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Sample records for quaternary ammonium chloride

  1. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Quaternary ammonium chloride combination. 172.165 Section 172...Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used...

  2. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Quaternary ammonium chloride combination. 172.165 Section 172...Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used...

  3. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2009-04-01 true Quaternary ammonium chloride combination. 172.165 Section 172...Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used...

  4. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Quaternary ammonium chloride combination. 172.165 Section 172...Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used...

  5. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Quaternary ammonium chloride combination. 172.165 Section 172...Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used...

  6. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Quaternary ammonium chloride combination. 172.165... § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride... the following compounds: n-dodecyl dimethyl benzyl ammonium chloride (CAS Reg. No. 139-07-1);...

  7. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Quaternary ammonium chloride combination. 172.165... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used in food in accordance with...

  8. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Quaternary ammonium chloride combination. 172.165... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used in food in accordance with...

  9. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Quaternary ammonium chloride combination. 172.165... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used in food in accordance with...

  10. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Quaternary ammonium chloride combination. 172.165 Section 172.165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Food Preservatives §...

  11. Hydrolysis of cellulose catalyzed by quaternary ammonium perrhenates in 1-allyl-3-methylimidazolium chloride.

    PubMed

    Wang, Jingyun; Zhou, Mingdong; Yuan, Yuguo; Zhang, Quan; Fang, Xiangchen; Zang, Shuliang

    2015-12-01

    Quaternary ammonium perrhenates were applied as catalyst to promote the hydrolysis of cellulose in 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The quaternary ammonium perrhenates displayed good catalytic performance for cellulose hydrolysis. Water was also proven to be effective to promote cellulose hydrolysis. Accordingly, 97% of total reduced sugar (TRS) and 42% of glucose yields could be obtained under the condition of using 5mol% of tetramethyl ammonium perrhenate as catalyst, 70?L of water, ca. 0.6mmol of microcrystalline cellulose (MCC) and 2.0g of [Amim]Cl as solvent under microwave irradiation for 30min at 150°C (optimal conditions). The influence of quaternary ammonium cation on the efficiency of cellulose hydrolysis was examined based on different cation structures of perrhenates. The mechanism on perrhenate catalyzed cellulose hydrolysis is also discussed, whereas hydrogen bonding between ReO4 anion and hydroxyl groups of cellulose is assumed to be the key step for depolymerization of cellulose. PMID:26318245

  12. Determination of the quaternary ammonium compounds dequalinium and cetylpyridinium chlorides in candy-based lozenges by high-performance liquid chromatography.

    PubMed

    Taylor, R B; Toasaksiri, S; Reid, R G; Wood, D

    1997-09-01

    The retention behavior of the quaternary ammonium compounds benzalkonium chloride, cetylpyridinium chloride and dequalinium chloride on a 100 x 4.6 mm id cyanopropyl stationary phase column is reported as a function of organic modifier and ionic hydrophobic mobile phase additive concentrations. Optimum liquid chromatographic mobile phases using different mobile phase additives are reported which are suitable for the determination of cetylpyridinium chloride and dequalinium chloride in a variety of candy-based lozenge formulations. The quantitative aspects of assays based on the separation of active ingredients and formulation excipients were established. The generality of application of the assay methods was evaluated by determining the quaternary ammonium content of different lozenges and comparing the values obtained with the stated dose. PMID:9374026

  13. 40 CFR 721.10479 - Quaternary ammonium compounds, tris(hydrogenated tallow alkyl)methyl, chlorides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...hydrogenated tallow alkyl)methyl, chlorides. 721.10479 Section 721.10479...hydrogenated tallow alkyl)methyl, chlorides. (a) Chemical substance and significant...hydrogenated tallow alkyl)methyl, chlorides (PMN P-04-335; CAS No....

  14. 40 CFR 721.10479 - Quaternary ammonium compounds, tris(hydrogenated tallow alkyl)methyl, chlorides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...hydrogenated tallow alkyl)methyl, chlorides. 721.10479 Section 721.10479...hydrogenated tallow alkyl)methyl, chlorides. (a) Chemical substance and significant...hydrogenated tallow alkyl)methyl, chlorides (PMN P-04-335; CAS No....

  15. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting . (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  16. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting . (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  17. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting . (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  18. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting. (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  19. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Uses for Specific Chemical Substances § 721...alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant...reporting . (1) The chemical substance identified...alkyldimethyl, chlorides, reaction products...

  20. 40 CFR 721.10479 - Quaternary ammonium compounds, tris(hydrogenated tallow alkyl)methyl, chlorides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...(hydrogenated tallow alkyl)methyl, chlorides. 721.10479 Section 721.10479 Protection of Environment..., tris(hydrogenated tallow alkyl)methyl, chlorides. (a) Chemical substance and significant new uses...(hydrogenated tallow alkyl)methyl, chlorides (PMN P-04-335; CAS No. 308074-73-9) is subject to reporting...

  1. Characterization of Micelles of Quaternary Ammonium Surfactants as Reaction Media I: Dodeclytrimethylammonium Bromide and Chloride

    E-print Network

    Bales, Barney

    : Dodeclytrimethylammonium Bromide and Chloride Barney L. Bales*, and Raoul Zana Department of Physics and Astronomy resonance (EPR) were employed to characterize micelles of dodecyltrimethylammonium bromide and chloride of pyrene by hexadecyl- pyridinium chloride, kq, were measured with TRFQ. Both these aggregation numbers

  2. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... alkyldimethyl, chlorides, reaction products with silica. 721.10154 Section 721.10154 Protection of Environment..., dicoco alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant..., dicoco alkyldimethyl, chlorides, reaction products with silica (PMN P-08-157; CAS No. 956147-76-5)...

  3. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alkyldimethyl, chlorides, reaction products with silica. 721.10154 Section 721.10154 Protection of Environment..., dicoco alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant..., dicoco alkyldimethyl, chlorides, reaction products with silica (PMN P-08-157; CAS No. 956147-76-5)...

  4. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alkyldimethyl, chlorides, reaction products with silica. 721.10154 Section 721.10154 Protection of Environment..., dicoco alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant..., dicoco alkyldimethyl, chlorides, reaction products with silica (PMN P-08-157; CAS No. 956147-76-5)...

  5. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkyldimethyl, chlorides, reaction products with silica. 721.10154 Section 721.10154 Protection of Environment..., dicoco alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant..., dicoco alkyldimethyl, chlorides, reaction products with silica (PMN P-08-157; CAS No. 956147-76-5)...

  6. 40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alkyldimethyl, chlorides, reaction products with silica. 721.10154 Section 721.10154 Protection of Environment..., dicoco alkyldimethyl, chlorides, reaction products with silica. (a) Chemical substance and significant..., dicoco alkyldimethyl, chlorides, reaction products with silica (PMN P-08-157; CAS No. 956147-76-5)...

  7. 40 CFR 721.10479 - Quaternary ammonium compounds, tris(hydrogenated tallow alkyl)methyl, chlorides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...(hydrogenated tallow alkyl)methyl, chlorides. 721.10479 Section 721.10479 Protection of Environment..., tris(hydrogenated tallow alkyl)methyl, chlorides. (a) Chemical substance and significant new uses...(hydrogenated tallow alkyl)methyl, chlorides (PMN P-04-335; CAS No. 308074-73-9) is subject to reporting...

  8. Synthesis and thermotropic properties of novel double-chained quaternary ammonium chlorides with symmetric and asymmetric hydrocarbon chain length

    NASA Astrophysics Data System (ADS)

    Ding, Zhaoyun; Hao, Aiyou

    2009-04-01

    A series of novel double-chained quaternary ammonium chlorides with symmetrical and asymmetrical hydrocarbon chain length R 1-O-CH 2-CH(OH)-CH 2-N +(CH 3) 2-R 2·Cl - (R 1, R 2: C 12H 25, C 14H 29, C 16H 33) have been synthesized by the reaction of 1- O-alkyl glycidyl ether with N, N-dimethylalkylamine and N, N-dimethylalkylamine hydrochloride. Their chemical structures have been characterized through FT-IR, 1H NMR, MS and elementary analysis. Their thermotropic properties have been examined by differential scanning calorimetry (DSC), polarizing light microscopy (PLM) and X-ray diffraction (XRD). It has been found that the compounds with longer hydrocarbon chain length and being higher asymmetry in hydrocarbon chain length exhibit lower melting point ( Tm) , isotropization temperature ( Ti) and narrower mesophase temperature range. However, the hydrocarbon chain length and the symmetry in the hydrocarbon chain length have little influence on the type of liquid crystals. All compounds form cholesteric liquid crystal.

  9. 40 CFR 721.10511 - Quaternary ammonium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Quaternary ammonium salts (generic). 721.10511 Section 721...Substances § 721.10511 Quaternary ammonium salts (generic). (a) Chemical substance...identified generically as quaternary ammonium salts (PMNs P-07-320,...

  10. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Ethoxylated alkyl quaternary ammonium compound. 721.655 Section 721.655 ...Ethoxylated alkyl quaternary ammonium compound. (a) Chemical substance and significant...ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject...

  11. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium chloride. 184.1138 Section 184.1138 Food... Specific Substances Affirmed as GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution....

  12. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium chloride. 184.1138 Section 184.1138 Food... Specific Substances Affirmed as GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution....

  13. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium chloride. 184.1138 Section 184.1138 Food... Specific Substances Affirmed as GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution....

  14. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium chloride. 184.1138 Section 184.1138 Food... Specific Substances Affirmed as GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution....

  15. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium chloride. 184.1138 Section 184.1138 Food... GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium...

  16. Synthesis and Antibacterial Activity of Novel Quaternary Ammonium Pyridoxine Derivatives.

    PubMed

    Shtyrlin, Nikita V; Sapozhnikov, Sergey V; Koshkin, Sergey A; Iksanova, Alfiya G; Sabirov, Arthur H; Kayumov, Airat R; Nureeva, Aliya A; Zeldi, Marina I; Shtyrlin, Yurii G

    2015-01-01

    A series of 26 quaternary ammonium pyridoxine derivatives were synthesized and their cytotoxicity and antibacterial activities against clinically relevant bacterial strains were tested in vitro. The antibacterial activity of mono-ammonium salts increased with the rise of the lipophilicity and compound 3,3,5-trimethyl-8,8-dioctyl-1,7,8,9-tetrahydro-[1,3]dioxino[5,4-d]pyrrolo[3,4-b]pyridin-8- ium chloride (2d) reaches a maximum among them. Bis-ammonium salt of pyridoxine 4 with two dimethyloctylamine groups also demonstrated high antibacterial activity despite lower lipophilicity. The results of MTT assay indicated that HEK 293 cells were more sensitive than HSF to quaternary ammonium pyridoxine derivatives. Compounds 2d and 4 did not induce the damage of the DNA and might be of interest in the development of new antimicrobials. PMID:25938426

  17. Radiolysis of simple quaternary ammonium salt components of Amberlite resin

    NASA Astrophysics Data System (ADS)

    Dhiman, Surajdevprakash B.; LaVerne, Jay A.

    2013-05-01

    The radiation chemical yields of gaseous products, H2 and CH4, in the radiolysis of dry methylammonium chloride, dimethylammonium chloride, trimethylammonium chloride, tetramethylammonium chloride and benzyl trimethylammonium chloride by ?-rays and 5 MeV helium ions have been investigated. Some of these amines are the different components of the quaternary ammonium resin Amberlite, which is a strongly basic anion exchange resin based on a polystyrene divinylbenzene copolymer. Molecular hydrogen yields with ?-radiolysis range from a high of 4.43 molecules per 100 eV for trimethylammonium chloride to 0.07 and 0.05 molecules per 100 eV for tetramethylammonium chloride and benzyl trimethylammonium chloride, respectively. Yields of methane gas are generally negligible except for trimethylammonium chloride and tetramethylammonium chloride, 0.26 and 0.02 molecules per 100 eV, respectively. Isotopic labeling studies suggest that the first step in H2 production is the breakage of the Nsbnd H bond followed by abstraction of Hrad atom from the methyl groups. EPR analysis shows the formation of both N and C centered radicals. A comparison is made between the radiolysis of Amberlite and its various components.

  18. Tri­benzyl­ammonium chloride

    PubMed Central

    Diallo, Waly; Diop, Libasse; Plasseraud, Laurent; Cattey, Hélène

    2014-01-01

    Single crystals of the title salt, C21H21NH+·Cl?, were isolated as a side product from the reaction involving [(C6H5CH2)3NH]2[HPO4] and Sn(CH3)3Cl in ethanol. Both the cation and the anion are situated on a threefold rotation axis. The central N atom in the cation has a slightly distorted tetra­hedral environment, with angles ranging from 107.7 to 111.16?(10)°. In the crystal, the tri­benzyl­ammonium cations and chloride anions are linked through N—H?Cl and C—H?Cl hydrogen bonds, leading to the formation of infinite chains along [001]. The crystal studied was a merohedral twin. PMID:24860409

  19. Tri-benzyl-ammonium chloride.

    PubMed

    Diallo, Waly; Diop, Libasse; Plasseraud, Laurent; Cattey, Hélène

    2014-05-01

    Single crystals of the title salt, C21H21NH(+)·Cl(-), were isolated as a side product from the reaction involving [(C6H5CH2)3NH]2[HPO4] and Sn(CH3)3Cl in ethanol. Both the cation and the anion are situated on a threefold rotation axis. The central N atom in the cation has a slightly distorted tetra-hedral environment, with angles ranging from 107.7 to 111.16?(10)°. In the crystal, the tri-benzyl-ammonium cations and chloride anions are linked through N-H?Cl and C-H?Cl hydrogen bonds, leading to the formation of infinite chains along [001]. The crystal studied was a merohedral twin. PMID:24860409

  20. 40 CFR 721.10511 - Quaternary ammonium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Quaternary ammonium salts (generic... Specific Chemical Substances § 721.10511 Quaternary ammonium salts (generic). (a) Chemical substance and... ammonium salts (PMNs P-07-320, P-07-321, P-07-322, P-07-323, and P-07-324) are subject to reporting...

  1. 40 CFR 721.10511 - Quaternary ammonium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Quaternary ammonium salts (generic... Specific Chemical Substances § 721.10511 Quaternary ammonium salts (generic). (a) Chemical substance and... ammonium salts (PMNs P-07-320, P-07-321, P-07-322, P-07-323, and P-07-324) are subject to reporting...

  2. Occupational dermatitis to 2,3-epoxypropyl trimethyl ammonium chloride.

    PubMed

    Estlander, T; Jolanki, R; Kanerva, L

    1986-01-01

    4 workers developed hand dermatitis in an automated starch modification process plant. 2,3-epoxypropyl trimethyl ammonium chloride (EPTMAC), a quaternary ammonium compound used as a cationizing chemical, produced allergic reactions in all 4 patients. They had only been in contact with EPTMAC for a short time before developing dermatitis, which indicates that EPTMAC is a strong sensitizer. Immunohistochemistry and electron microscopy showed the features of an allergic patch test. An industrial hygiene project was initiated at the factory to prevent new cases. It revealed many risks of skin contact with the process chemicals. Thus an automated process does not guarantee protection. PMID:2936558

  3. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Quaternary ammonium salt of fluorinated alkylaryl amide. 721...Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl amide. ...identified generically as quaternary ammonium salt of fluorinated alkylaryl amide...

  4. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Quaternary ammonium salt of fluorinated alkylaryl amide. 721...Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl amide. ...identified generically as quaternary ammonium salt of fluorinated alkylaryl amide...

  5. Surface Micellization Patterns of Quaternary Ammonium Surfactants on Mica

    E-print Network

    Aksay, Ilhan A.

