcium chloride and calcium bromide aqueous solutions of technical and analytical grade in Lemna bioassay.

    Vujević, M; Vidaković-Cifrek, Z; Tkalec, M; Tomíc, M; Regula, I

    2000-11-01

    Saturated water solutions of calcium chloride, calcium bromide and their 1:1 mixture are commonly used as "high density brines" for pressure control in oil wells. To compare the effect of these chemicals of technical grade with the effect of the chemicals of analytical grade the Lemna test was used. The multiplication rate, fresh weight, dry to fresh weight ratio, area covered by plants and chlorophyll content were measured as toxicity parameters. The concentrations of tested chemicals were 0.025, 0.05. 0.075 and 0.1 mol dm(-3). Generally, the chemicals of both technical and analytical grade in concentrations of 0.025 mol dm(-3) stimulated the Lemna minor growth, while tested chemicals in concentrations of 0.05 mol dm(-3) did not affect the growth significantly. The exceptions were results obtained by measuring fresh weight. Most of tested chemicals in concentrations of 0.075 mol dm(-3) and all chemicals in concentrations of 0.1 mol dm(-3) reduced the growth. No major differences between effects of tested chemicals of technical and analytical grade on plant growth were observed, except that tested chemicals of analytical grade in concentrations of 0.1 mol dm(-3) increased dry to fresh weight ratio much stronger than chemicals of technical grade. All tested chemicals in all concentrations increased chlorophyll content. After treatment with chemicals of analytical grade much higher increase of chlorophyll a concentration in comparison to increase of chlorophyll b was noticed, while chemicals of technical grade caused more prominent increase of chlorophyll b. PMID:11057678

  15. Antibacterial activity of starch/acrylamide/allyl triphenyl phosphonium bromide copolymers synthesized by gamma irradiation

    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

  16. Application of artificial neural network in 3D imaging with lanthanum bromide calorimeter

    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.

  17. Hydrophobic Ion-Pairing of Low Molecular Weight Heparin with Cetyltrimethylammonium Bromide

    Nermin E. Eleraky

    2015-03-01

    Full Text Available Purpose: Unfavorable physicochemical properties of low molecular weight heparin (LMWH restrict membrane permeation of this therapeutic macromolecule to paracellular passive diffusion. To augment LMWH flux across biological membranes using contributions of transcellular transport mechanisms, this study explored formation of electrostatically stabilized association complexes via ion-pairing with the lipophilic cetyltrimethylammonium bromide (CTAB. Methods: LMWH/CTAB interactions were assessed in acetate buffer, pH 5.0, using molar ratios ranging from 1:0 to1:40. Unbound LMWH was quantified spectrophotometrically at λ=630 nm using the Azure A assay. Dynamic laser light scattering technology was applied to estimate hydrodynamic diameter and zeta potential of electrostatically stabilized LMWH/CTAB association complexes. Results: Unbound LMWH concentrations significantly decreased from 95.9±2.3% to 14.4±2.6% in the presence of CTAB at a molar ratio of at least 1:30. In parallel, formation of colloidal association complexes was detected exhibiting mean hydrodynamic diameters between 400-500 nm and maximum zeta potential values of +1.85±0.80 mV. Using Job’s continuous variation method, a 1:1 stoichiometry of LMWH/CTAB association complexes in acetate buffer, pH 5.0, was concluded. Benesi-Hildebrand and Scatchard transformations of experimental binding data revealed an estimated formation constant for LMWH/CTAB complexes at pH 5 of 1.1×10-7 and 1.2×10-7L×mol-1, respectively. Conclusion: The results from this study suggest weak ion-pairing between LMWH and CTAB in acetate buffer, pH 5.0. The slightly positively charged nanocomplex is predicted to access transcellular transport mechanisms more effectively than the highly negatively charged LMWH. As a consequence, electrostatically stabilized LMWH/CTAB association complexes may enhance overall permeation properties of LMWH across biological membranes.

  18. Spectroscopic study on the interaction of Bacillus subtilis {alpha}-amylase with cetyltrimethylammonium bromide

    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. Spectroscopic study of neodymium doped potassium lead bromide for mid-infrared solid state lasers

    We present spectroscopic results of the mid-infrared (MIR) emission (4I11/2→4I9/2) properties of neodymium (Nd) doped potassium lead bromide (KPb2Br5). Following optical excitation at either 0.808 or 0.89 μm, Nd:KPb2Br5 showed a broad MIR emission band centered at 5.25 μm with a bandwidth of 0.76 μm at full width half maximum. For low concentration samples (5×1018 cm−3), the emission lifetime was determined to be 43 ms at room temperature and increased to 57 ms at low temperature (15 K). Based on the energy-gap law, non-radiative decay through multi-phonon relaxation is predicted to be negligibly small in this low phonon energy host material with ℏωmax=138 cm−1. Therefore, the modest temperature dependence of the MIR lifetime is most likely due to the existence of non-radiative decay related to residual defects in the sample. The peak emission cross-section for the 4I11/2→4I9/2 transition was determined to be 0.65×10−20 cm2. Some comparative results on Nd:KPb2Cl5 were also included in this study. - Highlights: ► Nd doped KPb2Br5 crystal was grown by the horizontal Bridgman technique. ► Observed broad emission at 5.25 μm with a long lifetime of 43 ms at room temperature. ► Some comparative results on Nd:KPb2Cl5 were also studied. ► The mid-infrared laser potential and other laser relevant parameters were discussed.

  20. Temperature effect on the transport of bromide and E. coli NAR in saturated soils

    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.

  1. Performance characteristics of single effect lithium bromide/ water absorption chiller for small data centers

    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

  2. CdTe quantum dots functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide as luminescent nanoprobe for the sensitive recognition of bromide ion

    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.

  3. Once-daily glycopyrronium bromide, a long-acting muscarinic antagonist, for chronic obstructive pulmonary disease: a systematic review of clinical benefit

    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

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

    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.

  5. Formation of bromate during ferrate(VI) oxidation of bromide in water.

    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

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

    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.