    Surface Micellization Patterns of Quaternary Ammonium Surfactants on Mica Heather N. Patrick equilibrium structures of adsorbed films of quaternary ammonium surfactants on mica have been investigated never been reported on graphite. Mica is a model hydrophilic surface and has been previously used

  6. Antimicrobial Polymeric Materials with Quaternary Ammonium and Phosphonium Salts

    PubMed Central

    Xue, Yan; Xiao, Huining; Zhang, Yi

    2015-01-01

    Polymeric materials containing quaternary ammonium and/or phosphonium salts have been extensively studied and applied to a variety of antimicrobial-relevant areas. With various architectures, polymeric quaternary ammonium/phosphonium salts were prepared using different approaches, exhibiting different antimicrobial activities and potential applications. This review focuses on the state of the art of antimicrobial polymers with quaternary ammonium/phosphonium salts. In particular, it discusses the structure and synthesis method, mechanisms of antimicrobial action, and the comparison of antimicrobial performance between these two kinds of polymers. PMID:25667977

  7. Quaternary Ammonium Biocides: Efficacy in Application

    PubMed Central

    2014-01-01

    Quaternary ammonium compounds (QACs) are among the most commonly used disinfectants. There has been concern that their widespread use will lead to the development of resistant organisms, and it has been suggested that limits should be place on their use. While increases in tolerance to QACs have been observed, there is no clear evidence to support the development of resistance to QACs. Since efflux pumps are believe to account for at least some of the increased tolerance found in bacteria, there has been concern that this will enhance the resistance of bacteria to certain antibiotics. QACs are membrane-active agents interacting with the cytoplasmic membrane of bacteria and lipids of viruses. The wide variety of chemical structures possible has seen an evolution in their effectiveness and expansion of applications over the last century, including non-lipid-containing viruses (i.e., noroviruses). Selection of formulations and methods of application have been shown to affect the efficacy of QACs. While numerous laboratory studies on the efficacy of QACs are available, relatively few studies have been conducted to assess their efficacy in practice. Better standardized tests for assessing and defining the differences between increases in tolerance versus resistance are needed. The ecological dynamics of microbial communities where QACs are a main line of defense against exposure to pathogens need to be better understood in terms of sublethal doses and antibiotic resistance. PMID:25362069

  8. Cotton gauze bearing non-diffusible quaternary ammonium salts and featuring anti-microbial activity: An example of single-use articles tailored to self-sterilize

    E-print Network

    Taralp, Alpay

    salts was afforded by penetrating 3-trimethoxysilylpropyloctadecylammonium chloride, commonly known, and quaternization using iodomethane. Iodine-based colorimetric methods indicated that quaternary ammonium groups resided on the cotton whereas spectroscopic IR measurements clearly under detection thresholds implied

  9. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  10. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  11. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  12. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  13. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  14. Antimicrobial cotton containing N-halamine and quaternary ammonium groups by grafting copolymerization

    NASA Astrophysics Data System (ADS)

    Liu, Ying; Liu, Yin; Ren, Xuehong; Huang, T. S.

    2014-03-01

    The monomer (3-acrylamidopropyl)trimethylammonium chloride (APTMAC) was used to treat cotton fibers by grafting copolymerization. The grafted cotton fabrics were characterized by SEM image and FTIR spectra. The treated samples with quaternary ammonium groups could decrease 96.08% of Staphylococcus aureus and 48.74% of Escherichia coli O157:H7 within 30 min. After chlorination with dilute sodium hypochlorite, the treated cotton fabrics containing both N-halamine and quaternary ammonium groups effectively inactivated 100% (log reduction 5.82) of S. aureus and 100% (log reduction 6.26) of E. coli O157:H7 within 5 min of contact time. The grafting process of cotton fabric has small effect on the thermal stability and tensile strength, which favors the practical application. Compared to the traditional pad-dry-cure method to produce antibacterial materials, the radical grafting copolymerization method occurred in water without any organic solvents involved in the whole treatment.

  15. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  16. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  17. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. ...ethanedisulfonate and 80 milligrams of ammonium chloride.1 1 These conditions are...

  18. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. ...ethanedisulfonate and 80 milligrams of ammonium chloride.1 1 These conditions are...

  19. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Applicability; description of the ammonium chloride production subcategory. 415.240...MANUFACTURING POINT SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The...

  20. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Applicability; description of the ammonium chloride production subcategory. 415.240...MANUFACTURING POINT SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The...

  1. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. ...ethanedisulfonate and 80 milligrams of ammonium chloride.1 1 These conditions are...

  2. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. ...ethanedisulfonate and 80 milligrams of ammonium chloride.1 1 These conditions are...

  3. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Applicability; description of the ammonium chloride production subcategory. 415.240...MANUFACTURING POINT SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The...

  4. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section 520...Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. ...ethanedisulfonate and 80 milligrams of ammonium chloride.1 1 These conditions are...

  5. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Applicability; description of the ammonium chloride production subcategory. 415.240...MANUFACTURING POINT SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The...

  6. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Applicability; description of the ammonium chloride production subcategory. 415.240...MANUFACTURING POINT SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The...

  7. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  8. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  9. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  10. Quaternary ammonium polyethylenimine nanoparticles for treating bacterial contaminated water.

    PubMed

    Farah, Shady; Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Beyth, Nurit; Domb, Abraham J

    2015-04-01

    This study highlights the potential application of antimicrobial quaternary ammonium nanomaterials for water disinfection. Quaternary ammonium polyethylenimine (QA-PEI) nanoparticles (NPs) were synthesized by polyethylenimine crosslinking and alkylation with octyl iodide followed by methyl iodide quaternization. Particles modified with octyldodecyl alkyl chains were also prepared and evaluated. The antimicrobial activity of QA-PEI NPs was studied after anchoring in non-leaching polymeric coatings and also in aqueous suspension. Particles at different loadings (w/w) were embedded in polyethylene vinyl acetate and polyethylene methacrylic acid coatings and tested for antimicrobial activity against four representative strains of bacteria in static and dynamic modes. Coatings embedded with fluorescent labelled particles tracked by Axioscope fluorescence microscope during the antimicrobial test indicates no particles leaching out. Coatings loaded with 5% w/w QA-PEI exhibited strong antibacterial activity. Aqueous suspension was tested and found effective for bacterial decontamination at 0.1 ppm and maintains its activity for several weeks. PMID:25800358

  11. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Modified polymer of vinyl acetate and quaternary ammonium...Chemical Substances § 721.8658 Modified polymer of vinyl acetate and quaternary ammonium...substance identified generically as modified polymer of vinyl acetate and quaternary...

  12. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Modified polymer of vinyl acetate and quaternary ammonium...Chemical Substances § 721.8658 Modified polymer of vinyl acetate and quaternary ammonium...substance identified generically as modified polymer of vinyl acetate and quaternary...

  13. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Modified polymer of vinyl acetate and quaternary ammonium...Chemical Substances § 721.8658 Modified polymer of vinyl acetate and quaternary ammonium...substance identified generically as modified polymer of vinyl acetate and quaternary...

  14. The Use of Quaternary Ammonium to Combat Dental Caries

    PubMed Central

    Ge, Yang; Wang, Suping; Zhou, Xuedong; Wang, Haohao; Xu, Hockin H. K.; Cheng, Lei

    2015-01-01

    Resin composites and adhesives are increasingly popular in dental restorations, but secondary caries is one of the main reasons for restoration failure. Quaternary ammonium monomers (QAMs) have an anti-microbial effect and are widely used in many fields. Since the concept of the immobilized antibacterial effect was put forward, dental restorations containing QAMs have been studied to reduce secondary caries. Previous studies have been struggling to develop novel anti-caries materials which might have triple benefits: good mechanical properties, antibacterial effects and remineralization potentials. Different kinds of QAMs have been proven to be effective in inhibiting the growth and metabolism of biofilms. Combination of QAMs and other nanoparticles in resin composites and adhesives could enhance their anti-caries capability. Therefore, QAMs are promising to show significant impact on the future of restorative and preventive dentistry. PMID:26635932

  15. Effects of quaternary ammonium-methacrylates on the mechanical properties of unfilled resins

    PubMed Central

    Hoshika, Tomohiro; Nishitani, Yoshihiro; Yoshiyama, Masahiro; Key, William O.; William, Brantley; Agee, Kelli A.; Breschi, Lorenzo; Cadenaro, Milena; Tay, Franklin R.; Rueggeberg, Frederick; Pashley, David H.

    2014-01-01

    Objectives Adding antimicrobial/anti-MMP quaternary ammonium methacrylates (QAMs) to comonomer blends should not weaken the mechanical properties of dental resins. This work evaluated the degree conversion and mechanical properties of BisGMA/TEGDMA/HEMA (60:30:10) containing 0–15 mass% QAMs A–E (A:2-acryloxyethyltrimethyl ammonium chloride; B:[3-(methacryloylamino)propyl]trimethylammonium chloride; C:[2-(methacryloxy)ethyl] trimethyl ammonium chloride; D:diallyldimethyl ammonium chloride; E:2-(methacryloyloxy) ethyltrimethyl ammonium methyl sulfate. Methods Unfilled resins with and without QAM were placed on ATR-FTIR and light-polymerized for 20 s in a thin film t 30°C. Unfilled resin beams were casted from square hollow glass tubings. Half of the beams were tested after 3 days of drying (control); the other half were tested wet after 3 days of water storage. Results Addition of QAMs in control resins significantly increased conversion 600s after light termination, with the exception of 5% MAPTAC (p<0.05). Increase of QAM content within a formulation significantly increased conversion. Control beams gave dry Young’s moduli of ~700 MPa. Addition of 5, 10 or 15 mass% QAMs produced significant reductions in dry Young’s moduli except for 5% B or C. 15 mass% A, B and C lowered the wet Young’s moduli of the resin beams by more than 30%. The ultimate tensile stress (UTS) of control dry resin was 89±11 MPa. Addition of 5–10 mass% QAMs had no adverse effect on the dry UTS. After water storage, the UTS of all resin blends fell significantly (p<0.05), especially when 15 wt% QAMs was added. Control dry beams gave fracture toughness (KIC) values of 0.88±0.1 MPa?m. Wet values were significantly higher at 1.02±0.06 (p<0.05). KIC of dry beams varied from 0.85±0.08 at 5% QAMs to 0.49±0.05 at 15% QAMs. Wet beams gave KIC values of 1.02±0.06 MPa?m that fell to 0.23±0.01 at 15% QAMs. Significance Addition of 10% QAMs increased the degree of conversion of unfilled resins, but lowered wet toughness and UTS; addition of 15% QAMs lowered the mechanical properties of wet resins below acceptable levels. PMID:25199439

  16. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. 878.4015...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification...With Poly (Diallyl Dimethyl Ammonium Chloride) (pDADMAC) Additive.” See §...

  17. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. 878.4015...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification...With Poly (Diallyl Dimethyl Ammonium Chloride) (pDADMAC) Additive.” See §...

  18. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. 878.4015...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification...With Poly (Diallyl Dimethyl Ammonium Chloride) (pDADMAC) Additive.” See §...

  19. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. 878.4015...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification...With Poly (Diallyl Dimethyl Ammonium Chloride) (pDADMAC) Additive.” See §...

  20. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. 878.4015...with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification...With Poly (Diallyl Dimethyl Ammonium Chloride) (pDADMAC) Additive.” See §...

  1. Kinetics of synthesizing polymer-supported quaternary ammonium catalysts.

    PubMed

    Wu, Ho-Shing; Lo, Chi-Wei

    2006-01-01

    This study attempted to synthesize the optimum quaterary ammonium poly(styrene-co-methylstyrene) catalyst using the combinatorial chemistry method. The catalyst was synthesized by a mix-split method. A phase-transfer catalyst library with 25 kinds of polystyrene-supported quaternary ammonium salt catalyst was the the result of the reaction of five kinds of chloromethylated crosslinked polystyrene with five tert-amines. The allylation of phenol and the oxidation of benzyl alcohol were used as the probing reaction to screen out the most active catalyst for the reaction using the iterative deconvolution method. The screening conditions included teritary amine and organic solvent. The structure of the most active catalyst in the allylation of phenol shows 20 mol % ring substitution and 0.177-0.25-mm pellet size activated with trihexylamine. For oxidation of benzyl alcohol, the reaction conditions of the most active catalyst included a resin of 20% ring substitution and pellet size of 0.177-0.25 mm, activated with triethylamine reacting in an organic solvent of n-hexane. PMID:17096574

  2. Synergistic effect of heartwood extractives and quaternary ammonium compounds on termite resistance of treated wood.

    PubMed

    Hwang, Won-Joung; Kartal, S Nami; Yoshimura, Tsuyoshi; Imamura, Yuji

    2007-01-01

    This study evaluates the synergistic effect of wood extractives and quaternary ammonium compounds (QACs) on the resistance to termites of several treated wood species. Wood specimens from different natural durability classes were extracted with either hot water alone or hot water + ethanol/benzene. The extracted and unextracted wood specimens were treated with either didecyldimethylammonium tetrafluoroborate (DBF) or commercial didecyldimethylammonium chloride (DDAC) solutions and then exposed to subterranean termites, Coptotermes formosanus Shiraki, for 3 weeks under laboratory conditions. The results showed that extractives of the heartwood portions of the wood species contributed to increased resistance against termite attack in the presence of either DBF or DDAC wood preservatives. The synergistic effect of wood extractives and DBF was much clearer with Pseudotsuga menziesii (Mirbel) Franco and Tsuga heterophylla Sarg wood samples. Further studies are needed for a better understanding of the synergism between wood extractives and either DBF or DDAC using both the sapwood and heartwood portions of the same wood species. PMID:17054087

  3. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  4. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  5. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  6. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  7. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  8. Induction of contact drematitis in guinea pigs by quaternary ammonium compounds: the mechanisms of antigen formation

    SciTech Connect

    Schallreuter, K.R.; Schulz, K.H.; Wood, J.M.

    1986-12-01

    Eight quaternary ammonium compounds were tested for their ability to induce contact dermatitis in guinea pigs by using a modified Freund's complete adjuvant test together with the guinea pig maximization test. Only two quaternary ammonium salts of eight tested could be designated as strong allergens. These two active substances were shown to be capable of stable association with membrane lipids in forming immunogenic complexes. This surface complexation phenomenon was confirmed by using a spin-labeled quaternary ammonium salt which competed for binding sites to the surface of epidermal cells in vivo. Electron spin resonance was used to demonstrate that stable ion-pairs are formed between binding sites and the two allergenic preservatives. Furthermore, information was obtained on the kinetics of immunogenic complex formation as well as on the position and orientation of the quaternary ammonium ion at the cell surface.

  9. Tetracalcium phosphate composite containing quaternary ammonium dimethacrylate with antibacterial properties

    PubMed Central

    Cheng, Lei; Weir, Michael D.; Limkangwalmongkol, Penwadee; Hack, Gary D.; Xu, Hockin H. K.; Chen, Qianming; Zhou, Xuedong

    2012-01-01

    Tooth caries is a carbohydrate-modified bacterial infectious disease, and recurrent caries is a frequent reason for restoration failure. The objective of this study was to develop a novel antibacterial composite using tetracalcium phosphate (TTCP) fillers and bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, which is a quaternary ammonium dimethacrylate (QADM). QADM was synthesized using 2-(N,N-dimethylamino)ethyl methacrylate and 2-bromoethyl methacrylate and incorporated into a resin. The resin was filled with 40% TTCP and 30% glass particles. The following QADM mass fractions in the composite were tested: 0%, 6%, 12%, and 18%. Streptococcus mutans biofilms were formed on the composites and the colony-forming units (CFUs), metabolic activity, and lactic acid production were measured. The TTCP-QADM composite had flexural strength and elastic modulus similar to those of two commercial composites (p > 0.1). Increasing the QADM content in TTCP composite greatly decreased the bacteria growth and biofilm matrix production. There were significantly more dead bacteria with increasing QADM content. TTCP composite containing 18% QADM had biofilm CFU, metabolic activity, and acid production about half of those without QADM. Inversely linear relationships were established between QADM mass fraction and S. mutans biofilm CFU, metabolic activity, and acid production, with correlation coefficients R2 ? 0.98. In conclusion, TTCP-QADM composites were developed and the effect of QADM mass fraction on the antibacterial properties of the composite was determined for the first time. The novel TTCP-QADM composites possessing a strong antibacterial capability, together with calcium phosphate ion release and good mechanical properties, are promising for dental restorations to reduce biofilm growth and recurrent caries. PMID:22190356

  10. Effects of Quaternary Ammonium Chain Length on Antibacterial Bonding Agents

    PubMed Central

    Li, F.; Weir, M.D.; Xu, H.H.K.