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

    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

  8. Titrimetric, spectrophotometric and kinetic methods for the assay of atenolol using bromate–bromide and methyl orange

    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. Effect of cationic composition of the medium on ruthenium(4) complexing with chloride- and bromide-ions

    Spectrophotometric method was used to study the process of substitution of chloride- and bromide-ions for water molecules in ruthenium(4) aqua complex in different media and in wide range of ligand concentrations (0.02-11 mol/l). Substitution of cation of background electrolyte in Na-Li-H series results to the shift of equilibrium of the reaction of Ru(4) chloro-and bromocomplex formation to the side of formation of complex forms, characterized by higher coordination saturation with halide-ions

  10. Non-conservative behavior of bromide in surface waters and brines of Central Andes : a release into the atmosphere ?

    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...

  11. Spectrophotometric determination of trace quantities of iodide after separation from large quantities of bromide, chloride, or sulfate by solvent extraction

    Iodide solutions were reacted with 2,4,6-triphenylpyrylium bisulfate to yield the triphenylpyrylium iodide which was extracted with chloroform and spectrophotometrically determined. The interference from perchlorate, bromide, chloride, and sulfate ions on the iodide determination was evaluated. An analytical procedure for the determination of iodide present as the iodate was developed using sodium sulfite to reduce the iodate to iodide. The use of this method for the determination of KI in commercial iodized salt gave results comparable to those obtained by the AOAC iodometric method. (U.S.)

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

    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.

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

    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

  14. Chemical distribution factors of microimpurities in triethyl indium synthesis from indium-magnesium alloy and ethyl bromide

    The experimental determination of chemical coefficients of separation of a row of microimpurities (Zn, Cd, Al, Ga, Si, Pb, Sn, Sb, Bi, Fe, Mg, Mn, Ni, Cu, Ag) is carried out in the process of preparing triethylindium out of the Mg - In alloy and ethyl bromide in the medium of diethyl ester. It is stated that impurities of analogous elements, as well as Zn are most difficult for removal. The purity of the final product depends upon the content of impurities in initial metals. The reduction of their content in the alloy leads to the decrease in their concentration in triethylindium. Rectification seems to be one of the most perspective methods of purification

  15. 1-Carboxymethyl-1′-carboxylatomethyl-3,3′-[p-phenylenebis(oxymethylene]dipyridinium bromide dihydrate

    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.

  16. Preparation of a chitosan-based anionic exchanger for removal of bromide, chloride, iodide and phosphate ions from aqueous solutions

    Affonso Celso Gonçalves Júnior

    2014-02-01

    Full Text Available The development of a chitosan anion exchanger, obtained from shrimp shells, and its adsorption capacity for chloride, bromide, iodide and phosphate anions are provided. Dependence of exchange processes with the anions as a function of pH and contact time between exchanger and anions were initially investigated. Results showed that the best adsorption of ions occurred at pH 3.0. Exchange isotherms were then developed by the Langmuir, Freundlich and Dubinin-Radushkevich mathematical models. Results demonstrated that chitosan produced from shrimp shells may be used as feedstock in the manufacture of anion exchange microspheres.

  17. Efficacy and safety of eco-friendly inhalers: focus on combination ipratropium bromide and albuterol in chronic obstructive pulmonary disease

    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

  18. The effect of cetyltrimethylammonium bromide on size and morphology of ZnO and CuO

    Subba Rao, Anantha N.; Venkatarangaiah, Venkatesha T.

    2014-01-01

    The nanoparticles (NP) ZnO and CuO were synthesized by electrochemical-thermal method. The influence ofcetyltrimethylammonium bromide (CTAB) on size and morphology of NP was evaluated. They were characterized by powder X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), UV-Visible absorption spectroscopy. The average crystallite size and the average grain size of NP decreased with CTAB concentration. The CTAB significantly affected the morphology of CuO and ZnO NP. The r...

  19. Study of the Ion Channel Behavior of Didodecyldimethylammonium Bromide Formed Bilayer Lipid Membrane Stimulated by PF-6

    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.

  20. Role of intravenously administered hyoscine butyl bromide in retrograde terminal ileoscopy: A randomized, double-blinded, placebo-controlled trial

    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.

  1. Triazolyl blue tetrazolium bromide as a novel corrosion inhibitor for steel in HCl and H2SO4 solutions

    Research highlights: → Triazolyl blue tetrazolium bromide (TBTB) is found to be a novel good inhibitor for the corrosion of CRS in 1.0 M HCl and 0.5 M H2SO4 solutions. → The comparison of inhibition performance in HCl and that in H2SO4 are discussed in detail. → The corrosion inhibition is satisfactorily discussed by adsorption mode and thermodynamic parameter. → The electrochemical inhibitive mechanism is explained by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) results. → The adsorption of TBTB is presented. - Abstract: The inhibition effect of triazolyl blue tetrazolium bromide (TBTB) on the corrosion of cold rolled steel (CRS) in 1.0 M HCl and 0.5 M H2SO4 solution was investigated for the first time by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that TBTB is a very good inhibitor, and is more efficiency in 1.0 M HCl than 0.5 M H2SO4. The adsorption of TBTB on CRS surface obeys Langmuir adsorption isotherm. Polarization curves reveal that TBTB acts as a mixed-type inhibitor in both acids.

  2. Recent actions taken on methyl bromide under the Montreal Protocol: Their potential economic implications on international trade

    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

  3. Synthesis, crystal growth and spectroscopic investigation of novel metal organic crystal: β-alanine cadmium bromide monohydrate (β-ACBM).

    Renugadevi, R; Kesavasamy, R

    2014-07-15

    β-Alanine cadmium bromide monohydrate (β-ACBM), a new metal organic crystal has been grown from aqueous solution by slow evaporation technique. The grown crystals have been subjected to single crystal X-ray diffraction analysis to determine the crystal structure. The β-ACBM crystallized in monoclinic system with space group P2(1)/c. The presence of protons and carbons in the β-alanine cadmium bromide monohydrate was confirmed by (1)H and (13)C nuclear magnetic resonance spectral analysis. The mode of vibration of different molecular groups present in β-ACBM was identified by FT-IR spectral analysis. Transparency of crystals in UV-Vis-NIR region has also been studied. The thermal characteristics of as-grown crystals were analyzed using thermo gravimetric and differential thermal analyses. The magnetic property of the grown crystal was investigated using Vibrating Sample Magnetometer (VSM) at ambient temperature. The mechanical stability of β-ACBM was evaluated by Vickers microhardness measurement. PMID:24691377

  4. Combined effect of gamma radiation and methyl bromide fumigation on the confused flour beetle, tribolium confusum, DUV

    A laboratory study was carried out in egypt to determine the effect of combining treatments of gamma radiation and methyl bromide fumigation applied to to adults of tribolium confusum (D uv.) An interaction between radiation and insecticidal treatment was obvious, with additive effects noted at most combination treatments. When radiation treatments were applied first and followed by fumigation within 24 hr, very low dosages of radiation (2-6 krad) decreased the susceptibility of the insects to marginally effective dosages of methyl bromide after 14 days. Irradiation pretreatment followed by fumigation after 21 days enhanced the fumigant effectiveness. Irradiation treatments using dosages from 5-50 krad followed by fumigant treatments after 7 days killed more insects than did either treatment applied alone. When sublethal dosages of fumigation preceded irradiation, the insects became more radio-sensitive. In general, the effects of irradiation and fumigation combinations were higher than the effects of either treatment given singly, irrespective which treatment was given first. 3 tab

  5. Linear optical properties and their bond length dependence of yttrium bromide from ab initio and density functional theory calculations

    Graphical abstract: The electronic properties such as the static dipole polarizability, anisotropy of the polarizability, and dipole moment of yttrium bromide, YBr (X1Σ) have been theoretically studied. Highlights: → Conventional ab initio and density functional theory methods were employed to study linear optical properties of YBr molecule. → Properties derivatives and their level of theory dependence were studied. → 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, α-bar, anisotropy of the polarizability, Δα, and dipole moment, μ, 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.

  6. Viscometric studies of interactions between ionic liquid 1-octyl-3-methyl-imidazolium bromide and polyvinyl pyrrolidone in aqueous solutions

    Highlights: • Viscosities of PVP in aqueous solution of IL are measured. • The flow activation energies are calculated. • The flow activation energies are correlated in terms of polymer concentration. • Intrinsic viscosity of PVP is decreased by increasing temperature. - Abstract: Ionic liquids are investigated as solvents for polymerization processes, as plasticizers of various kinds of polymers and as components of the polymeric matrixes. In this research, viscosity of polyvinyl pyrrolidone in aqueous solution of ionic liquid, 1-octyl-3-methyl imidazolium bromide are measured at various temperatures. The flow activation energies are calculated and correlated in terms of polymer concentration. From sign of the initial slope of the activation energy versus polymer concentration at zero concentration, it is concluded that thermodynamic quality of ionic liquid aqueous solutions are reduced by increasing temperature. The value of the intrinsic viscosity of polyvinyl pyrrolidone was determined using Huggins equation and thermodynamic parameters of this polymer were calculated on the basis of intrinsic viscosity. Also the effect of ionic liquid, 1-octyl-3-methyl imidazolium bromide on the thermodynamic parameters of dilute aqueous polyvinyl pyrrolidone solutions, such as (polymer + solvent) interaction parameter, theta temperature, the heat of dilution parameter and the entropy of dilution parameter was investigated. Results suggest that the thermodynamic quality of water was increased slightly by the addition of ionic liquid in aqueous solution of polyvinyl pyrrolidone

  7. The Efficacy and Safety of Topical Rocuronium Bromide to Induce Bilateral Mydriasis in Hispaniolan Amazon Parrots ( Amazona ventralis ).

    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. High-performance liquid chromatographic assay for the simultaneous determination of ipratropium bromide, fenoterol, salbutamol and terbutaline in nebulizer solution.

    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

  9. Photoinduced Dissociation Of N-alkyl Bromides On Gallium Arsenide(110) And Gallium Arsenide(100) Electron And Fragment Dynamics

    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...

  10. Interaction between dodecyl oxypropyl β-hydroxyltrimethylammonium bromide and Xanthan: MesoDyn simulation and binding isotherm measurements

    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. Influence of alkyl chain on the thermodynamic properties of aqueous solutions of ionic liquids 1-alkyl-3-methylimidazolium bromide at different temperatures

    Osmotic coefficients φ, mean activity coefficients γ±, vapor pressure p data, and excess Gibbs free energies GE of aqueous solutions of three ionic liquids 1-propyl-3-methylimidazolium bromide [PMIm]Br, 1-pentyl-3-methylimidazolium bromide [PnMIm]Br, and 1-hexyl-3-methylimidazolium bromide [HMIm]Br were determined by the vapor pressure osmometry method at four temperatures (298.15 K to 328.15 K) in intervals 10 K. From the comparison of osmotic coefficients it follows that aqueous solution of [PMIm]Br shows a more pronounced deviation from Debye-Hueckel limiting law (DHLL) and vapor pressure depression more than the other studied ionic liquids which was interpreted in terms of hydrophobic interactions. The Pitzer-ion interaction and MNRTL electrolyte models satisfactorily correlate experimental osmotic coefficient data with good precision. The parameters of the Pitzer-ion interaction model are used to calculate the mean molal activity coefficients and excess Gibbs free energies

  12. Biological half-life of xenobiotic bromide in the rat is dependent on sodium intake and varies with the metabolic activity of the animals

    In the present study, we extended the applicability of our experimentally proved hypothesis. In the rats situated in very different physiological states, as regards their metabolic activity, we investigated variations in the biological half-life of bromide (as a substitute for sodium) with the aid of in vivo whole-body counting of the animals, administered simultaneously with the radionuclides 82Br and 24Na, by high-resolution gamma-ray spectrometry. The excretion rates of bromide were measured in animals situated in different physiological states. The shortest biological half-life of bromide/sodium ions (44 h) was determined in lactating dams and the longest (269 h) in breast-fed pups. The measured values demonstrate that lactating dams obviously waste sodium, due to their large food intake, whereas sucklings apparently conserve sodium, because of its relatively low concentration in breast milk. (author)

  13. Chlorination of bromide-containing waters: Enhanced bromate formation in the presence ofsynthetic metal oxides and deposits formed indrinking water distribution systems

    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.