    2013-01-01

    The objectives of this study were to synthesize new quaternary ammonium methacrylates (QAMs) with systematically varied alkyl chain lengths (CL) and to investigate, for the first time, the CL effects on antibacterial efficacy, cytotoxicity, and dentin bond strength of bonding agents. QAMs were synthesized with CL of 3 to 18 and incorporated into Scotchbond Multi-Purpose (SBMP) bonding agent. The cured resins were inoculated with Streptococcus mutans. Bacterial early attachment was investigated at 4 hrs. Biofilm colony-forming units (CFU) were measured after 2 days. With CL increasing from 3 to 16, the minimum inhibitory concentration and minimum bactericidal concentration were decreased by 5 orders of magnitude. Incorporating QAMs into SBMP reduced bacterial early attachment, with the least colonization at CL = 16. Biofilm CFU for CL = 16 was 4 log lower than SBMP control (p < .05). All groups had similar dentin bond strengths (p > .1). The new antibacterial materials had fibroblast/odontoblast viability similar to that of commercial controls. In conclusion, increasing the chain length of new QAMs in bonding agents greatly increased the antibacterial efficacy. A reduction in Streptococcus mutans biofilm CFU by 4 log could be achieved, without compromising bond strength and cytotoxicity. New QAM-containing bonding agents are promising for a wide range of restorations to inhibit biofilms. PMID:23958761

  11. Cellular uptake of polyurethane nanocarriers mediated by gemini quaternary ammonium.

    PubMed

    Ding, Mingming; He, Xueling; Wang, Zhigao; Li, Jiehua; Tan, Hong; Deng, Hua; Fu, Qiang; Gu, Qun

    2011-12-01

    The effective passage of drug formulations into tumor cells is a key factor in the development of nanoscale delivery systems. However, rapid cellular uptake with reduced toxicity remains a great challenge for efficient and safe delivery. In this study, we first use gemini quaternary ammonium (GQA) as a cell internalization promoter to enhance the cellular uptake of drug nanocarriers. It is found that a twenty times faster cell internalization could be achieved by introducing GQA into biodegradable multiblock polyurethane nanomicelles, as confirmed by flow cytometry and confocal laser scanning microscopy (CLSM) studies. Meanwhile, an added methoxyl-poly(ethylene glycol) (mPEG) outer corona could protect these cationic micelles from cytotoxicity at high concentrations, as verified by methyl tetrazolium (MTT) assay. Moreover, GQA not only acts as an enhancer for rapid cellular entry, but also plays an important role in controlled self-assembly and high drug loading capacity. Our work offers a new understanding on the role of cationic surfactants; and provides a facile and economical approach for the design of versatile drug nanocarriers to achieve efficient delivery and good biocompatibility. PMID:21907404

  12. Interaction of ochratoxin A with quaternary ammonium beta-cyclodextrin.

    PubMed

    Poór, Miklós; Kunsági-Máté, Sándor; Szente, Lajos; Matisz, Gergely; Secenji, Györgyi; Czibulya, Zsuzsanna; K?szegi, Tamás

    2015-04-01

    Ochratoxin A (OTA) is a widely spread nephrotoxic food contaminant mycotoxin. Unfortunately, attenuation or prevention of the toxic effects of OTA is still an unresolved problem. Molecular inclusion of OTA by cyclodextrins (CDs) results in complexes with low stability. In the human organism, OTA exists mostly in the dianionic state (OTA(2-)). Therefore, our major goal was to develop a chemically modified cyclodextrin which gives a more stable complex with OTA than the previously published derivatives and which shows stronger preference towards OTA(2-). In our fluorescence spectroscopic study we demonstrate that quaternary ammonium beta-cyclodextrin (QABCD) fulfils both of these requirements. The calculated stability constant of the QABCD-OTA(2-) complex was 28,840 M(-1) (about 200-fold higher than that of the ?-CD-OTA(2-) complex). We hypothesize, that QABCD may be a suitable tool for the decontamination of different OTA-contaminated drinks; furthermore, for alleviation of the toxic effects of OTA, such complex formation may reduce its absorption from the intestine. PMID:25442535

  13. Inhibition of biofouling by modification of forward osmosis membrane using quaternary ammonium cation.

    PubMed

    Park, Kang-Hee; Yu, Sang-Hyun; Kim, Han-Shin; Park, Hee-Deung

    2015-01-01

    In the operation of the forward osmosis (FO) process, biofouling of the membrane is a potentially serious problem. Development of an FO membrane with antibacterial properties could contribute to a reduction in biofouling. In this study, quaternary ammonium cation (QAC), a widely used biocidal material, was conjugated with a silane coupling agent (3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride) and used to modify an FO membrane to confer antibacterial properties. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the conjugated QAC was successfully immobilized on the FO membrane via covalent bonding. Bacterial viability on the QAC-modified membrane was confirmed via colony count method and visualized via bacterial viability assay. The QAC membrane decreased the viability of Escherichia coli to 62% and Staphylococcus aureus to 77% versus the control membrane. Inhibition of biofilm formation on the QAC modified membrane was confirmed via anti-biofilm tests using the drip-flow reactor and FO unit, resulting in 64% and 68% inhibition in the QAC-modified membrane against the control membrane, respectively. The results demonstrate the effectiveness of the modified membrane in reducing bacterial viability and inhibiting biofilm formation, indicating the potential of QAC-modified membranes to decrease operation costs incurred by biofouling. PMID:26287832

  14. Dynamic Covalent Chemistry of Nucleophilic Substitution Component Exchange of Quaternary Ammonium Salts.

    PubMed

    Kulchat, Sirinan; Lehn, Jean-Marie

    2015-11-01

    Dynamic covalent libraries (DCLs) of quaternary ammonium cations were set up by reversible nucleophilic substitution (SN 2' and SN 2) exchange reactions of ammonium salts and tertiary amines. The reactions were conducted at 60?°C to generate thermodynamically and kinetically controlled mixtures of quaternary ammonium compounds and tertiary amines, and were accelerated by using iodide as a nucleophilic catalyst. Microwave irradiation was used to assist the exchange reaction between the pyridinium salts and pyridine derivatives. Finally, experiments towards the generation of dynamic ionic liquids were performed. The results of this study pave the way for the extension of dynamic combinatorial chemistry to nucleophilic substitution reactions. PMID:26213320

  15. Copper and Quaternary Ammonium Cations Exert Synergistic Bactericidal and Antibiofilm Activity against Pseudomonas aeruginosa?

    PubMed Central

    Harrison, Joe J.; Turner, Raymond J.; Joo, Daniel A.; Stan, Michelle A.; Chan, Catherine S.; Allan, Nick D.; Vrionis, Helen A.; Olson, Merle E.; Ceri, Howard

    2008-01-01

    Biofilms are slimy aggregates of microbes that are likely responsible for many chronic infections as well as for contamination of clinical and industrial environments. Pseudomonas aeruginosa is a prevalent hospital pathogen that is well known for its ability to form biofilms that are recalcitrant to many different antimicrobial treatments. We have devised a high-throughput method for testing combinations of antimicrobials for synergistic activity against biofilms, including those formed by P. aeruginosa. This approach was used to look for changes in biofilm susceptibility to various biocides when these agents were combined with metal ions. This process identified that Cu2+ works synergistically with quaternary ammonium compounds (QACs; specifically benzalkonium chloride, cetalkonium chloride, cetylpyridinium chloride, myristalkonium chloride, and Polycide) to kill P. aeruginosa biofilms. In some cases, adding Cu2+ to QACs resulted in a 128-fold decrease in the biofilm minimum bactericidal concentration compared to that for single-agent treatments. In combination, these agents retained broad-spectrum antimicrobial activity that also eradicated biofilms of Escherichia coli, Staphylococcus aureus, Salmonella enterica serovar Cholerasuis, and Pseudomonas fluorescens. To investigate the mechanism of action, isothermal titration calorimetry was used to show that Cu2+ and QACs do not interact in aqueous solutions, suggesting that each agent exerts microbiological toxicity through independent biochemical routes. Additionally, Cu2+ and QACs, both alone and in combination, reduced the activity of nitrate reductases, which are enzymes that are important for normal biofilm growth. Collectively, the results of this study indicate that Cu2+ and QACs are effective combinations of antimicrobials that may be used to kill bacterial biofilms. PMID:18519726

  16. Capillary electrophoresis and liquid chromatography in the analysis of some quaternary ammonium salts used in lozenges as antibacterial agents.

    PubMed

    Taylor, R B; Toasaksiri, S; Reid, R G

    1998-01-01

    A comparison is made of the relative merits of high-performance liquid chromatography and capillary electrophoresis, both using direct UV detection, for the determination of three quaternary ammonium compounds used as the active antibacterial ingredient in lozenge formulations. While both techniques are capable of separating the compounds cetylpyridinium chloride, dequalinium chloride, and benzalkonium chlorides, the liquid chromatographic method involving ion pairing and using a 5-micron cyanopropyl stationary phase, was unable to resolve the benzalkonium chlorides from the lozenge excipients and quantitation was not possible. The capillary electrophoresis method using a 205-mm 50-micron-i.d. capillary with a running buffer of 50% vol/vol 50 mM phosphate buffer at pH 3 provided superior resolution of the three antibacterials in all lozenge formulations. This system was also capable of resolving impurities in the dequalinium chloride both in the standard and in lozenges containing this compound. On the basis of quantitative results previously published, both methods have adequate validation parameters since the relative insensitivity of capillary electrophoresis compared with liquid chromatography is not important at the concentration required to be determined following a single simple sample pretreatment. PMID:10327369

  17. Dual Action Antimicrobials: Nitric Oxide Release from Quaternary Ammonium-Functionalized Silica Nanoparticles

    PubMed Central

    Carpenter, Alexis W.; Worley, Brittany V.; Slomberg, Danielle L.; Schoenfisch, Mark H.

    2012-01-01

    The synthesis of quaternary ammonium (QA)-functionalized silica nanoparticles with and without nitric oxide (NO) release capabilities is described. Glycidyltrialkylammonium chlorides of varied alkyl chain lengths (i.e., methyl, butyl, octyl, and dodecyl) were tethered to the surface of amine-containing silica nanoparticles via a ring-opening reaction. Secondary amines throughout the particle were then functionalized with N-diazeniumdiolates NO donors to yield dual functional nanomaterials with surface QAs and total NO payloads of ca. 0.3 ?mol/mg. The bactericidal activities of singly (i.e., only NO-releasing or only QA-functionalized) and dual (i.e., NO-releasing and QA-functionalized) functional nanoparticles were tested against Grampositive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa. Particles with only NO release capabilities alone were found to be more effective against P. aeruginosa, while particles with only QA-functionalities exhibited greater toxicity toward S. aureus. The minimum bactericidal concentrations (MBC) of QA-functionalized particles decreased with increasing alkyl chain length against both microbes tested. Combining NO release and QA-functionalities on the same particle resulted in an increase in bactericidal efficacy against S. aureus; however, no change in activity against P. aeruginosa was observed compared to NO-releasing particles alone. PMID:22998760

  18. 77 FR 47291 - Residues of Didecyl Dimethyl Ammonium Chloride; Exemption From the Requirement of a Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-08

    ...EPA-HQ-OPP-2011-0139; FRL-9356-6] Residues of Didecyl Dimethyl Ammonium Chloride...from the requirement of a tolerance for residues of Didecyl dimethyl ammonium chloride...establish a maximum permissible level for residues of DDAC in or on broccoli seed....

  19. Synthesis of hierarchical zeolites using an inexpensive mono-quaternary ammonium surfactant as mesoporogen.

    PubMed

    Zhu, Xiaochun; Rohling, Roderigh; Filonenko, Georgy; Mezari, Brahim; Hofmann, Jan P; Asahina, Shunsuke; Hensen, Emiel J M

    2014-12-01

    A simple amphiphilic surfactant containing a mono-quaternary ammonium head group (N-methylpiperidine) is effective in imparting substantial mesoporosity during synthesis of SSZ-13 and ZSM-5 zeolites. Highly mesoporous SSZ-13 prepared in this manner shows greatly improved catalytic performance in the methanol-to-olefins reaction compared to bulk SSZ-13. PMID:25316609

  20. 75 FR 40729 - Residues of Quaternary Ammonium Compounds, N-Alkyl (C12-14

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ...EPA-HQ-OPP-2008-0533; FRL-8833-2] Residues of Quaternary Ammonium Compounds, N-Alkyl...from the requirement of a tolerance for residues of n-alkyl (C 12-14 ) dimethyl...exempt from the requirement of tolerance residues in food resulting from contact...

  1. Hibiscus sabdariffa Affects Ammonium Chloride-Induced Hyperammonemic Rats

    PubMed Central

    Essa, M. Mohamed

    2007-01-01

    Hibiscus sabdariffa (HS) is an edible medicinal plant, indigenous to India, China and Thailand and is used in Ayurveda and traditional medicine. Alcoholic extract of HS leaves (HSEt) was studied for its anti-hyperammonemic and antioxidant effects in brain tissues of ammonium chloride-induced hyperammonemic rats. Oral administration of HSEt (250 mg kg?1 body weight) significantly normalizes the levels of ammonia, urea, uric acid, creatinine and non-protein nitrogen in the blood. HSEt significantly reduced brain levels of lipid peroxidation products such as thiobarbituric acid and reactive substances (TBARS) and hydroperoxides (HP). However, the administered extract significantly increased the levels of antioxidants such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) in brain tissues of hyperammonemic rats. This investigation demonstrates significant anti-hyperammonemic and antioxidant activity of HS. PMID:17965762

  2. Synthesis, antioxidant and cathepsin D inhibition activity of quaternary ammonium chitosan derivatives.

    PubMed

    Li, Wenjuan; Duan, Yunfei; Huang, Jianying; Zheng, Qunxiong

    2016-01-20

    Two (2-hydroxypropyl) trimethyl ammonium and/or imidazole-based quaternary ammonium chitosan derivatives (NHT-chitosan and Im-OHT-chitosan) were synthesized by using nucleophilic substitution reaction. These two synthesized chitosan derivatives were characterized by Fourier transform infrared spectroscopy, NMR spectra, and UV-visible spectra. The applications as antioxidant agents and cathepsin D inhibitors were further investigated. Both of quaternary ammonium chitosan derivatives exhibited good antioxidant activity upon scavenging against hydroxyl radical and hydrogen peroxide as well as the lipid peroxidation inhibition in the linoleic acid emulsion system. They also exhibited good inhibition activity of cathepsin D protease. NHT-chitosan and Im-OHT-chitosan are potential the natural, healthy and safe preservatives in food industry. PMID:26572425

  3. Liquid-liquid phase separation in particles containing organics mixed with ammonium sulfate, ammonium bisulfate, ammonium nitrate or sodium chloride

    NASA Astrophysics Data System (ADS)

    You, Y.; Renbaum-Wolff, L.; Bertram, A. K.

    2013-07-01

    As the relative humidity varies from high to low values in the atmosphere, particles containing organics and inorganic salts may undergo liquid-liquid phase separation. The majority of the laboratory work on this subject has used ammonium sulfate as the inorganic salt. In the following we studied liquid-liquid phase separation in particles containing organics mixed with the following salts: ammonium sulfate, ammonium bisulfate, ammonium nitrate and sodium chloride. In each experiment one organic was mixed with one inorganic salt and the liquid-liquid phase separation relative humidity (SRH) was determined. Since we studied 23 different organics mixed with four different salts, a total of 92 different particle types were investigated. Out of the 92 types, 49 underwent liquid-liquid phase separation. For all the inorganic salts, liquid-liquid phase separation was never observed when the oxygen-to-carbon elemental ratio (O:C) was ? 0.8 and was always observed for O:C<0.5. For 0.5 ? O:C< 0.8, the results depended on the salt type. Out of the 23 organics investigated, the SRH of 20 organics followed the trend: (NH4)2SO4 ? NH4HSO4 ? NaCl ? NH4NO3. This trend is consistent with previous salting-out studies and the Hofmeister series. Based on the range of O:C values found in the atmosphere and the current results, liquid-liquid phase separation is likely a frequent occurrence in both marine and non-marine environments.

  4. Liquid-liquid phase separation in particles containing organics mixed with ammonium sulfate, ammonium bisulfate, ammonium nitrate or sodium chloride

    NASA Astrophysics Data System (ADS)

    You, Y.; Renbaum-Wolff, L.; Bertram, A. K.

    2013-12-01

    As the relative humidity varies from high to low values in the atmosphere, particles containing organic species and inorganic salts may undergo liquid-liquid phase separation. The majority of the laboratory work on this subject has used ammonium sulfate as the inorganic salt. In the following we studied liquid-liquid phase separation in particles containing organics mixed with the following salts: ammonium sulfate, ammonium bisulfate, ammonium nitrate and sodium chloride. In each experiment one organic was mixed with one inorganic salt and the liquid-liquid phase separation relative humidity (SRH) was determined. Since we studied 23 different organics mixed with four different salts, a total of 92 different particle types were investigated. Out of the 92 types, 49 underwent liquid-liquid phase separation. For all the inorganic salts, liquid-liquid phase separation was never observed when the oxygen-to-carbon elemental ratio (O : C) ≥ 0.8 and was always observed for O : C < 0.5. For 0.5 ≤ O : C < 0.8, the results depended on the salt type. Out of the 23 organic species investigated, the SRH of 20 organics followed the trend: (NH4)2SO4 ≥ NH4HSO4 ≥ NaCl ≥ NH4NO3. This trend is consistent with previous salting out studies and the Hofmeister series. Based on the range of O : C values found in the atmosphere and the current results, liquid-liquid phase separation is likely a frequent occurrence in both marine and non-marine environments.

  5. Selective removal and inactivation of bacteria by nanoparticle composites prepared by surface modification of montmorillonite with quaternary ammonium compounds.

    PubMed

    Khalil, Rowaida K S

    2013-10-01

    The purpose of the present study was to prepare new nanocomposites with antibacterial activities by surface modification of montmorillonite using quaternary ammonium compounds that are widely applied as disinfectants and antiseptics in food-processing environments. The intercalation of four quaternary ammonium compounds namely benzalkonium chloride, cetylpyridinium chloride monohydrate, hexadecyltrimethylammonium bromide, tetraethylammonium chloride hydrate into montmorillonite layers was confirmed by X-ray diffraction. The antibacterial influences of the modified clay variants against important foodborne pathogens differed based on modifiers quantities, microbial cell densities, and length of contact. Elution experiments through 0.1 g of the studied montmorillonite variants indicated that Staphylococcus aureus, Pseudomonas aeroginosa, and Listeria monocytogenes were the most sensitive strains. 1 g of hexadecyltrimethylammonium bromide intercalated montmorillonites demonstrated maximum inactivation of L. monocytogenes populations, with 4.5 log c.f.u./ml units of reduction. In adsorption experiments, 0.1 g of tetraethylammonium chloride hydrate montmorillonite variants significantly reduced the growth of Escherichia coli O157:H7, L. monocytogenes, and S. aureus populations by 5.77, 6.33, and 7.38 log units respectively. Growth of wide variety of microorganisms was strongly inhibited to undetectable levels (chloride montmorillonite variants. This investigation highlights that reduction in counts of microbial populations adsorbed to the new nanocomposites was substantially different from that in elution experiments, where interactions of nanocomposites with bacteria were specific and more complex than simple ability to inactivate. Treatment columns packed with modified variants maintained their inactivation capacity to the growth of Salmonella Tennessee and S. aureus populations after 48 h of incubation at room temperature with maximum reductions of 6.3 and 5.0 log units respectively. New nanocomposites presented in this research may have potential applications in industrial scale for the control of foodborne pathogens by their incorporation into high-performance filters in food processing plant environments where selectivity in removal and/or inactivation of species in fluid flow streams is desirable. Nevertheless, extensive in vitro and in vivo studies of these new nanocomposites is essential to outpace the understanding of their potential impacts and consequences on human health and the environment if they will make an appearance in commercialized food packaging and containment food materials in the future. PMID:23709187

  6. AMMONIUM CHLORIDE DECALCIFICATION, AS MODIFIED BY CALCIUM INTAKE: THE RELATION BETWEEN GENERALIZED OSTEOPOROSIS AND OSTITIS FIBROSA

    PubMed Central

    Jaffe, Henry L.; Bodansky, Aaron; Chandler, Joseph P.

    1932-01-01

    1. In all age groups the effects of ammonium chloride administration were found to be strikingly dependent upon the calcium intake. 2. Dogs receiving an adequate calcium diet and ammonium chloride showed less decalcification than those receiving a low calcium diet with or without ammonium chloride. 3. In the younger groups the added effect of ammonium chloride to calcium-low diet brought out more striking changes than a low calcium diet alone. 4. When the decalcification was less severe—in the oldest dogs on the low calcium diet with or without ammonium chloride, and in the younger dogs on an adequate calcium intake with ammonium chloride —generalized thinning of the bones without marrow fibrosis resulted (osteoporosis). 5. When the decalcification was rapid and severe—in the youngest dogs on low calcium diet, particularly with ammonium chloride— generalized decalcification and secondary marrow fibrosis resulted (ostitis fibrosa). 6. Generalized ostitis fibrosa is a rather inclusive term and may be applied to the histologic picture which results when clinical or experimental decalcification is rapid, and therefore leads to extensive marrow fibrosis. 7. The special underlying causes of the decalcification may incidentally contribute features to modify the generalized osteoporosis or ostitis fibrosa as in rickets and in von Recklinghausen's disease. PMID:19870105

  7. Influence of immobilized quaternary ammonium group surface density on antimicrobial efficacy and cytotoxicity.

    PubMed

    Cavallaro, Alex; Mierczynska, Agnieszka; Barton, Mary; Majewski, Peter; Vasilev, Krasimir

    2016-01-01

    Bacterial colonization of medical devices causes infections and is a significant problem in healthcare. The use of antibacterial coatings is considered as a potential solution to this problem and has attracted a great deal of attention. Using concentration density gradients of immobilized quaternary ammonium compounds it was demonstrated that a specific threshold of surface concentration is required to induce significant bacterial death. It was determined that this threshold was 4.18% NR4(+) bonded nitrogen with a surface potential of + 120.4 mV. Furthermore, it is shown for the first time that adhesion of constituents of the culture medium to the quaternary ammonium modified surface eliminated any cytotoxicity towards eukaryotic cells such as primary human fibroblasts. The implications of this type of surface fouling on the antimicrobial efficacy of surface coatings are also discussed. PMID:26691649

  8. Synthesis of Quaternary Ammonium Salts of Tricyclic Cationic Drugs: A One-Pot Synthesis for the Bioorganic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Brunauer, Linda S.; Mogannam, Abid C.; Hwee, Won B.; Chen, James Y.

    2007-01-01

    A one-pot conversion of tricyclic cationic drugs to their quaternary ammonium forms is described for a widely used bioactive drug: chlorpromazine, a phenothiazine-based antipsychotic. After conversion to its free base, the parent drug was methylated using substoichiometric amounts of methyl iodide dissolved in ether; the charged quaternary

  9. Calibration of the On-Line Aerosol Monitor (OLAM) with ammonium chloride and sodium chloride aerosols

    SciTech Connect

    Brockmann, J.E.; Lucero, D.A.; Romero, T.; Pentecost, G.

    1993-12-01

    The On-Line Aerosol Monitor (OLAM) is a light attenuation device designed and built at the Idaho National Engineering Laboratory (INEL) by EG&G Idaho. Its purpose is to provide an on-line indication of aerosol concentration in the PHEBUS-FP tests. It does this by measuring the attenuation of a light beam across a tube through which an aerosol is flowing. The OLAM does not inherently give an absolute response and must be calibrated. A calibration has been performed at Sandia National Laboratories` (SNL) Sandia Aerosol Research Laboratory (SARL) and the results are described here. Ammonium chloride and sodium chloride calibration aerosols are used for the calibration and the data for the sodium chloride aerosol is well described by a model presented in this report. Detectable instrument response is seen over a range of 0.1 cm{sup 3} of particulate material per m{sup 3} of gas to 10 cm{sup 3} of particulate material per m{sup 3} of gas.

  10. 75 FR 40729 - Residues of Quaternary Ammonium Compounds, N-Alkyl (C12-14

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ...) 305-5805. II. Summary of Petitioned-For Exemption In the Federal Register of November 28, 2007 (72 FR... 12-18 ) dimethyl benzyl ammonium chloride. (73 FR 49101) (August 20, 2008). The commenter mistakenly... Regulatory Planning and Review (58 FR 51735, October 4, 1993). Because this final rule has been exempted...

  11. Development of antibacterial quaternary ammonium silane coatings on polyurethane catheters.

    PubMed

    Zanini, Stefano; Polissi, Alessandra; Maccagni, Elisa A; Dell'Orto, Elisa C; Liberatore, Chiara; Riccardi, Claudia

    2015-08-01

    Polyurethene (PU) catheters were coated with 3-(trimethoxysilyl)-propyldimethyloctadecylammonium chloride (QAS) by means of a multistep process which involved a vapor phase plasma-induced graft-polymerization of acrylic acid (AAc). The AAc coating, whose stability in aqueous media was assessed by immersion in Phospate Buffer Saline (PBS), was characterized by means of Attenuated Total Reflectance Fourier Transform Infrared (ATR/FTIR) spectroscopy. Moreover, the COOH surface density was evaluated by a colorimetric assay with Methylene Blue. Carrying a negative charge at neutral pH, AAc coatings were proficient in positively charged molecules (like QAS) adsorption. ATR/FTIR spectroscopy and a colorimetric assay with Bromophenol Blue allowed us to verify the presence and the uniformity of the QAS coating on the PU catheters and the positive effect of the AAc graft-polymerization on the QAS adsorption. Morphological characterization of the QAS-modified catheters was performed by means of Atomic Force Microscopy (AFM). QAS-coated catheters displayed in vitro antimicrobial activity against Gram-negative Escherichia coli bacterial cells. PMID:25890115

  12. Immobilization of quaternary ammonium salts on grafting particle polystyrene/SiO 2 and preliminary study of application performance

    NASA Astrophysics Data System (ADS)

    Gao, Baojiao; Qi, Changsheng; Liu, Qing

    2008-04-01

    Polystyrene (PSt) was grafted on the surface of silica gel particles in the manner of "grafting from" in a solution polymerization system, and grafting particles PSt/SiO 2 was obtained. The chloromethylation reaction of the grafted polystyrene was performed using a novel chloromethylation reagent, 1,4-bis(chloromethyoxy)butane which is un-carcinogenic, and grafting particles CMPS/SiO 2 was gained. Subsequently, grafted CMPS was quaternized (denoted as QPS) using tertiary amine, and finally functional composite-type particles QPS/SiO 2, on which quaternary ammonium groups were immobilized, were prepared. The catalysis activity of the particle QPS/SiO 2 as a triphase catalyst in phase-transfer catalysis systems and its antibacterial activity as a water-insoluble antibacterial material were studied preliminarily. The experimental results show that the particle QPS/SiO 2 exhibits higher catalysis activity as a triphase catalyst for the reaction between benzyl chloride in organic phase and sodium acetate in aqueous phase to form benzyl acetate, and under a mild condition of 60 °C for 7 h of reaction time a conversion of 66% for benzyl chloride can be obtained. The particle QPS/SiO 2 has high antibacterial activity as a water-insoluble antibacterial material against Escherichia coli ( E. coli).

  13. Reversible phase transformation-type layer shape electrolyte based on POM and quaternary ammonium salt

    NASA Astrophysics Data System (ADS)

    Wu, Xuefei; Li, Yunyan; Wu, Qingyin; Ding, Hong; Yan, Wenfu

    2014-02-01

    A novel kind of organic-inorganic layer shape material, polyoxymetalates (POM)-type ionic liquid (IL) with Keggin structure and simple quaternary ammonium salt, (TOAMe)4PW11VO40 (trioctylmethylammonium = TOAMe,…) is synthesized and characterized by IR, UV, X-ray diffraction (XRD), TG-DTA. Its electrochemical property was investigated by cyclic voltammgram. Research results released the vanadium and the POM structure in the compound can process reduction in DMSO, which is unlikely in water solution as a simple hydrated ion because water will protonize substrate.

  14. [Study of local anaesthetics: Part 206* Micellization of selected of quaternary ammonium salt derived from heptacaine].

    PubMed

    Gališinová, Jana; ?ižmárik, Jozef; Salanci, Eva; Gálusová, Andrea; Stopková, Lenka; Andriamainty, Fils

    2015-01-01

    Micellization of selected quaternary ammonium compounds derived from heptacaine have been studied by absorption spectroscopy in the UV/VIS spectral region with the use of a pyrene probe. The compounds studied in the aqueous solution have been marked as H22, H26, H27, H29, H34, H + Al and H + B and the derivative marked as H34 was studied in a 3 mol/l ethanol solution at the temperature of 25 °C. In the homologous series of the studied bromides H22, H26, H27 and H29, cmc was observed to be dependent on the number of carbon atoms nc in the hydrophobic chain: ln (cmc) = -3.131-0.421nC. The Free Gibbs energy necessary for the transfer of a methyl group of the alkyl chain from the water phase to the inner part of the micelle at the temperature of 25 °C is (-0.421 ± 0.034)RT.Key words: heptacaine quaternary ammonium compounds critical micelle concentration pyrene Boltzmann-sigmoidal equation alcohol. PMID:26459129

  15. Polydimethylsiloxane-polymethacrylate block copolymers tethering quaternary ammonium salt groups for antimicrobial coating

    NASA Astrophysics Data System (ADS)

    Qin, Xiaoshuai; Li, Yancai; Zhou, Fang; Ren, Lixia; Zhao, Yunhui; Yuan, Xiaoyan

    2015-02-01

    Block copolymers PDMS-b-PDMAEMA were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization involving N,N-dimethylaminoethyl methacrylate (DMAEMA) by using poly(dimethylsiloxane) (PDMS) macro-chain transfer agent. And, the tertiary amino groups in PDMAEMA were quaternized with n-octyliodide to provide quaternary ammonium salts (QPDMAEMA). The well-defined copolymers generated composition variation and morphology evolvement on film surfaces, which were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, and contact angle measurements. The results indicated that the enrichment of QPDMAEMA brought about lower elemental ratios of Si/N on the film surfaces. The surface morphologies evolved with the variations of QPDMAEMA content, and the variation trend of film roughness was exactly opposite to that of water contact angle hysteresis. With regard to structure-antimicrobial relationships, the copolymer films had more evident antimicrobial activity against Gram-positive, Bacillus subtilis, and the surfaces with heterogeneous morphology and higher N+ content presented better antimicrobial activity. The functionalized copolymers based PDMS and quaternary ammonium salts materials have the potential applications as antimicrobial coatings.

  16. Palladium-Catalyzed Amination of Aryl Chlorides and Bromides with Ammonium Salts

    PubMed Central

    2014-01-01

    We report the palladium-catalyzed coupling of aryl halides with ammonia and gaseous amines as their ammonium salts. The coupling of aryl chlorides and ortho-substituted aryl bromides with ammonium sulfate forms anilines with higher selectivity for the primary arylamine over the diarylamine than couplings with ammonia in dioxane. The resting state for the reactions of aryl chlorides is different from the resting state for the reactions of aryl bromides, and this change in resting states is proposed to account for a difference in selectivities for reactions of the two haloarenes. PMID:25133675

  17. Performance properties and antibacterial activity of crosslinked films of quaternary ammonium modified starch and poly(vinyl alcohol).

    PubMed

    Sekhavat Pour, Zahra; Makvandi, Pooyan; Ghaemy, Mousa

    2015-09-01

    There has been a growing interest in developing antibacterial polymeric materials. In the present work, novel antibacterial cross-linked blend films were prepared based on polyvinyl alcohol (PVA) and quaternary ammonium starch (ST-GTMAC) using citric acid (CA) as plasticizer and glutaraldehyde (GA) as cross-linker. The ST-GTMAC was successfully synthesized from reaction between water-soluble oxidized starch and glycidyltrimethylammonium chloride (GTMAC). The effect of ST-GTMAC, CA and GA contents on the swelling, solubility, mechanical and thermal properties of the films was investigated. It was found that incorporation of ST-GTMAC reduced UV-transmittance and provided antibacterial properties, increasing GA content increased tensile strength and decreased solubility and swelling degree of the films, while CA acted as plasticizer when its concentration was above 10 wt%. The results showed that ST-GTMAC/PVA/CA/GA film has fair antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. These results suggest that the prepared film might be used as potential antibacterial material in medical and packaging applications. PMID:26188297

  18. Effect of cotton pectin content and bioscouring on alkyl-dimethyl-benzyl-ammonium chloride adsorption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our previous research has shown both the rate and the total amount of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC) exhausted from a bulk solution of ADBAC are significantly greater for greige cotton nonwovens than cotton nonwovens that have been both scoured and bleached. The presence of pectin ...

  19. Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on differently pretreated nonwoven cotton substrate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations and liquor ratios using UV-vis absorption spec...