  14. Development of a miniature dielectric barrier discharge–optical emission spectrometric system for bromide and bromate screening in environmental water samples

    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

  15. Oxidation of 3,5-dibromo-4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl to oxoammonium bromide carried out through radiolysis of CHCl3

    Using radiolysis of chloroform, 3,5-dibromo-4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl (1) is oxidized to its corresponding oxoammonium bromide (3). The mechanism is a one electron oxidation forming the oxoammonium ion (3) which is stabilized by a bromide counter ion. Br- is generated through a one-electron reduction of (1) resulting in a Br- loss and the formation of a second product. The reaction is quantitative. Compound (3) which is non paramagnetic is easily studied by NMR and gives access to the structure of (1). Radiolysis then reveals to be a highly selective oxidation process. (author) 18 refs.; 2 figs

  16. Bromide and other ions in the snow, firn air, and atmospheric boundary layer at Summit during GSHOX

    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.

  17. Bromide and other ions in the snow, firn air, and atmospheric boundary layer at Summit during GSHOX

    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.

  18. Sodium bromide-cesium bromide-calcium bromide system

    Fusibility diagram of Na2Br2-Cs2Br2-CaBr2 system is investigated. System liquidus consists of crystallization fields of components and congruently melting CaBr2xCsBr compound. The main triangle is devided by CaBr2xCsBr-Na2Br2 cross-section into two coordinated phase triangles with eutectic points at 460 and 490degC

  19. CO2 capture from binary mixture via forming hydrate with the help of tetra-n-butyl ammonium bromide

    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.

    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. Evaluation of the combination of dimethyl disulfide and dazomet as an efficient methyl bromide alternative for cucumber production in China.

    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

  2. Interaction of Lucifer yellow with cetyltrimethyl ammonium bromide micelles and the consequent suppression of its non-radiative processes

    Mishra, Padmaja P.; Koner, Apurba L.; Datta, Anindya

    2004-12-01

    The interaction of the fluorophore Lucifer yellow with micelles has been monitored using steady state and time resolved fluorescence techniques. Contrary to the popular belief that the fluorophore is too polar to associate with the stern layer or hydrophobic core of micelles, we have observed that it binds with the micelles of the positively charged surfactant cetyl trimethyl ammonium bromide and that such interaction causes an decrease in the rates of its non-radiative processes. This phenomenon cannot be explained solely in the light of a reduced polarity, as we have demonstrated that the photophysics of Lucifer yellow is complex and intramolecular charge transfer does not seem to be the only excited state process that is operative.

  3. Purification of Zinc Bromide Solution used as shield in hot cells windows for handling of highly radioactive sources

    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)

  4. Physicochemistry of hexadecylammonium bromide and its methyl and ethanolic head group analogues in buffered aqueous and gelatin solution

    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. Unilateral pupillary mydriasis from nebulized ipratropium bromide: A false sign of brain herniation in the intensive care unit

    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.

  6. Crystal structure of 2-bromo-3-dimethylamino-N,N,N′,N′,4-pentamethyl-4-(trimethylsilyloxypent-2-eneamidinium bromide

    Ioannis Tiritiris

    2015-12-01

    Full Text Available The reaction of the orthoamide 1,1,1-tris(dimethylamino-4-methyl-4-(trimethylsilyloxypent-2-yne with bromine in benzene, yields the title salt, C15H33BrN3OSi+·Br−. The C—N bond lengths in the amidinium unit are 1.319 (6 and 1.333 (6 Å, indicating double-bond character, pointing towards charge delocalization within the NCN plane. The C—Br bond length of 1.926 (5 Å is characteristic for a C—Br single bond. Additionally, there is a bromine–bromine interaction [3.229 (3 Å] present involving the anion and cation. In the crystal, weak C—H...Br interactions between the methyl H atoms of the cation and the bromide ions are present.

  7. A kinetic study of the thermal degradation of cetyltrimethylammonium bromide inside the mesoporous SBA-3 molecular sieve

    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.

  8. Transport of bromide and pesticides through an undisturbed soil column: a modeling study with global optimization analysis.

    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

  9. Thermophysical properties of ionic liquid {1-butyl-3-methylimidazolium bromide [bmim][Br] in alkoxyalkanols + water} mixtures at different temperatures

    Highlights: ► Densities and speeds of sound of alkoxyalkanols in [bmim][Br]. ► Synthesis of room temperature ionic liquid [bmim][Br]. ► Partial molar volumes and compressibility of transfer. ► Apparent molar expansivities and the Hepler’s constant were calculated. ► Solute–solute and solute–solvent interactions and the structural changes of the solutes. - Abstract: The interactions of alkoxyalkanols with the ionic liquid 1-butyl-3-methylimidazolium bromide [bmim][Br] as a function of temperature were investigated by combination of volumetric and acoustic methods. The density, ρ, and speed of sound, u, of ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, and triethylene glycol monomethyl ether (0.00–1.01 mol·kg−1) in aqueous 1-butyl-3-methylimidazolium bromide solutions ranging from pure water to 0.29 mass% of ionic liquid have been measured at T = (288.15, 298.15 and 308.15) K and atmospheric pressure. The apparent molar volume (Vφ) and adiabatic compressibility (Kφ,S) of alkoxyalkanols in aqueous ionic liquid solution were determined at the measured temperatures. The partial molar volume (Vφ0) and partial molar adiabatic compressibility (Kφ0) of alkoxyalkanols at infinite dilution were evaluated. Transfer volumes (ΔVφ0) and transfer adiabatic compressibility (ΔKφ0) at infinite dilution from water to aqueous ionic liquid solution were also calculated. The temperature dependence of the apparent molar volume was used to calculate apparent molar expansivity (φE0) and the Hepler’s constant values, (∂2Vφ0/∂T2). The results were explained on the basis of competing patterns of interactions of co-solvent and the solute.