  20. High levan production by Bacillus licheniformis NS032 using ammonium chloride as the sole nitrogen source.

    PubMed

    Kekez, B D; Gojgic-Cvijovic, G D; Jakovljevic, D M; Stefanovic Kojic, J R; Markovic, M D; Beskoski, V P; Vrvic, M M

    2015-03-01

    In this study, levan production by Bacillus licheniformis NS032 isolated from a petroleum sludge sample was investigated. High levan yield was obtained in a wide range of sucrose concentrations (up to 400 g/L) and, contrary to most levan-producing strains, using ammonium chloride as the sole N source. Interaction between sucrose, ammonium chloride, and initial pH of the medium in a low sucrose (60-200 g/L) and a high sucrose (300-400 g/L) system was analyzed by response surface methodology. According to the calculated model in the low sucrose system, maximum predicted levan yield was 47.8 g/L (sucrose 196.8 g/L, ammonium chloride 2.4 g/L, pH 7.0), while in the high sucrose system, levan yield was 99.2 g/L (sucrose 397.6 g/L, ammonium chloride 4.6 g/L, pH 7.4). In addition, protective effect of microbial levan against copper toxicity to Daphnia magna is observed for the first time. The acute toxicity (48 h EC50) of copper decreased from 0.14 to 0.44 mg/L by levan in concentration of 50 ppm. PMID:25592434

  1. Combined Hydrous Ferric Oxide and Quaternary Ammonium Surfactant Tailoring of Granular Activated Carbon for Concurrent Arsenate and Perchlorate Removal

    SciTech Connect

    Jang, M.; Cannon, F; Parette, R; Yoon, S; Chen, W

    2009-01-01

    Activated carbon was tailored with both iron and quaternary ammonium surfactants so as to concurrently remove both arsenate and perchlorate from groundwater. The iron (hydr)oxide preferentially removed the arsenate oxyanion but not perchlorate; while the quaternary ammonium preferentially removed the perchlorate oxyanion, but not the arsenate. The co-sorption of two anionic oxyanions via distinct mechanisms has yielded intriguing phenomena. Rapid small-scale column tests (RSSCTs) with these dually prepared media employed synthetic waters that were concurrently spiked with arsenate and perchlorate; and these trial results showed that the quaternary ammonium surfactants enhanced arsenate removal bed life by 25-50% when compared to activated carbon media that had been preloaded merely with iron (hydr)oxide; and the surfactant also enhanced the diffusion rate of arsenate per the Donnan effect. The authors also employed natural groundwater from Rutland, MA which contained 60 microg/L As and traces of silica, and sulfate; and the authors spiked this with 40 microg/L perchlorate. When processing this water, activated carbon that had been tailored with iron and cationic surfactant could treat 12,500 bed volumes before 10 microg/L arsenic breakthrough, and 4500 bed volumes before 6 microg/L perchlorate breakthrough. Although the quaternary ammonium surfactants exhibited only a slight capacity for removing arsenate, these surfactants did facilitate a more favorably positively charged avenue for the arsenate to diffuse through the media to the iron sorption site (i.e. via the Donnan effect).

  2. Quaternary ammonium silane-functionalized, methacrylate resin composition with antimicrobial activities and self-repair potential

    PubMed Central

    Gong, Shi-qiang; Niu, Li-na; Kemp, Lisa K.; Yiu, Cynthia K.Y.; Ryou, Heonjune; Qi, Yi-pin; Blizzard, John D.; Nikonov, Sergey; Brackett, Martha G.; Messer, Regina L.W.; Wu, Christine D.; Mao, Jing; Brister, L. Bryan; Rueggeberg, Frederick A.; Arola, Dwayne D.; Pashley, David H.; Tay, Franklin R.

    2012-01-01

    Design of antimicrobial polymers for enhancing healthcare issues and minimizing environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol-gel chemical route; these compounds possess flexible Si-O-Si bonds. In present work, a partially-hydrolyzed QAMS copolymerized with bis-GMA is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. Kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) and Candida albicans (ATCC 90028). Improved mechanical properties after hydration provided the proof-of-concept that QAMS-incorporated resin exhibits self-repair potential via water-induced condensation of organic modified silicate (ormosil) phases within the polymerized resin matrix. PMID:22659173

  3. Efflux pump induction by quaternary ammonium compounds and fluoroquinolone resistance in bacteria.

    PubMed

    Buffet-Bataillon, Sylvie; Tattevin, Pierre; Maillard, Jean-Yves; Bonnaure-Mallet, Martine; Jolivet-Gougeon, Anne

    2016-01-01

    Biocides, primarily those containing quaternary ammonium compounds (QAC), are heavily used in hospital environments and various industries (e.g., food, water, cosmetic). To date, little attention has been paid to potential implications of QAC use in the emergence of antibiotic resistance, especially fluoroquinolone-resistant bacteria in patients and in the environment. QAC-induced overexpression of efflux pumps can lead to: cross resistance with fluoroquinolones mediated by multidrug efflux pumps; stress response facilitating mutation in the Quinolone Resistance Determining Region; and biofilm formation increasing the risk of transfer of mobile genetic elements carrying fluoroquinolone or QAC resistance determinants. By following the European Biocidal Product Regulation, manufacturers of QAC are required to ensure that their QAC-based biocidal products are safe and will not contribute to emerging bacterial resistance. PMID:26674470

  4. Perfluorinated quaternary ammonium salts of polyoxometalate anions: Fluorous biphasic oxidation catalysis with and without fluorous solvents

    SciTech Connect

    Maayan, Galia; Fish, Richard H.; Neumann, Ronny

    2003-05-28

    Perfluorinated quaternary ammonium cations, [CF{sub 3}(CF{sub 2}){sub 7}(CH{sub 2}){sub 3}]{sub 3}CH{sub 3}N{sup +} (RFN{sup +}), were synthesized and used as counter cations for the [WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW{sub 9}O{sub 34}){sub 2}]{sup 12-} (M = Mn(II), Zn(II)), polyoxometalate. The (RFN{sup +}){sub 12}[WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW9O{sub 34}){sub 2}] compounds were fluorous biphasic catalysts for alcohol and alkenol oxidation, and alkene epoxidation with aqueous hydrogen peroxide. Reaction protocols with or without a fluorous solvent were tested. The catalytic activity and selectivity was affected both by the hydrophobicity of the solvent and the substrate.

  5. Low Temperature Double-Layer Capacitors Using Asymmetric and Spiro-Type Quaternary Ammonium Salts

    NASA Technical Reports Server (NTRS)

    Brandon, Erik J. (Inventor); Smart, Marshall C. (Inventor); West, William C. (Inventor)

    2014-01-01

    Double-layer capacitors capable of operating at extremely low temperatures (e.g., as low as -80.degree. C.) are disclosed. Electrolyte solutions combining a base solvent (e.g., acetonitrile) and a cosolvent are employed to lower the melting point of the base electrolyte. Example cosolvents include methyl formate, ethyl acetate, methyl acetate, propionitrile, butyronitrile, and 1,3-dioxolane. A quaternary ammonium salt including at least one of triethylmethylammonium tetrafluoroborate (TEMATFB) and spiro-(1,1')-bipyrrolidium tetrafluoroborate (SBPBF.sub.4), is used in an optimized concentration (e.g., 0.10 M to 0.75 M), dissolved into the electrolyte solution. Conventional device form factors and structural elements (e.g., porous carbon electrodes and a polyethylene separator) may be employed.

  6. Bio-based ionic liquid crystalline quaternary ammonium salts: properties and applications.

    PubMed

    Sasi, Renjith; Rao, Talasila P; Devaki, Sudha J

    2014-03-26

    In the present work, we describe the preparation, properties, and applications of novel ionic liquid crystalline quaternary ammonium salts (QSs) of 3-pentadecylphenol, a bio-based low-cost material derived from cashew nut shell liquid. Amphotropic liquid crystalline phase formation in QSs was characterized using a combination of techniques, such as DSC, PLM, XRD, SEM, and rheology, which revealed the formation of one, two, and three dimensionally ordered mesophases in different length scales. On the basis of these results, a plausible mechanism for the formation of specific modes of packing in various mesophases was proposed. Observation of anisotropic ionic conductivity and electrochemical stability suggests their application as a solid electrolyte. PMID:24571658

  7. Supramolecular assembly of borate with quaternary ammonium: Crystal structure and tunable luminescent properties

    SciTech Connect

    Liang, Jie; Wang, Yong-gang; Wang, Ying-xia; Liao, Fu-hui; Lin, Jian-hua

    2013-04-15

    A new borate [C{sub 6}H{sub 16}N][B{sub 5}O{sub 6}(OH){sub 4}] (1) is synthesized hydrothermally by the reaction of isopropyltrimethylammonium hydroxide with boric acid. It crystallizes in the triclinic space group P-1 with the parameters a=9.1578(10) Å, b=9.372(9) Å, c=9.9812(10) Å, ?=66.508(2)°, ?=74.751(2)°, ?=81.893(2)°. The [B{sub 5}O{sub 6}(OH){sub 4}]{sup ?} anions are interlinked via hydrogen bonding forming a 3D supramolecular network containing large cavities, where reside the (CH{sub 3}){sub 3}(i-C{sub 3}H{sub 7}) N{sup +} cations. This borate shows tunable luminescent properties with temperature, heating-treatment, exciting-light, and solvents. The fluorescent intensity of 1 enhances 6-fold with decreasing the temperature from 25 K to 78 K. By treatment under different temperatures, the luminescence of 1 shifted from blue to white and the sample treated at 230 °C emits bright white light to naked eyes. The hybrid borate can disperse in different solvents, and shows a red-shifted and intense emission in polar solvents. - Graphical abstract: The new quaternary ammonium borate [C{sub 6}H{sub 17}N][B{sub 5}O{sub 6}(OH){sub 4}] contains a 3D supramolecular network formed by hydrogen bond linked [B{sub 5}O{sub 6}(OH){sub 4}]{sup ?} anions and shows tunable luminescent properties with temperature, excitation light, and solvents. Highlights: ? A novel quaternary ammonium borate was synthesized. ? It possesses a supramolecular network fomed by H-bonded [B{sub 5}O{sub 6}(OH){sub 4}]{sup ?} anions. ? This borate shows tunable luminescent properties with temperature, heating treatment, excitation light, and solvents.

  8. Dental primer and adhesive containing a new antibacterial quaternary ammonium monomer dimethylaminododecyl methacrylate

    PubMed Central

    Cheng, Lei; Weir, Michael D.; Zhang, Ke; Arola, Dwayne D.; Zhou, Xuedong; Xu, Hockin H. K.

    2013-01-01

    Objectives The main reason for restoration failure is secondary caries caused by biofilm acids. Replacing the failed restorations accounts for 50–70% of all operative work. The objectives of this study were to incorporate a new quaternary ammonium monomer (dimethylaminododecyl methacrylate, DMADDM) and nanoparticles of silver (NAg) into a primer and an adhesive, and to investigate their effects on antibacterial and dentin bonding properties. Methods Scotchbond Multi-Purpose (SBMP) served as control. DMADDM was synthesized and incorporated with NAg into primer/adhesive. A dental plaque microcosm biofilm model with human saliva was used to investigate metabolic activity, colony-forming units (CFU), and lactic acid. Dentin shear bond strengths were measured. Results Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the new DMADDM were orders of magnitude lower than those of a previous quaternary ammonium dimethacrylate (QADM). Uncured primer with DMADDM had much larger inhibition zones than QADM (p<0.05). Cured primer/adhesive with DMADDM-NAg greatly reduced biofilm metabolic activity (p<0.05). Combining DMADDM with NAg in primer/adhesive resulted in less CFU than DMADDM alone (p<0.05). Lactic acid production by biofilms was reduced by 20-fold via DMADDM-NAg, compared to control. Incorporation of DMADDM and NAg into primer/adhesive did not adversely affect dentin bond strength. Conclusions A new antibacterial monomer DMADDM was synthesized and incorporated into primer/adhesive for the first time. The bonding agents are promising to combat residual bacteria in tooth cavity and invading bacteria at tooth-restoration margins to inhibit caries. DMADDM and NAg are promising for use into a wide range of dental adhesive systems and restoratives. PMID:23353068

  9. Synthesis and characterization of chitosan quaternary ammonium salt and its application as drug carrier for ribavirin.

    PubMed

    Li, Si-Dong; Li, Pu-Wang; Yang, Zi-Ming; Peng, Zheng; Quan, Wei-Yan; Yang, Xi-Hong; Yang, Lei; Dong, Jing-Jing

    2014-11-01

    N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) is hydro-soluble chitosan (CS) derivative, which can be obtained by the reaction between epoxypropyl trimethyl ammonium chloride (ETA) and CS. The preparation parameters for the synthesis of HTCC were optimized by orthogonal experimental design. ETA was successfully grafted into the free amino group of CS. Grafting of ETA with CS had great effect on the crystal structure of HTCC, which was confirmed by the XRD results. HTCC displayed higher capability to form nanoparticles by crosslinking with negatively charged sodium tripolyphosphate (TPP). Ribavrin- (RIV-) loaded HTCC nanoparticles were positively charged and were spherical in shape with average particle size of 200?nm. More efficient drug encapsulation efficiency and loading capacity were obtained for HTCC in comparison with CS, however, HTCC nanoparticles displayed faster release rate due to its hydro-soluble properties. The results suggest that HTCC is a promising CS derivative for the encapsulation of hydrophilic drugs in obtaining sustained release of drugs. PMID:24215307

  10. Effect of ten quaternary ammonium cations on tetrachloromethane sorption to clay from water

    USGS Publications Warehouse

    Smith, J.A.

    1990-01-01

    The mineral surface of Wyoming bentonite (clay) was modified by replacing inorganic ions by each of 10 quaternary ammonium compounds, and tetrachloromethane sorption to the modified sorbents from water was studied. Tetrachloromethane sorption from solution to clay modified with tetramethyl-, tetraethyl-, benzyltrimethyl-, or benzyltriethylammonium cations generally is characterized by relatively high solute uptake, isotherm nonlinearity, and competitive sorption (with trichloroethene as the competing sorbate). For these sorbents, the ethyl functional groups yield reduced sorptive capacity relative to methyl groups, whereas the benzyl group appears to have a similar effect on sorbent capacity as the methyl group. Sorption of tetrachloromethane to clay modified with dodecyldimethyl(2-phenoxyethyl)-, dodecyltrimethyl-, tetradecyltrimethyl-, hexadecyltrimethyl-, or benzyldimethylhexadecylammonium bromide is characterized by relatively low solute uptake, isotherm linearity, and noncompetitive sorption. For these sorbents, an increase in the size of the nonpolar functional group(s) causes an increase in the organic carbon normalized sorption coefficient (Koc). No measurable uptake of tetrachloromethane sorption by the unmodified clay or clay modified by ammonium bromide was observed. ?? 1990 American Chemical Society.

  11. Quaternary ammonium salts with tetrafluoroborate anion: Phytotoxicity and oxidative stress in terrestrial plants.

    PubMed

    Biczak, Robert

    2016-03-01

    This paper discusses the impact of four quaternary ammonium salts (QAS) such as tetraethylammonium tetrafluoroborate [TEA][BF4], tetrabutylammonium tetrafluoroborate [TBA][BF4], tetrahexylammonium tetrafluoroborate [THA][BF4], and tetraoctylammonium tetrafluoroborate [TOA][BF4] on the growth and development of spring barley and common radish. Analogous tests were performed with the inorganic salt ammonium tetrafluoroborate [A][BF4] for comparison purposes. Results indicated that the phytotoxicity of the QAS applied is dependent on the concentration of the substance and their number of carbon atoms. The most toxic compound was [TBA][BF4], causing the greatest drop in fresh weight of both study plants, similar to the phytotoxic effects of [A][BF4]. All the tested compounds caused oxidative stress in spring barley and common radish seedlings due to a drop in the chlorophyll content. Stress was also observed in plants, which was indicated by the increased level of ROS (reactive oxygen species) such as H2O2 and lipid peroxidation of MDA (malondialdehyde). Due to the stress, both plants displayed changes in the activity of antioxidative enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). Based on the results of the study, it was concluded that changes in chlorophyll levels and peroxidase activity are the best biomarkers to determine oxidative stress in plants. PMID:26551221

  12. Radiation Stability of Benzyl Tributyl Ammonium Chloride towards Technetium-99 Extraction - 13016

    SciTech Connect

    Paviet-Hartmann, Patricia; Horkley, Jared; Campbell, Keri; Roman, Audrey; Nunez, Ana; Espartero, Amparo