  10. Dissociation behaviour of (tetra-n-butylammonium bromide + tetra-n-butylammonium chloride) mixed semiclathrate hydrate systems

    Highlights: • Thermal properties of (TBAB + TBAC) mixed hydrates were studied. • Dissociation temperatures and enthalpies exceeded those of pure hydrates. • Crystal systems of the mixed hydrates were comparable to those of pure hydrates. • Mixed hydrates showed small crystal distortion and hence large hydration numbers. • (TBAB + TBAC) mixed hydrates may be useful in thermal storage and gas transport. - Abstract: The thermal properties of {tetra-n-butylammonium bromide + tetra-n-butylammonium chloride (TBAB + TBAC)} mixed semiclathrate hydrates prepared from aqueous solutions were investigated by dissociation temperature measurements and differential scanning calorimetry (DSC). The maximum dissociation temperature of the mixed hydrate crystals at 0.1 MPa is 288.5 K for xTBAB = 0.2 {mole fraction of TBAB to (TBAB + TBAC)}, which is higher than that of the pure hydrates {T = (285.5 and 288.2) K for TBAB and TBAC hydrates, respectively}. In addition, the dissociation enthalpies of the mixed hydrates are higher than those of the pure hydrates {(5.55 ± 0.06) kJ ⋅ mol−1 H2O for pure TBAB hydrate and (5.30 ± 0.05) kJ ⋅ mol−1 H2O for pure TBAC hydrate}, with a maximum of (5.95 ± 0.12) kJ ⋅ mol−1 H2O recorded at approximately xTBAB = 0.4. It was therefore suggested that the crystal distortion in (TBAB + TBAC) mixed hydrates, caused by replacing water molecules by both bromide and chloride anions, was smaller than that observed for each pure hydrate. Consequently, the hydration numbers in the mixed hydrates were hypothesized to be slightly higher than those of the pure hydrates

  11. Transport of bromide and pesticides through an undisturbed soil column: A modeling study with global optimization analysis

    Dusek, Jaromir; Dohnal, Michal; Snehota, Michal; Sobotkova, Martina; Ray, Chittaranjan; Vogel, Tomas

    2015-04-01

    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 cm3 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.

  12. Pharmacoeconomic evaluation of tiotropium bromide in the long-term treatment of chronic obstructive pulmonary disease (COPD) in Italy.

    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. Long-term efficacy and safety of otilonium bromide in the management of irritable bowel syndrome: a literature review

    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

  14. Effects of reduced rates of Telone C35 and methyl bromide in conjunction with virtually impermeable film on weeds and root-knot nematodes

    Two field trials were conducted in Florida in 2004 to test the efficacy of reduced rates of the fumigants methyl bromide and 1,3-dichloropropene (1,3-D) plus chloropicrin in combination with virtually impermeable film (VIF) and standard low density polyethylene (LDPE) film. In spring grown tomato, ...

  15. Biological half-life of xenobiotic bromide in the rat is dependent on sodium intake and varies with the metabolic activity of the animals

    Pavelka, Stanislav

    Bratislava : Slovak University of Technology, 2013, s. 232-235. ISBN 978-80-227-3959-7. [Industrial Toxicology 2013 /33./. Svit, Vysoké Tatry (SK), 19.06.2013-21.06.2013] Institutional support: RVO:67985823 Keywords : bromide * sodium intake * biological half-life Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  16. Synthesis and characterization of [BMIM]bromide using microwave-assisted organic synthesis method and its application for dissolution of palm empty fruit bunch

    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

  17. 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

    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...

  18. Effect of emepronium bromide (Cetiprin) on symptoms and urinary bladder function after transurethral resection of the prostate. A double-blind randomized trial

    Bonnesen, T; Tikjøb, G; Kamper, A L; Nielsen, A M; Andersen, J T; Jørgensen, S J

    1984-01-01

    75 patients were randomized to be treated with either emepronium bromide (Cetiprin) 200 mg 4 times a day or placebo after transurethral resection of the prostate. The patients were evaluated urodynamically pre- and postoperatively, and further evaluated by micturition symptom charts. No significa...

  19. Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide gemini surfactants as novel corrosion inhibitors for mild steel in formic acid

    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.

  20. Air conditioning using an air-cooled single effect lithium bromide absorption chiller: results of a trial conducted in Madrid in August 2005

    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.)...

  1. Rapid synthesis of an electron-deficient t-BuPHOX ligand: cross-coupling of aryl bromides with secondary phosphine oxides

    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.

  2. Synthesis and characterization of [BMIM]bromide using microwave-assisted organic synthesis method and its application for dissolution of palm empty fruit bunch

    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.

  3. Synthesis and characterization of [BMIM]bromide using microwave-assisted organic synthesis method and its application for dissolution of palm empty fruit bunch

    Arianie, Lucy; Wahyuningrum, Deana; Nurrachman, Zeily; Natalia, Dessy

    2014-03-01

    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.

  4. Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions

    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.

  5. Comparison of efficacy combination of inhaled phormoterol / budesonide turbuhaler vs. combination of nebulized salbutamol / ipratropium bromide on moderate asthma acute exacerbation in Persahabatan Hospital

    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

  6. Palladium-phosphinous acid complexes catalyzed Suzuki cross-coupling reaction of heteroaryl bromides with phenylboronic acid in water/alcoholic solvents

    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.

  7. A sensitive electrochemical chlorophenols sensor based on nanocomposite of ZnSe quantum dots and cetyltrimethylammonium bromide

    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.

  8. Persistent modification of Na{sub v}1.9 following chronic exposure to insecticides and pyridostigmine bromide

    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

  9. A microcalorimetric study of {beta}-cyclodextrin with 3-alkoxyl-2-hydroxypropyl trimethyl ammonium bromides in aqueous solutions

    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.

  10. Bright, stable, and water-soluble CuInS2/ZnS nanocrystals passivated by cetyltrimethylammonium bromide

    Lee, Jun; Han, Chang-Soo

    2015-03-01

    We report a highly bright and stable aqueous dispersion of CuInS2/ZnS (CIS/ZnS) nanocrystals (NCs) using surfactant-assisted microemulsion and cold treatment. CIS/ZnS NCs were facilely synthesized via a stepwise, consecutive hybrid flow reactor approach. To stabilize the optical properties of hydrophobic CIS/ZnS NCs, cetyltrimethylammonium bromide (CTAB) was chosen as a matrix for aqueous phase transfer. As the result, a high quantum yield (QY) of 56.0% and excellent photostability were acquired in aqueous media. For removing excessive surfactants, cold treatment (4°C) of the CTAB-water solution was adopted to prevent further agglomeration of CIS/ZnS NCs, which could secure high stability over 6 months (less 2% reduction in QY). The optical features and structure of the obtained CTAB stabilized CIS/ZnS (CTAB-CIS/ZnS) NCs have been characterized by UV-vis and photoluminescence (PL) spectroscopies, XRD, XPS, EDX, and TEM. The high stability and PL of water soluble CTAB-CIS/ZnS NCs suggest their potential in nanoelectronics and bioapplications.

  11. Adsorption-parallel catalytic waves of cinnamic acid in hydrogen peroxide-tetra-n-butylammonium bromide-acetate system

    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

  12. Improving enzymatic hydrolysis of lignocellulosic substrates with pre-hydrolysates by adding cetyltrimethylammonium bromide to neutralize lignosulfonate.

    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

  13. Pharmacokinetic detection of penicillin excreted in urine using a totally internally reflected resonance light scattering technique with cetyltrimethylammonium bromide.

    Huang, Cheng Zhi; Feng, Ping; Li, Yuan Fang; Tan, Ke Jun

    2005-05-01

    A quantitative analysis method for penicillins including ampicillin (AmP), benzyl penicillin (BP), oxacillin (OA) and amoxycillin (AmO) is proposed that makes use of the totally internally reflected resonance light scattering (TIR-RLS) signal from the penicillin at the H2O/CCl4 interface in the presence of cetyltrimethylammonium bromide (CTMAB), and enables the pharmacokinetics of penicillin taken orally and excreted through urine to be monitored. Penicillin is coadsorbed with CTMAB at the H2O/CCl4 interface in neutral solution, resulting in the formation of ion associates that display greatly enhanced TIR-RLS signals (maximum at 368-372 nm). This enhanced TIR-RLS intensity was found to be proportional to the penicillin concentration over the range 0.2 x 10(-6) to 2.2 x 10(-6) mol L(-1), with limits of determination (3sigma) of 5.0 x 10(-8) to 7.0 x 10(-8) mol L(-1). Pharmacokinetics studies performed using the present method show that the excretion of orally-taken ampicillin through urine has a half-time of 1.05 h and an excremental quantum over 8 h of 49.3%, respectively. PMID:15900456

  14. Removal and degradation of β-lactam antibiotics in water using didodecyldimethylammonium bromide-modified montmorillonite organoclay.

    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

  15. Experimental research on a new solar pump-free lithium bromide absorption refrigeration system with a second generator

    Yaxiu, Gu; Yuyuan, Wu; Xin, Ke [Department of Refrigerating and Cryogenic Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2008-01-15

    This paper is concerned with experimental research on a new solar pump-free lithium bromide absorption refrigeration system with a second generator. By using the second generator together with a lunate thermosiphon elevation tube, the required minimum driving temperature of the heat source is only 68{sup o}C compared to above 100{sup o}C in traditional absorption refrigeration systems. Based on the horizontal-tube falling-film method, the performance of the absorber can be enhanced by the second generator due to an increase in the differential concentration of the solution between the inlet and the outlet of the absorber and an increase in the temperature difference between the inlet and the outlet of the cooling water in the absorber. The yield of condensate with the second generator open is increased by 68% compared to that with the second generator closed. The performance of the evaporator is significantly improved due to the increase in temperature drop of the chilled water and the decrease in the outlet temperature of the chilled water. This leads to an improvement of the performance of the overall refrigeration system. The maximum coefficient of performance (COP) approaches 0.787. (author)

  16. Influence of cetyltrimethylammonium bromide on the morphology of AWO4 (A = Ca, Sr) prepared by cyclic microwave irradiation

    AWO4 (A = Ca, Sr) was prepared from metal salts [Ca(NO3)2.4H2O or Sr(NO3)2], Na2WO4.2H2O and different moles of cetyltrimethylammonium bromide (CTAB) in water by cyclic microwave irradiation. The structure of AWO4 was characterized by X-ray diffraction (XRD) and selected area electron diffraction (SAED). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed the presence of nanoparticles in clusters with different morphologies; spheres, peaches with notches, dumb-bells and bundles, influenced by CTAB. Six Raman vibrational peaks of scheelite structure were detected at 908, 835, 793, 399, 332 and 210 cm-1 for CaWO4 and 917, 833, 795, 372, 336 and 192 cm-1 for SrWO4, which are assigned as ν1(Ag), ν3(Bg), ν3(Eg), ν4(Bg), ν2(Ag) and νf.r.(Ag), respectively. Fourier transform infrared (FTIR) spectra provided the evidence of W-O stretching vibration in [WO4]2- tetrahedrons at 793 cm-1 for CaWO4 and 807 cm-1 for SrWO4. The peaks of photoluminescence (PL) spectra were at 428-434 nm for CaWO4, and 447-451 nm for SrWO4

  17. Evaluation of the effect of tetraethylammonium bromide and chloride on the growth and development of terrestrial plants.

    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

  18. Coal reverse flotation. Part 1. Adsorption of dodecyltrimethyl ammonium bromide and humic acids onto coal and silica

    Marek Pawlik; Janusz S. Laskowski [University of British Columbia, Vancouver, BC (Canada). Department of Mining Engineering

    2003-06-01

    Adsorption of dodecyltrimethyl ammonium bromide (DTAB) and humic acids (HA) on bituminous, oxidized bituminous, and subbituminous coals, as well as on silica, was studied through direct adsorption, electrokinetic, and contact angle measurements. It was concluded that the adsorption of DTAB and HA on a hydrophobic coal surface takes place through hydrophobic interactions between the hydrocarbon chains of these compounds and the hydrophobic coal surface. The adsorbed DTAB molecules cause a gradual decrease of coal hydrophobicity due to their tail-to-surface orientation. The adsorption density of DTAB on a hydrophilic/oxidized coal is much higher than on a bituminous coal. The results indicate that the adsorption mechanism involves some strong interactions between the cationic head group of the surfactant and the negatively charged oxygen groups on the coal surface. Despite the apparent head-to-surface orientation, the adsorbed DTAB molecules do not render the surfaces hydrophobic; this probably results from the fairly chaotic orientation of DTAB molecules on the surface of oxidized coal. The well-ordered conformation of the DTAB ions adsorbed onto the negatively charged silica surface, combined with significant adsorption of this surfactant at the solution/air interface makes the silica surface very hydrophobic.