    2013-07-01

    A closed nuclear fuel cycle combining new separation technologies along with generation III and generation IV reactors is a promising way to achieve a sustainable energy supply. But it is important to keep in mind that future recycling processes of used nuclear fuel (UNF) must minimize wastes, improve partitioning processes, and integrate waste considerations into processes. New separation processes are being developed worldwide to complement the actual industrialized PUREX process which selectively separates U(VI) and Pu(IV) from the raffinate. As an example, the UREX process has been developed in the United States to co-extract hexavalent uranium (U) and hepta-valent technetium (Tc) by tri-n-butyl phosphate (TBP). Tc-99 is recognized to be one of the most abundant, long-lived radio-toxic isotopes in UNF (half-life, t{sub 1/2} = 2.13 x 10{sup 5} years), and as such, is targeted in UNF separation strategies for isolation and encapsulation in solid waste-forms for final disposal in a nuclear waste repository. Immobilization of Tc-99 by a durable solid waste-form is a challenge, and its fate in new advanced technology processes is of importance. It is essential to be able to quantify and locate 1) its occurrence in any new developed flowsheets, 2) its chemical form in the individual phases of a process, 3) its potential quantitative transfer in any waste streams, and consequently, 4) its quantitative separation for either potential transmutation to Ru-100 or isolation and encapsulation in solid waste-forms for ultimate disposal. In addition, as a result of an U(VI)-Tc(VII) co-extraction in a UREX-based process, Tc(VII) could be found in low level waste (LLW) streams. There is a need for the development of new extraction systems that would selectively extract Tc-99 from LLW streams and concentrate it for feed into high level waste (HLW) for either Tc-99 immobilization in metallic waste-forms (Tc-Zr alloys), and/or borosilicate-based waste glass. Studies have been launched to investigate the suitability of new macro-compounds such as crown-ethers, aza-crown ethers, quaternary ammonium salts, and resorcin-arenes for the selective extraction of Tc-99 from nitric acid solutions. The selectivity of the ligand is important in evaluating potential separation processes and also the radiation stability of the molecule is essential for minimization of waste and radiolysis products. In this paper, we are reporting the extraction of TcO{sub 4}{sup -} by benzyl tributyl ammonium chloride (BTBA). Experimental efforts were focused on determining the best extraction conditions by varying the ligand's matrix conditions and concentration, as well as varying the organic phase composition (i.e. diluent variation). Furthermore, the ligand has been investigated for radiation stability. The ?-irradiation was performed on the neat organic phases containing the ligand at different absorbed doses to a maximum of 200 kGy using an external Co-60 source. Post-irradiation solvent extraction measurements will be discussed. (authors)

  13. Degradation of Imidazolium- and Quaternary Ammonium-Functionalized Poly(fluorenyl ether ketone sulfone) Anion Exchange Membranes

    SciTech Connect

    Chen, DY; Hickner, MA

    2012-11-01

    Imidazolium and quaternary ammonium-functionalized poly(fluorenyl ether ketone sulfone)s were synthesized successfully with the same degree of cationic functionalization and identical polymer backbones for a comparative study of anion exchange membranes (AEMs) for solid-state alkaline membrane fuel cells (AMFCs). Both anion exchange membranes were synthesized using a new methyl-containing monomer that avoided the use of toxic chloromethylation reagents. The polymer chemical structures were confirmed by H-1 NMR and FTIR. The derived AEMs were fully characterized by water uptake, anion conductivity, stability under aqueous basic conditions, and thermal stability. Interestingly, both the cationic groups and the polymer backbone were found to be degraded in 1 M NaOH solution at 60 degrees C over 48 h as measured by changes of ion exchange capacity and intrinsic viscosity. Imidazolium-functionalized poly(fluorenyl ether ketone sulfone)s had similar aqueous alkaline stability to quaternary ammonium-functionalized materials at 60 degrees C but much lower stability at 80 degrees C. This work demonstrates that quaternary ammonium and imidazolium cationic groups are not stable on poly(arylene ether sulfone) backbones under relatively mild conditions. Additionally, the poly(arylene ether sulfone) backbone, which is one of the most common polymers used in ion exchange membrane applications, is not stable in the types of molecular configurations analyzed.

  14. Effect of charge density of bonding agent containing a new quaternary ammonium methacrylate on antibacterial and bonding properties

    PubMed Central

    Li, Fang; Weir, Michael D.; Chen, Jihua; Xu, Hockin H. K.

    2014-01-01

    Objectives Quaternary amine charge density is important because when the negatively-charged bacteria contact the positive quaternary amine charge, the electric balance is disturbed and the bacterium could be disrupted. There has been no report on the effects of charge density on the antibacterial efficacy of dental bonding agents. The objective of this study was to synthesize a new quaternary ammonium methacrylate, and investigate the effects of charge density of bonding agent on bacteria early-attachment, biofilm colony-forming units (CFU) and dentin bond strength. Methods Dimethylaminododecyl methacrylate (DMAHDM) with an alkyl chain length of 16 was synthesized and mixed into Scotchbond Multi-Purpose adhesive and primer (SBMP) at mass fractions of 0%, 2.5%, 5%, 7.5%, and 10%. A microtensile dentin bond test was performed. The density of quaternary ammonium groups was measured using a fluorescein dye method. Streptococcus mutans (S. mutans) early-attachment was examined at 4 hours, and biofilm colony-forming units (CFU) were measured at 2 days. Results All groups had similar microtensile bonding strengths (mean ± sd; n = 40) of about 60 MPa (p > 0.1). Quaternary amine charge density of bonding agents monotonically increased with increasing DMAHDM mass fraction. Bacteria early-attachment coverage greatly decreased with increasing DMAHDM content in the resin. Biofilm CFU at 10% DMAHDM was reduced by almost 5 log, compared to SBMP control. Charge density of bonding agent was inversely proportional to bacteria early-attachment coverage and biofilm CFU. Significance Increasing the quaternary amine charge density of dentin bonding agent resin was shown to greatly reduce S. mutans attachment and decrease biofilm CFU by four orders of magnitude, without compromising the dentin bond strength. The new DMAHDM is promising for use in bonding agents and other antibacterial restorative materials to inhibit caries. PMID:24534376

  15. Antibacterial Activity, in Vitro Cytotoxicity, and Cell Cycle Arrest of Gemini Quaternary Ammonium Surfactants.

    PubMed

    Zhang, Shanshan; Ding, Shiping; Yu, Jing; Chen, Xuerui; Lei, Qunfang; Fang, Wenjun

    2015-11-10

    Twelve gemini quaternary ammonium surfactants have been employed to evaluate the antibacterial activity and in vitro cytotoxicity. The antibacterial effects of the gemini surfactants are performed on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with minimum inhibitory concentrations (MIC) ranging from 2.8 to 167.7 ?M. Scanning electron microscopy (SEM) analysis results show that these surfactants interact with the bacterial cell membrane, disrupt the integrity of the membrane, and consequently kill the bacteria. The data recorded on C6 glioma and HEK293 human kidney cell lines using an MTT assay exhibit low half inhibitory concentrations (IC50). The influences of the gemini surfactants on the cell morphology, the cell migration ability, and the cell cycle are observed through hematoxylin-eosin (HE) staining, cell wound healing assay, and flow cytometric analyses, respectively. Both the values of MIC and IC50 decrease against the growth of the alkyl chain length of the gemini surfactants with the same spacer group. In the case of surfactants 12-s-12, the MICs and IC50s are found to decrease slightly with the spacer chain length changing from 2 to 8 and again to increase at higher spacer length (s = 10-12). All of the gemini surfactants show great antibacterial activity and cytotoxicity, and they might exhibit potential applications in medical fields. PMID:26474336

  16. Quaternary ammonium compounds (QACs): a review on occurrence, fate and toxicity in the environment.

    PubMed

    Zhang, Chang; Cui, Fang; Zeng, Guang-ming; Jiang, Min; Yang, Zhong-zhu; Yu, Zhi-gang; Zhu, Meng-ying; Shen, Liu-qing

    2015-06-15

    Quaternary ammonium compounds (QACs) are widely applied in household and industrial products. Most uses of QACs can be expected to lead to their release to wastewater treatment plants (WWTPs) and then dispersed into various environmental compartments through sewage effluent and sludge land application. Although QACs are considered to be aerobically biodegradable, the degradation is affected by its chemical structures, dissolved oxygen concentration, complexing with anionic surfactants, etc. High abundance of QACs has been detected in sediment and sludge samples due to its strong sorption and resistance to biodegradation under anoxic/anaerobic conditions. QACs are toxic to a lot of aquatic organisms including fish, daphnids, algae, rotifer and microorganisms employed in wastewater treatment systems. And antibiotic resistance has emerged in microorganisms due to excessive use of QACs in household and industrial applications. The occurrence of QACs in the environment is correlated with anthropogenic activities, such as wastewater discharge from WWTPs or single source polluters, and sludge land application. This article also reviews the analytical methods for determination of QACs in environmental compartments including surface water, wastewater, sewage sludge and sediments. PMID:25770948

  17. Anti-biofilm Dentin Primer with Quaternary Ammonium and Silver Nanoparticles

    PubMed Central

    Cheng, L.; Zhang, K.; Melo, M.A.S.; Weir, M.D.; Zhou, X.; Xu, H.H.K.

    2012-01-01

    Antibacterial bonding agents could combat recurrent caries at the tooth-composite margins. The objectives of this study were to develop novel antibacterial dentin primers containing quaternary ammonium dimethacrylate (QADM) and nanoparticles of silver (NAg), and to investigate the effects on dentin bond strength and dental plaque microcosm biofilms for the first time. Scotchbond Multi-Purpose (“SBMP”) bonding agent was used. QADM and NAg were incorporated into SBMP primer, yielding 4 primers: SBMP primer (control), control + 10% QADM (mass), control + 0.05% NAg, and control + 10% QADM + 0.05% NAg. Human saliva was collected to grow microcosm biofilms. The NAg particle size (mean ± SD; n = 100) was 2.7 ± 0.6 nm. Dentin shear bond strengths (n = 10) with human third molars were approximately 30 MPa for all groups (p > 0.1). QADM-NAg-containing primer increased the bacteria inhibition zone by 9-fold, compared with control primer (p < 0.05). QADM-NAg-containing primer reduced lactic acid production and colony-forming units of total micro-organisms, total streptococci, and mutans streptococci by an order of magnitude. In conclusion, novel QADM-NAg-containing primers were strongly antibacterial without compromising dentin bond strength, and hence are promising to inhibit biofilms and secondary caries. The processing method of incorporating QADM and NAg together into the same primer produced the strongest antibacterial effect, which could have a wide applicability to other bonding systems. PMID:22492276

  18. Fluorosilicone multi-block copolymers tethering quaternary ammonium salt groups for antimicrobial purpose

    NASA Astrophysics Data System (ADS)

    Zhou, Fang; Qin, Xiaoshuai; Li, Yancai; Ren, Lixia; Zhao, Yunhui; Yuan, Xiaoyan

    2015-08-01

    Symmetrically structured fluorosilicone multi-block copolymers containing poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(hexafluorobutyl methacrylate) (PHFBMA) were sequentially synthesized via reversible addition-fragmentation chain transfer polymerization, using a polydimethylsiloxane (PDMS) chain transfer agent with dithiocarbonate groups at both ends. Then, the CBABC-type block copolymers were quaternized with n-octyliodide to tether quaternary ammonium salt (QAS) groups in the PDMAEMA blocks for the antimicrobial use. The obtained fluorosilicone copolymers showed clear variations in the C-N+ composition and surface morphology on their films depending on the content of the PHFBMA blocks, which were characterized by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. The results indicated that the symmetrical CBABC structure favored PDMS and QAS tethered blocks migrating to the film surface. With the mass percentage of the PHFBMA increased from 0 to 32.5%, the surface roughness of the copolymer film decreased gradually with a tendency to form a smooth surface. Owing to the surface properties, fluorosilicone multi-block copolymers containing a certain amount of PHFBMA with higher C-N+ content and relatively smooth morphology demonstrated obvious antimicrobial activity against Gram-positive bacteria, Bacillus subtilis and Gram-negative bacteria, Escherichia coli. The functionalized multi-block copolymers based on fluorosilicone and QAS groups would have potential applications in antimicrobial coatings.

  19. Antimicrobial evaluation of quaternary ammonium polyethyleneimine nanoparticles against clinical isolates of pathogenic bacteria.

    PubMed

    Ortega, Agustín; Farah, Shady; Tranque, Pedro; Ocaña, Ana V; Nam-Cha, Syong H; Beyth, Nurit; Gómez-Roldán, Carmen; Pérez-Tanoira, Ramón; Domb, Abraham J; Pérez-Martínez, Francisco C; Pérez-Martínez, Juan

    2015-12-01

    Peritonitis is a disease caused by bacterial strains that have become increasingly resistant to many antibiotics. The development of alternative therapeutic compounds is the focus of extensive research, so novel nanoparticles (NPs) with activity against antibiotic-resistant bacteria should be developed. In this study, the antibacterial activity of quaternary ammonium polyethyleneimine (QA-PEI) NPs was evaluated against Streptococcus viridans, Stenotrophomonas maltophilia and Escherichia coli. To appraise the antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration and bactericidal assays were utilised with different concentrations (1.56-100 µg/ml) of QA-PEI NPs. Moreover, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and annexin V/propidium iodide toxicity assays were performed in cell cultures. MICs for S. maltophilia and E. coli isolates were 12.5 and 25 µg/ml, respectively, whereas the MIC for S. viridans was 100 µg/ml. Furthermore, the growth curve assays revealed that these QA-PEI NPs at a concentration of 12.5 µg/ml significantly inhibited bacterial growth for the bacterial isolates studied. On the other hand, QA-PEI NPs lacked significant toxicity for cells when used at concentrations up to 50 ?g/ml for 48 h. The present findings reveal the potential therapeutic value of this QA-PEI NPs as alternative antibacterial agents for peritonitis, especially against Gram-negative bacteria. PMID:26647809

  20. Hygroscopicity and evaporation of ammonium chloride and ammonium nitrate: Relative humidity and size effects on the growth factor

    NASA Astrophysics Data System (ADS)

    Hu, Dawei; Chen, Jianmin; Ye, Xingnan; Li, Ling; Yang, Xin

    2011-05-01

    The hygroscopicity and evaporation of ammonium chloride and ammonium nitrate in the size range of 40-200 nm are investigated from 20% to 86% RH using a self-assembled hygroscopic tandem differential mobility analyzer (H-TDMA) system. The hygroscopicity of 100 nm (NH 4) 2SO 4 is also measured for comparison. The measured hygroscopic growth factors (GFs) of (NH 4) 2SO 4 agree well with the theoretical Köhler curve. Great discrepancies between the measured GFs and the theoretical values are observed for NH 4Cl and NH 4NO 3 due to their volatile properties. The evaporation of NH 4Cl below the deliquescence RH (DRH) is significantly promoted while RH increases. Similar trend is also observed for NH 4NO 3 particle less than 50 nm. The proposed mechanism suggests that the increase of RH alters the chemical equilibrium among NH 4X (s) (X represents Cl - or NO 3-), NH 3(g) and HX (g), i.e., NHX?NH+HX, by converting NH 3(g) and HX (g) into NH 3·nH 2O and HX·nH 2O, which accelerates the evaporation of NH 4X (s). When RH is higher than the DRH, the GFs of NH 4X increase with initial particle size ( D0) throughout the investigated size range. In this study, the iso-GF curves are also drawn to illustrate the effects of D0 and RH on the GFs. Different from (NH 4) 2SO 4, NaCl, Na 2SO 4 and NaNO 3, the GFs of NH 4X are more sensitive to D0 than RH due to the unique volatility of NH 4Cl and NH 4NO 3 particles.

  1. Identification of quaternary ammonium compounds as potent inhibitors of hERG potassium channels

    SciTech Connect

    Xia Menghang; Shahane, Sampada A.; Huang, Ruili; Titus, Steven A.; Shum, Enoch; Zhao Yong; Southall, Noel; Zheng, Wei; Witt, Kristine L.; Tice, Raymond R.; Austin, Christopher P.

    2011-05-01

    The human ether-a-go-go-related gene (hERG) channel, a member of a family of voltage-gated potassium (K{sup +}) channels, plays a critical role in the repolarization of the cardiac action potential. The reduction of hERG channel activity as a result of adverse drug effects or genetic mutations may cause QT interval prolongation and potentially leads to acquired long QT syndrome. Thus, screening for hERG channel activity is important in drug development. Cardiotoxicity associated with the inhibition of hERG channels by environmental chemicals is also a public health concern. To assess the inhibitory effects of environmental chemicals on hERG channel function, we screened the National Toxicology Program (NTP) collection of 1408 compounds by measuring thallium influx into cells through hERG channels. Seventeen compounds with hERG channel inhibition were identified with IC{sub 50} potencies ranging from 0.26 to 22 {mu}M. Twelve of these compounds were confirmed as hERG channel blockers in an automated whole cell patch clamp experiment. In addition, we investigated the structure-activity relationship of seven compounds belonging to the quaternary ammonium compound (QAC) series on hERG channel inhibition. Among four active QAC compounds, tetra-n-octylammonium bromide was the most potent with an IC{sub 50} value of 260 nM in the thallium influx assay and 80 nM in the patch clamp assay. The potency of this class of hERG channel inhibitors appears to depend on the number and length of their aliphatic side-chains surrounding the charged nitrogen. Profiling environmental compound libraries for hERG channel inhibition provides information useful in prioritizing these compounds for cardiotoxicity assessment in vivo.