  19. Three-dimensional model evaluation of the Ozone Depletion Potentials for n-propyl bromide, trichloroethylene and perchloroethylene

    D. J. Wuebbles

    2010-07-01

    Full Text Available The existing solvents trichloroethylene (TCE and perchloroethylene (PCE and proposed solvent n-propyl bromide (nPB have atmospheric lifetimes from days to a few months, but contain chlorine or bromine that could affect stratospheric ozone. Several previous studies estimated the Ozone Depletion Potentials (ODPs for various assumptions for location of nPB emissions, but these studies used simplified modeling treatments. The primary purpose of this study is to reevaluate the ODP for nPB using a current-generation chemistry-transport model of the troposphere and stratosphere. For the first time, ODPs for TCE and PCE are also evaluated. Emissions representing industrial use of each compound are incorporated on land surfaces from 30° N to 60° N. The atmospheric chemical lifetime obtained for nPB is 24.7 days, similar to past literature, but the ODP is 0.0049, lower than in past studies. The derived atmospheric lifetime for TCE is 13.0 days and for PCE is 111 days. The corresponding ODPs are 0.00035 and 0.0060, respectively.

  20. Thermal and structural behavior of dioctadecyldimethylammonium bromide dispersions studied by differential scanning calorimetry and X-ray scattering.

    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.

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

    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.

  2. Structures and Magnetic Properties of Monomeric Copper(II) Bromide Complexes with a Pyridine-Containing Tridentate Schiff Base

    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

  3. Aggregation behavior of 1-dodecyl-3-methylimidazolium bromide in aqueous solution: effect of ionic liquids with aromatic anions.

    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

  4. One-pot synthesis of magnetic hybrid materials based on ovoid-like carboxymethyl-cellulose/cetyltrimethylammonium-bromide templates

    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

  5. Influence of Sodium Bisulfite and Lithium Bromide Solutions on the Shape Fixation of Camel Guard Hairs in Slenderization Process

    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.

  6. Reductive demercuration of hex-5-enyl-1-mercuric bromide by metal hydrides. Rearrangement, isotope effects, and mechanism

    The use of the rearrangement of hex-5-enyl radical intermediates as a mechanistic probe has been examined in the reductive demercurations of hex-5-enyl-l-mercuric bromide (1). Methylcyclopentane and 1-hexene are the major products from reductions of 1 by sodium borohydride, lithium aluminum hydride, and tri-n-butyltin hydride. The formation of methylcyclopentane and the absence of cyclohexane are consistent with a noncage, free-radical chain mechanism for these reductions. The sodium amalgam reduction of 1 produces only 1-hexene. Hex-5-en-l-ol and a peroxide are formed from sodium borohydride reductions of 1 in the presence of molecular oxygen. Isotope effects for transfer of hydrogen to the intermediate hex-5-enyl radicals have been determined from the 1-hexene/methylcyclopentane product ratio, since rearrangement of the 5-hexenyl radical competes with hydrogen abstraction. The magnitude of these isotope effects (1.8 +- 0.2) is the same for reductive demercurations of 1 by sodium borohydride, lithium aluminum hydride, and tri-n-butyltin hydride; these results provide evidence for a common hydrogen-transfer agent, such as hex-5-enyl-1-mercuric hydride, for all of these metal-hydride reductions. The validity of the competing rearrangement method of determining hydrogen isotope effects has been demonstrated by determining the isotope effect for the tri-n-butyltin hydride reduction of 6-bromo-1-hexene (2.8 +- 0.2) at 400C

  7. Significance of physical weathering of two-texturally different soils for the saturated transport of Escherichia coli and bromide.

    Safadoust, A; Mahboubi, A A; Mosaddeghi, M R; Gharabaghi, B; Voroney, P; Unc, A; Khodakaramian, Gh

    2012-09-30

    This study was carried out to investigate the transport of Escherichia coli NAR and bromide (Br) through repacked (R) and weathered (W) soil columns. A suspension containing E. coli NAR and Br were leached and the effluent from the weathered soil columns had greater contaminant concentrations than that from the repacked soil columns. The time to the concentration peak of (C(max)) E. coli NAR and Br increased in the order CL-W HYDRUS-1D software was used to simulate the E. coli NAR and Br transport parameters by inverse modeling. Parameters of the attachment-detachment model were calculated using the dual-permeability model parameters fitted to the BTCs of E. coli NAR. A greater attachment coefficient associated with soil repacking and the finer textured clayey soil demonstrated the importance of adsorbent site and smaller pore spacing in these treatments. Smaller attachment and adsorption isotherm coefficients in weathered soil columns suggest the need for further research to validate this as a predictive model for the risks for vadose zone contaminant transport. PMID:22647706

  8. The effect of cetyltrimethylammonium bromide on size and morphology of ZnO and CuO

    Anantha N. Subba Rao

    2014-09-01

    Full Text Available The nanoparticles (NP ZnO and CuO were synthesized by electrochemical-thermal method. The influence ofcetyltrimethylammonium bromide (CTAB on size and morphology of NP was evaluated. They were characterized by powder X-ray diffraction spectroscopy (XRD, scanning electron microscopy (SEM, UV-Visible absorption spectroscopy. The average crystallite size and the average grain size of NP decreased with CTAB concentration. The CTAB significantly affected the morphology of CuO and ZnO NP. The regular spindle shape of CuO transformed into irregular spherical shape and the homogeneity in the morphology of spherical ZnO NP was lost with increase in CTAB concentration. The effect of morphology and size of ZnO on its photocatalytic activity was evaluated by subjecting methylene blue (MB dye to photocatalytic degradation under the irradiation of UV light. The color removal of MB dye during electrolysis was monitored by UV-Visible spectroscopy. The highest photocatalytic activity was noticed for ZnO 10 mM CTAB.