  2. Identification of quaternary ammonium compounds as potent inhibitors of hERG potassium channels

    PubMed Central

    Xia, Menghang; Shahane, Sampada; Huang, Ruili; Titus, Steven A.; Shum, Enoch; Zhao, Yong; Southall, Noel; Zheng, Wei; Witt, Kristine L.; Tice, Raymond R.; Austin, Christopher P.

    2011-01-01

    The human ether-a-go-go-related gene (hERG) channel, a member of a family of voltage-gated potassium (K+) channels, plays a critical role in the repolarization of the cardiac action potential. The reduction of hERG channel activity as a result of adverse drug effects or genetic mutations may cause QT interval prolongation and potentially lead to acquired long QT syndrome. Thus, screening for hERG channel activity is important in drug development. Cardiotoxicity associated with the inhibition of hERG channels by environmental chemicals is also a public health concern. To assess the inhibitory effects of environmental chemicals on hERG channel function, we screened the National Toxicology Program (NTP) collection of 1408 compounds by measuring thallium influx into cells through hERG channels. Seventeen compounds with hERG channel inhibition were identified with IC50 potencies ranging from 0.26 to 22 ?M. Twelve of these compounds were confirmed as hERG channel blockers in an automated whole cell patch clamp experiment. In addition, we investigated the structure-activity relationship of seven compounds belonging to the quaternary ammonium compound (QAC) series on hERG channel inhibition. Among four active QAC compounds, tetra-n-octylammonium bromide was the most potent with an IC50 value of 260 nM in the thallium influx assay and 80 nM in the patch clamp assay. The potency of this class of hERG channel inhibitors appears to depend on the number and length of their aliphatic side-chains surrounding the charged nitrogen. Profiling environmental compound libraries for hERG channel inhibition provides information useful in prioritizing these compounds for cardiotoxicity assessment in vivo. PMID:21362439

  3. Sanitizing in Dry-Processing Environments Using Isopropyl Alcohol Quaternary Ammonium Formula.

    PubMed

    Kane, Deborah M; Getty, Kelly J K; Mayer, Brian; Mazzotta, Alejandro

    2016-01-01

    Dry-processing environments are particularly challenging to clean and sanitize because introduced water can favor growth and establishment of pathogenic microorganisms such as Salmonella. Our objective was to determine the efficacy of an isopropyl alcohol quaternary ammonium (IPAQuat) formula for eliminating potential Salmonella contamination on food contact surfaces. Clean stainless steel coupons and conveyor belt materials used in dry-processing environments were spot inoculated in the center of coupons (5 by 5 cm) with a six-serotype composite of Salmonella (approximately 10 log CFU/ml), subjected to IPAQuat sanitizer treatments with exposure times of 30 s, 1 min, or 5 min, and then swabbed for enumeration of posttreatment survivors. A subset of inoculated surfaces was soiled with a breadcrumb-flour blend and allowed to sit on the laboratory bench for a minimum of 16 h before sanitation. Pretreatment Salmonella populations (inoculated controls, 0 s treatment) were approximately 7.0 log CFU/25 cm(2), and posttreatment survivors were 1.31, 0.72, and < 0.7 (detection limit) log CFU/25 cm(2) after sanitizer exposure for 30 s, 1 min, or 5 min, respectively, for both clean (no added soil) and soiled surfaces. Treatment with the IPAQuat formula using 30-s sanitizer exposures resulted in 5.68-log reductions, whereas >6.0-log reductions were observed for sanitizer exposures of 1 and 5 min. Because water is not introduced into the processing environment with this approach, the IPAQuat formula could have sanitation applications in dry-processing environments to eliminate potential contamination from Salmonella on food contact surfaces. PMID:26735036

  4. Comparing effectiveness of rhamnolipid biosurfactant with a quaternary ammonium salt surfactant for hydrate anti-agglomeration.

    PubMed

    York, J Dalton; Firoozabadi, Abbas

    2008-01-24

    Natural gas is projected to be the premium fuel of the 21st century because of availability, as well as economical and environmental considerations. Natural gas is coproduced with water from the subsurface forming gas hydrates. Hydrate formation may result in shutdown of onshore and offshore operations. Industry practice has been usage of alcohols--which have undesirable environmental impacts--to affect bulk-phase properties and inhibit hydrate formation. An alternative to alcohols is changing the surface properties through usage of polymers and surfactants, effective at 0.5-3 wt % of coproduced water. One group of low-dosage hydrate inhibitors (LDHI) are kinetic inhibitors, which affect nucleation rate and growth. A second group of LDHI are anti-agglomerants, which prevent agglomeration of small hydrate crystallites. Despite great potential, reported work on hydrate anti-agglomeration is very limited. In this paper, our focus is on the use of two vastly different surfactants as anti-agglomerants. We use a model oil, water, and tetrahydrofuran as a hydrate-forming species. We examine the effectiveness of a quaternary ammonium salt (i.e., quat). Visual observation measurements show that a small concentration of the quat (0.01%) can prevent agglomeration. However, a quat is not a green chemical and therefore may be undesirable. We show that a rhamnolipid biosurfactant can be effective to a concentration of 0.05 wt %. One difference between the two surfactants is the stability of the water-in-oil emulsions created. The biosurfactant forms a less stable emulsion, which makes it very desirable for hydrate application. PMID:18171051

  5. Synthesis, growth and characterization of nonlinear optical urea-ammonium chloride crystals

    NASA Astrophysics Data System (ADS)

    Chithambaram, V.; Das, S. Jerome; Nambi, R. Arivudai; Krishnan, S.

    2012-02-01

    Semi-organic nonlinear optical urea-ammonium chloride (UAC) crystals have been grown from aqueous solution by slow evaporation technique. The lattice parameters of the grown crystals were determined by X-ray diffraction studies. The presence of functional groups was determined using Fourier transform infrared (FTIR) analysis. The thermal analysis studies indicate that the material possess optimum thermal stability. Optical absorption studies show low absorption in the entire visible region and UV cut - off is found to be at 240 nm. The presence of second harmonic generation (SHG) for the grown crystal was confirmed by Kurtz powder technique.

  6. Reversible Swelling of Chitosan and Quaternary Ammonium Modified Chitosan Brush Layers: Effect of pH and Counter Anion Size and Functionality

    PubMed Central

    Lee, Hyun-Su; Yee, Michael Q.; Eckmann, Yonaton Y.; Hickok, Noreen J.; Eckmann, David M.; Composto, Russell J.

    2012-01-01

    This study investigates the swelling of grafted polycationic brushes as a function of pH and anion type. The brushes are chitosan (CH) and chitosans with 27% and 51% degree of substitution (DS) of quaternary ammonium salt, denoted as CH-Q25 and CH-Q50, respectively. The water content and swelling behaviors are monitored using in situ quartz-crystal microbalance with dissipation (QCM-D). The pH varies from ~3.5 to 8.5, and the counter anion types include chloride, acetate, and citrate. At fixed pH, the water content and brush swelling increase as the DS increases. Whereas the CH-Q50 brush layer shows symmetric swelling with a minimum near pH = 4.5, the swelling of CH and CH-Q25 is relatively constant as pH decreases from 8.2 to 5.5, and then begins to increase near pH 4. These studies indicate that the symmetric swelling of CH-Q50 is likely attributed to increasing protonation of primary amines for pH values below pH 6.5 and the quaternary ammonium salts above pH 6.5. At pH 4, the swelling of the CH brush increases upon exchanging the smaller chloridewith a bulkier acetate anion, which is less effective at screening intra/inter molecular repulsion. In contrast, upon exchanging the acetate with trifunctional citrate, CH and CH-Q25 brushes collapse by 53 and 42%, respectively, because the citrate forms ionic cross-links. To test antibacterial properties, silicon oxide, CH and CH-Q50 brush layers are exposed to 107–108 cfu/ml of S. aureus for two days at 37 °C and exposed to stepped shear stresses in 2 min intervals. Whereas an S. aureus biofilm adheres strongly to silicon oxide and CH for stresses up to 12 dyne/cm2, biofilms on CH-Q50 detach at a relatively low shear stress, 1.5 dyne/cm2. Due to their high degree of swelling that can be tuned via pH, counterion size and type, chitosan and quaternary modified chitosans have potential as responsive coatings for applications including MEMS/NEMS devices and drug eluting implants. PMID:23209343

  7. Cooperative Binding of Divalent Diamides by N-Alkyl Ammonium Resorcinarene Chlorides.

    PubMed

    Beyeh, N Kodiah; Ala-Korpi, Altti; Pan, Fangfang; Jo, Hyun Hwa; Anslyn, Eric V; Rissanen, Kari

    2015-06-22

    N-Alkyl ammonium resorcinarene chlorides, stabilized by an intricate array of hydrogen bonds leading to a cavitand-like structure, bind amides. The molecular recognition occurs through intermolecular hydrogen bonds between the carbonyl oxygen and the amide hydrogen of the guests and the cation-anion circular hydrogen-bonded seam of the hosts, as well as through CH???? interactions. The N-alkyl ammonium resorcinarene chlorides cooperatively bind a series of di-acetamides of varying spacer lengths ranging from three to seven carbons. Titration data fit either a 1:1 or 2:1 binding isotherm depending on the spacer lengths. Considering all the guests possess similar binding motifs, the first binding constants were similar (K1:10(2) ?M(-1)) for each host. The second binding constant was found to depend on the upper rim substituent of the host and the spacer length of the guests, with the optimum binding observed with the six-carbon spacer (K2:10(3) ?M(-2)). Short spacer lengths increase steric hindrance, whereas longer spacer lengths increase flexibility thus reducing cooperativity. The host with the rigid cyclohexyl upper rim showed stronger binding than the host with flexible benzyl arms. The cooperative binding of these divalent guests was studied in solution through (1)H?NMR titration studies and supplemented by diffusion-ordered spectroscopy (DOSY), X-ray crystallography, and mass spectrometry. PMID:26014834

  8. Design of chiral urea-quaternary ammonium salt hybrid catalysts for asymmetric reactions of glycine Schiff bases†

    PubMed Central

    Tiffner, Maximilian; Novacek, Johanna; Busillo, Alfonso; Gratzer, Katharina; Massa, Antonio; Waser, Mario

    2015-01-01

    Bifunctional chiral urea-containing quaternary ammonium salts can be straightforwardly synthesised in good yield and with high structural diversity via a scalable and operationally simple highly telescoped sequence starting from trans-1,2-cyclohexanediamine. These novel hybrid catalysts were systematically investigated for their potential to control glycine Schiff bases in asymmetric addition reactions. It was found that Michael addition reactions and the herein presented aldol-initiated cascade reaction can be carried out to provide enantiomeric ratios up to 95 : 5 and good yields under mild conditions at room temperature. PMID:26504516

  9. Improved performance and stability of perovskite solar cells by crystal crosslinking with alkylphosphonic acid ?-ammonium chlorides

    NASA Astrophysics Data System (ADS)

    Li, Xiong; Ibrahim Dar, M.; Yi, Chenyi; Luo, Jingshan; Tschumi, Manuel; Zakeeruddin, Shaik M.; Nazeeruddin, Mohammad Khaja; Han, Hongwei; Grätzel, Michael

    2015-09-01

    In the past few years, organic-inorganic halide perovskites have rapidly emerged as promising materials for photovoltaic applications, but simultaneously achieving high performance and long-term stability has proved challenging. Here, we show a one-step solution-processing strategy using phosphonic acid ammonium additives that results in efficient perovskite solar cells with enhanced stability. We modify the surface of methylammonium lead triiodide (CH3NH3PbI3) perovskite by spin-coating its precursor solution in the presence of butylphosphonic acid 4-ammonium chloride. Morphological, structural and elemental analyses show that the phosphonic acid ammonium additive acts as a crosslink between neighbouring grains in the perovskite structure, through strong hydrogen bonding of the -PO(OH)2 and -NH3+ terminal groups to the perovskite surface. The additives facilitate the incorporation of the perovskite within a mesoporous TiO2 scaffold, as well as the growth of a uniform perovskite layer at the surface, enhancing the material's photovoltaic performance from 8.8 to 16.7% as well as its resistance to moisture.

  10. Improved performance and stability of perovskite solar cells by crystal crosslinking with alkylphosphonic acid ?-ammonium chlorides.

    PubMed

    Li, Xiong; Dar, M Ibrahim; Yi, Chenyi; Luo, Jingshan; Tschumi, Manuel; Zakeeruddin, Shaik M; Nazeeruddin, Mohammad Khaja; Han, Hongwei; Grätzel, Michael

    2015-09-01

    In the past few years, organic-inorganic halide perovskites have rapidly emerged as promising materials for photovoltaic applications, but simultaneously achieving high performance and long-term stability has proved challenging. Here, we show a one-step solution-processing strategy using phosphonic acid ammonium additives that results in efficient perovskite solar cells with enhanced stability. We modify the surface of methylammonium lead triiodide (CH3NH3PbI3) perovskite by spin-coating its precursor solution in the presence of butylphosphonic acid 4-ammonium chloride. Morphological, structural and elemental analyses show that the phosphonic acid ammonium additive acts as a crosslink between neighbouring grains in the perovskite structure, through strong hydrogen bonding of the -PO(OH)2 and -NH3(+) terminal groups to the perovskite surface. The additives facilitate the incorporation of the perovskite within a mesoporous TiO2 scaffold, as well as the growth of a uniform perovskite layer at the surface, enhancing the material's photovoltaic performance from 8.8 to 16.7% as well as its resistance to moisture. PMID:26291941

  11. Substituted Quaternary Ammonium Salts Improve Low-Temperature Performance of Double-Layer Capacitors

    NASA Technical Reports Server (NTRS)

    Brandon, Erik J.; Smart, Marshall C.; West, William C.

    2011-01-01

    Double-layer capacitors are unique energy storage devices, capable of supporting large current pulses as well as a very high number of charging and discharging cycles. The performance of doublelayer capacitors is highly dependent on the nature of the electrolyte system used. Many applications, including for electric and fuel cell vehicles, back-up diesel generators, wind generator pitch control back-up power systems, environmental and structural distributed sensors, and spacecraft avionics, can potentially benefit from the use of double-layer capacitors with lower equivalent series resistances (ESRs) over wider temperature limits. Higher ESRs result in decreased power output, which is a particular problem at lower temperatures. Commercially available cells are typically rated for operation down to only 40 C. Previous briefs [for example, Low Temperature Supercapacitors (NPO-44386), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), p. 32, and Supercapacitor Electrolyte Solvents With Liquid Range Below 80 C (NPO-44855), NASA Tech Briefs, Vol. 34, No. 1 (January 2010), p. 44] discussed the use of electrolytes that employed low-melting-point co-solvents to depress the freezing point of traditional acetonitrile-based electrolytes. Using these modified electrolyte formulations can extend the low-temperature operational limit of double-layer capacitors beyond that of commercially available cells. This previous work has shown that although the measured capacitance is relatively insensitive to temperature, the ESR can rise rapidly at low temperatures, due to decreased electrolyte conductance within the pores of the high surface- area carbon electrodes. Most of these advanced electrolyte systems featured tetraethylammonium tetrafluoroborate (TEATFB) as the salt. More recent work at JPL indicates the use of the asymmetric quaternary ammonium salt triethylmethylammonium tetrafluoroborate (TEMATFB) or spiro-(l,l')-bipyrrolidium tetrafluoroborate (SBPBF4) in a 1:1 by volume solvent mixture of acetonitrile (AN) and methyl formate (MF) enables double-layer capacitor cells to operate well below -40 C with a relatively low ESR. Typically, a less than twofold increase in ESR is observed at -65 C relative to room-temperature values, when these modified electrolyte blends are used in prototype cells. Double-layer capacitor coin cells filled with these electrolytes have displayed the lowest measured ESR for an organic electrolyte to date at low temperature (based on a wide range of electrolyte screening studies at JPL). The cells featured high-surface-area (approximately equal to 2,500 m/g) carbon electrodes that were 0.50 mm thick and 1.6 cm in diameter, and coated with a thin layer of platinum to reduce cell resistance. A polyethylene separator was used to electrically isolate the electrodes.

  12. Numerical modelling of chloride propagation in the quaternary aquifer of the southern Upper Rhine Graben

    NASA Astrophysics Data System (ADS)

    Lang, U.; Gudera, T.; Elsass, P.; Wirsing, G.