  9. An experimental integrated absorption heat pump effluent purification system. Pt. 1: Operating on water/lithium bromide solutions

    Santoyo-Gutierrez, S.; Santoyo, E. [Unidad Geotermia (Mexico); Siqueiros, J. [Unidad Energias No-Convencionales (Mexico); Heard, C.L. [Unidad Uso de la Energia Electrica, Inst. de Investigaciones Electricas, Temixco (Mexico); Holland, F.A. [Salford Univ., Overseas Educational Development Office, Salford (United Kingdom)

    1999-05-01

    The merits of single stage absorption heat pumps coupled to simple distillation for effluent treatment are discussed. An experimental integrated absorption heat pump effluent purification system (IAHPEPS) was built and operated with water-lithium bromide as a working mixture. This unit has been used to raise the temperature and hence, the vapour pressure of the impure water contained in one vessel, to the point where pure water vapour will distil from impure effluent solution (tap water or brine) and condense in a second vessel used to collect pure water. Pure effluent production rates of between 0.5 and 4.3 kg h{sup -1} were obtained. The actual coefficient of performance (COP{sub A}) and the heat pump effectiveness varied from 1.1 to 1.4 and 0.58 to 0.72, respectively. The results from the small scale systems indicate the likely results from industrial scale units which could be operated with low quality heat such as waste heat, solar or geothermal resources. (Author)

  10. Study on the enhanced fluorescent spectrum of ciprofloxacin + Al(III) + La(III) + cetyltrimethylammonium bromide system and its application

    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.

  11. Behaviour of a binary solvent mixture constituted by an amphiphilic ionic liquid, 1-decyl-3-methylimidazolium bromide and water Potentiometric and conductimetric studies.

    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. PMID:18969525

  12. A chemical probe technique for the determination of reactive halogen species in aqueous solution: Part 2 – chloride solutions and mixed bromide/chloride solutions

    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.

  13. NIR photoluminescence of bismuth-doped CsCdBr{sub 3} – The first ternary bromide phase with a univalent bismuth impurity center

    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}.

  14. Niobium(v) chloride and imidazolium bromides as efficient dual catalyst systems for the cycloaddition of carbon dioxide and propylene oxide

    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.

  15. Niobium(v) chloride and imidazolium bromides as efficient dual catalyst systems for the cycloaddition of carbon dioxide and propylene oxide

    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.

  16. Initial test results from the RedFlow 5 kW, 10 kWh zinc-bromide module, phase 1.

    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.

  17. Extraction and Chromatographic Determination of Shikimic Acid in Chinese Conifer Needles with 1-Benzyl-3-methylimidazolium Bromide Ionic Liquid Aqueous Solutions

    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...

  18. FTIR Metabolomic Fingerprint Reveals Different Modes of Action Exerted by Structural Variants of N-Alkyltropinium Bromide Surfactants on Escherichia coli and Listeria innocua Cells

    Corte, Laura; Tiecco, Matteo; Roscini, Luca; De Vincenzi, Sergio; Colabella, Claudia; Germani, Raimondo; Tascini, Carlo; Cardinali, Gianluigi

    2015-01-01

    Surfactants are extremely important agents to clean and sanitize various environments. Their biocidal activity is a key factor determined by the interactions between amphiphile structure and the target microbial cells. The object of this study was to analyze the interactions between four structural variants of N-alkyltropinium bromide surfactants with the Gram negative Escherichia coli and the Gram positive Listeria innocua bacteria. Microbiological and conductometric methods with a previously described FTIR bioassay were used to assess the metabolomic damage exerted by these compounds. All surfactants tested showed more biocidal activity in L. innocua than in E. coli. N-tetradecyltropinium bromide was the most effective compound against both species, while all the other variants had a reduced efficacy as biocides, mainly against E. coli cells. In general, the most prominent metabolomic response was observed for the constituents of the cell envelope in the fatty acids (W1) and amides (W2) regions and at the wavenumbers referred to peptidoglycan (W2 and W3 regions). This response was particularly strong and negative in L. innocua, when cells were challenged by N-tetradecyltropinium bromide, and by the variant with a smaller head and a 12C tail (N-dodecylquinuclidinium bromide). Tail length was critical for microbial inhibition especially when acting against E. coli, maybe due the complex nature of Gram negative cell envelope. Statistical analysis allowed us to correlate the induced mortality with the metabolomic cell response, highlighting two different modes of action. In general, gaining insights in the interactions between fine structural properties of surfactants and the microbial diversity can allow tailoring these compounds for the various operative conditions. PMID:25588017

  19. In vitro liver metabolism of aclidinium bromide in preclinical animal species and humans: identification of the human enzymes involved in its oxidative metabolism

    Albertí, Joan J.; Sentellas, Sònia; Salvà, Miquel

    2011-01-01

    Abstract The metabolism of aclidinium bromide, a novel long-acting antimuscarinic drug for the maintenance treatment of chronic obstructive pulmonary disorder, has been investigated in liver microsomes and hepatocytes of mice, rats, rabbits, dogs, and humans. Due to the rapid hydrolysis of this ester compound, two distinct radiolabeled forms of aclidinium were studied. The main biotransformation route of aclidinium was the hydrolytic cleavage of the ester moiety, resulting in the f...

  20. Determination of ACC-induced cell-programmed death in roots of Vicia faba ssp. minor seedlings by acridine orange and ethidium bromide staining

    Byczkowska, Anna; Kunikowska, Anita; Kaźmierczak, Andrzej

    2012-01-01

    Fluorescence staining with acridine orange (AO) and ethidium bromide (EB) showed that nuclei of cortex root cells of 1-aminocyclopropane-1-carboxylic acid (ACC)-treated Vicia faba ssp. minor seedlings differed in color. Measurement of resultant fluorescence intensity (RFI) showed that it increased when the color of nuclear chromatin was changed from green to red, indicating that EB moved to the nuclei via the cell membrane which lost its integrity and stained nuclei red. AO/EB staining showed...