    2005-09-01

    The deep groundwater in the quaternary gravel sequence of the southern Upper Rhine Graben locally contains high chloride concentrations near the river Rhine between Fessenheim (France) in the South and Breisach (Germany) in the North. This historical pollution is mainly due to past infiltration from the former brine storage basins of the French potash mines on the “Fessenheim Island” and—to a lesser extent—from the leaching of the salt dumps of the German potash mines in Buggingen and Heitersheim. The spreading of the salt plume was investigated by means of a groundwater model. The aim of the model was to understand the brine movement, the present distribution of chloride as defined by recent hydrochemical investigations, and to select locations for new reconnaissance boreholes. The geological structure was reproduced by a three layer model, which was calibrated for steady state flow conditions. The hydraulic conductivity of the first layer was determined by comparing measured and calculated heads in the model area. The vertical resolution was refined to simulate the density-dependent salt transport processes. The transport of the salt plumes was simulated over a 40-year period, starting at the beginning of brine storage in the 1950s. The relevant transport parameters have been estimated in a sensitivity analysis, where the simulated breakthrough curves of chloride concentration have been compared with the measured data. The results of the groundwater model indicate that brines containing approximately 1 million tons of chloride are still present at the bottom of the aquifer. These highly concentrated salt brines mix with fresh water from the upper part of the aquifer. This dispersive process leads to the formation of a plume of chloride-rich water extending downstream, where pumping wells for several local water supplies are located.

  13. Ion Transport and Local Structural Dynamics in Analogous Quaternary Ammonium and Phosphonium-Based Room Temperature Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Holt, Adam; Griffin, Philip; Tsunashima, Katsuhiko; Sangoro, Joshua; Sokolov, Alexei

    2015-03-01

    The ion transport and structural dynamics in a homologous pair of quaternary ammonium and phosphonium based room temperature ionic liquids (IL), [N2228][NTF2] and [P2228][NTF2], are investigated by depolarized dynamic light scattering and dielectric spectroscopy. The atomic identity of the cation center has a pronounced effect on both long-range ion conduction as well as structural relaxation in these quaternary ILs. The dc conductivity is significantly higher in the phosphonium based IL. While the increase in dc conductivity can be attributed to a lower glass transition temperature, i.e. faster structural dynamics, of the phosphonium IL, we also have found the atomic identity of the cation center strongly influences the local secondary relaxations. The secondary relaxations in the ammonium IL exhibit an unexpected non-Arrhenius temperature dependence -in stark contrast to its phosphonium counterpart. In addition to structural dynamics, changes in the secondary relaxations suggest the differences in dc conductivity may also be attributed to a change in counter-ion coordination and could lead to a difference in the mesoscale aggregation of alkyl moieties which is known to exist in these ILs. Therefore, subtle changes of inter-ionic interactions have a direct consequence on local, structural, and long-range dynamics in these analogous ILs.

  14. Accelerated OH(-) transport in activated carbon air cathode by modification of quaternary ammonium for microbial fuel cells.

    PubMed

    Wang, Xin; Feng, Cuijuan; Ding, Ning; Zhang, Qingrui; Li, Nan; Li, Xiaojing; Zhang, Yueyong; Zhou, Qixing

    2014-04-01

    Activated carbon (AC) is a promising catalyst for the air cathode of microbial fuel cells (MFCs) because of its high performance and low cost. To increase the performance of AC air cathodes, the acceleration of OH(-) transport is one of the most important methods, but it has not been widely investigated. Here we added quaternary ammonium to ACs by in situ anchoring of a quaternary ammonium/epoxide-reacting compound (QAE) or ex situ mixing with anion exchange resins in order to modify ACs from not only the external surface but also inside the pores. In 50 mM phosphate buffer solution (PBS), the in situ anchoring of QAE was a more effective way to increase the power. The highest power density of 2781 ± 36 mW/m(2), which is 10% higher than that of the control, was obtained using QAE-anchored AC cathodes. When the medium was switched to an unbuffered NaCl solution, the increase in maximum power density (885 ± 25 mW/m(2)) was in accordance with the anion exchange capacity (0.219 mmol/g). The highest power density of the anion exchange resin-mixed air cathode was 51% higher than that of the control, indicating that anion exchange is urgently needed in real wastewaters. Excess anchoring of QAE blocked both the mesopores and micropores, causing the power output to be inhibited. PMID:24597673

  15. A Systematic Investigation of Quaternary Ammonium Ions as Asymmetric Phase Transfer Catalysts. Synthesis of Catalyst Libraries and Evaluation of Catalyst Activity

    PubMed Central

    Denmark, Scott E.; Gould, Nathan D.; Wolf, Larry M.

    2011-01-01

    Despite over three decades of research into asymmetric phase transfer catalysis (APTC), a fundamental understanding of the factors that affect the rate and stereoselectivity of this important process are still obscure. This paper describes the initial stages of a long-term program aimed at elucidating the physical organic foundations of APTC employing a chemoinformatic analysis of the alkylation of a protected glycine imine with a libraries of enantiomerically enriched quaternary ammonium ions. The synthesis of the quaternary ammonium ions follows a diversity oriented approach wherein the tandem inter[4+2]/intra[3+2] cycloaddition of nitroalkenes serves as the key transformation. A two part synthetic strategy comprised of: (1) preparation of enantioenriched scaffolds and (2) development of parallel synthesis procedures is described. The strategy allows for the facile introduction of four variable groups in the vicinity of a stereogenic quaternary ammonium ion. The quaternary ammonium ions exhibited a wide range of activity and to a lesser degree enantioselectivity. Catalyst activity and selectivity are rationalized in a qualitative way based on the effective positive potential of the ammonium ion. PMID:21446721

  16. Ammonium Sulfate Improves Detection of Hydrophilic Quaternary Ammonium Compounds through Decreased Ion Suppression in Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry.

    PubMed

    Sugiyama, Eiji; Masaki, Noritaka; Matsushita, Shoko; Setou, Mitsutoshi

    2015-11-17

    Hydrophilic quaternary ammonium compounds (QACs) include derivatives of carnitine (Car) or choline, which are known to have essential bioactivities. Here we developed a technique for improving the detection of hydrophilic QACs using ammonium sulfate (AS) in matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). In MALDI mass spectrometry for brain homogenates, the addition of AS greatly increased the signal intensities of Car, acetylcarnitine (AcCar), and glycerophosphocholine (GPC) by approximately 300-, 700-, and 2500-fold. The marked improvement required a higher AS concentration than that needed for suppressing the potassium adduction on phosphatidylcholine and 2,5-dihydroxybenzoic acid. Adding AS also increased the signal intensities of Car, AcCar, and GPC by approximately 10-, 20-, and 40-fold in MALDI-IMS. Consequently, the distributions of five hydrophilic QACs (Car, AcCar, GPC, choline, and phosphocholine) were simultaneously visualized by this technique. The distinct mechanism from other techniques such as improved matrix application, derivatization, or postionization suggests the great potential of AS addition to achieve higher sensitivity of MALDI-IMS for various analytes. PMID:26492538

  17. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Wound dressing with poly (diallyl dimethyl... DEVICES Surgical Devices § 878.4015 Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification. A wound dressing with pDADMAC additive is intended for use as a...

  18. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Wound dressing with poly (diallyl dimethyl... DEVICES Surgical Devices § 878.4015 Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification. A wound dressing with pDADMAC additive is intended for use as a...

  19. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Wound dressing with poly (diallyl dimethyl... DEVICES Surgical Devices § 878.4015 Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification. A wound dressing with pDADMAC additive is intended for use as a...

  20. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Wound dressing with poly (diallyl dimethyl... DEVICES Surgical Devices § 878.4015 Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification. A wound dressing with pDADMAC additive is intended for use as a...

  1. 21 CFR 878.4015 - Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Wound dressing with poly (diallyl dimethyl... DEVICES Surgical Devices § 878.4015 Wound dressing with poly (diallyl dimethyl ammonium chloride) (pDADMAC) additive. (a) Identification. A wound dressing with pDADMAC additive is intended for use as a...

  2. Determination of the Optimum Conditions for Leaching of Zinc Cathode Melting Furnace Slag in Ammonium Chloride Media

    NASA Astrophysics Data System (ADS)

    Behnajady, Bahram; Babaeidehkordi, Amin; Moghaddam, Javad

    2014-04-01

    This research is part of a continuing effort to leach zinc from zinc cathode melting furnace slags (ZCMFSs) to produce zinc oxide. The slag with an assay of 68.05 pct Zn was used in ammonium chloride leaching for zinc extraction. In this paper, the effects of influential factors on extraction efficiency of Zn from a ZCMFS were investigated. The Taguchi's method based on orthogonal array (OA) design has been used to arrange the experimental runs in order to maximize zinc extraction from a slag. The softwares named Excel and Design-Expert 7 have been used to design experiments and subsequent analysis. OA L 25 (55) consisting of five parameters, each with five levels, was employed to evaluate the effects of reaction time ( t = 10, 30, 50, 70, 90 minutes), reaction temperature [ T = 313, 323, 333, 343, 353 (40, 50, 60, 70, 80) K (°C)], pulp density ( S/ L = 20, 40, 60, 80, 100 g/L), stirring speed ( R = 300, 400, 500, 600, 700 rpm), and ammonium chloride concentration ( C = 10, 15, 20, 25, 30 pctwt), on zinc extraction percent. Statistical analysis, ANOVA, was also employed to determine the relationship between experimental conditions and yield levels. The results showed that the significant parameters affecting leaching of slag were ammonium chloride concentration and pulp density, and increasing pulp density reduced leaching efficiency of zinc. However, increasing ammonium chloride concentration promoted the extraction of zinc. The optimum conditions for this study were found to be t 4: 70 minutes, T 5: 353 K (80 °C), ( S/ L)2: 40 g/L, R 3: 500 rpm, and C 4: 25 pctwt. Under these conditions, the dissolution percentage of Zn in ammonium chloride media was 94.61 pct.

  3. A water-soluble pH fluorescence probe based on quaternary ammonium salt for bioanalytical applications.

    PubMed

    Zhao, Xuan-Xuan; Ge, Di; Dai, Xi; Wu, Wen-Li; Miao, Jun-Ying; Zhao, Bao-Xiang

    2015-12-01

    A novel fluorescence probe Rhodamine-Ethanediamine-Iodomethane (REI) was successfully prepared to serve as an efficient sensing platform for H(+) with fully reversibility mainly between the pH 4.2 and 7.2 in simple buffer solution. The introduction of quaternary ammonium salt with positive charge can not only manage to increase the solubility and sensitivity of probe REI, but also avoid the "alkalizing effect" due to charge-induced effect compared to the reference probe Rhodamine-Ethanediamine (RE). In particular, probe REI was well used for monitoring the weak acid pH fluctuations in lysosome of the live HeLa cells due to its excellent biological properties, including low cytotoxicity, high selectivity, good sensitivity and membrane permeability. PMID:26142177

  4. Synthesis, in vitro, and in vivo evaluation of novel functionalized quaternary ammonium curcuminoids as potential anti-cancer agents.

    PubMed

    Solano, Lucas N; Nelson, Grady L; Ronayne, Conor T; Lueth, Erica A; Foxley, Melissa A; Jonnalagadda, Sravan K; Gurrapu, Shirisha; Mereddy, Venkatram R

    2015-12-15

    Novel functionalized quaternary ammonium curcuminoids have been synthesized from piperazinyl curcuminoids and Baylis-Hillman reaction derived allyl bromides. These molecules are found to be highly water soluble with increased cytotoxicity compared to native curcumin against three cancer cell lines MIAPaCa-2, MDA-MB-231, and 4T1. Preliminary in vivo toxicity evaluation of a representative curcuminoid 5a in healthy mice indicates that this molecule is well tolerated based on normal body weight gains compared to control group. Furthermore, the efficacy of 5a has been tested in a pancreatic cancer xenograft model of MIAPaCa-2 and has been found to exhibit good tumor growth inhibition as a single agent and also in combination with clinical pancreatic cancer drug gemcitabine. PMID:26561365

  5. Quantitative structure-activity relationship (QSAR) study of toxicity of quaternary ammonium compounds on Chlorella pyrenoidosa and Scenedesmus quadricauda.

    PubMed

    Jing, Guohua; Zhou, Zuoming; Zhuo, Jing

    2012-01-01

    The acute toxicity of 13 quaternary ammonium compounds (QACs) to Chlorella pyrenoidosa and Scenedesmus quadricauda was investigated in the present study. Significant inhibition on algae biomass was observed and 96 h EC(50)-value of 13 QACs was tested. Sixteen physicochemical and quantum chemical parameters of the QACs were calculated using the semi-empirical MOPAC AMI method. The multiple linear regression (MLR) was employed to derive the quantitative structure-activity relationship (QSAR) models, by which the calculated parameters were correlated to the toxicity of QACs on the two green algaes. Results showed that the alkyl chain lengths (CL) and total connectivity (T(Con)) were the main descriptors in governing the log (1/EC(50)) values of the QACs in the two QSAR models. The two models had high predictive ability and stability, and two parameters were proved to have the general applicability in QSAR study of QACs congeners. PMID:22014469

  6. A divalent quaternary alkyl ammonium salt as the electrolyte for high-energy electric double-layer capacitors

    NASA Astrophysics Data System (ADS)

    Zheng, Cheng; Yoshio, Masaki; Qi, Li; Wang, Hongyu

    2012-12-01

    A divalent electrolyte salt based on 1,1,4,4-tetramethyl piperazine has been synthesized and applied in electric double-layer capacitors (EDLCs). Traits of the divalent salts have been accessed as well as monovalent quaternary alkyl ammonium salts by the means of galvanostatic charge-discharge tests and ionic conductivity measurements. Compared with monovalent salts, the divalent salts do enlarge the charge storage ability of EDLCs remarkably. However, highly concentrated charge density on the divalent cation has a strong interaction with the organic solvent of propylene carbonate. The adverse effect of this heavy solvation on the performance of EDLCs has been investigated. Moreover, the influence of pore size distribution on the storage ability of these cations at the porous carbon electrode has been addressed.

  7. A Systematic Investigation of Quaternary Ammonium Ions as Asymmetric Phase Transfer Catalysts. Application of Quantitative Structure Activity/Selectivity Relationships

    PubMed Central

    Denmark, Scott E.; Gould, Nathan D.; Wolf, Larry M.

    2011-01-01

    While the synthetic utility of asymmetric phase transfer catalysis continues to expand, the number of proven catalyst types and design criteria remains limited. At the origin of this scarcity is a lack in understanding of how catalyst structural features affect the rate and enantioselectivity of phase transfer catalyzed reactions. Described in this paper is the development of quantitative structure-activity relationships (QSAR) and -selectivity relationships (QSSR) for the alkylation of a protected glycine imine with libraries of quaternary ammonium ion catalysts. Catalyst descriptors including ammonium ion accessibility, interfacial adsorption affinity, and partition coefficient were found to correlate meaningfully with catalyst activity. The physical nature of the descriptors was rationalized through differing contributions of the interfacial and extraction mechanisms to the reaction under study. The variation in the observed enantioselectivity was rationalized employing a comparative molecular field analysis (CoMFA) using both the steric and electrostatic fields of the catalysts. A qualitative analysis of the developed model reveals preferred regions for catalyst binding to afford both configurations of the alkylated product. PMID:21446723

  8. O-2'-hydroxypropyltrimethyl ammonium chloride chitosan nanoparticles for the delivery of live Newcastle disease vaccine.

    PubMed

    Dai, Chunxiao; Kang, Hong; Yang, Wanqiu; Sun, Jinyan; Liu, Chunlong; Cheng, Guogang; Rong, Guangyu; Wang, Xiaohua; Wang, Xin; Jin, Zheng; Zhao, Kai

    2015-10-01

    A novel complex chitosan derivative, O-2'-hydroxypropyltrimethyl ammonium chloride chitosan (O-2'-HACC), was synthesized and used to make nanoparticles as a delivery vehicle for live attenuated Newcastle disease vaccine. We found that O-2'-HACC had high antimicrobial activity, low toxicity, and a high safety level. Newcastle disease virus (NDV) was then encapsulated in the O-2'-HACC nanoparticles (NDV/La Sota-O-2'-HACC-NPs) by the ionic crosslinking method, and the properties of the resulting nanoparticles were determined by transmission electron microscopy, Zeta potential analysis, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and X-ray diffraction. NDV/La Sota-O-2'-HACC-NPs had regular spherical morphologies and high stability, with an encapsulation efficiency of 95.68 ± 2.2% and a loading capacity of 58.75 ± 4.03%. An in vitro release assay indicated that release of NDV from NDV/La Sota-O-2'-HACC-NPs occurred slowly. Specific pathogen-free chickens immunized with NDV/La Sota-O-2'-HACC-NPs intranasally had much stronger cellular, humoral and mucosal immune responses than did those immunized intramuscularly or with live attenuated Newcastle disease vaccine. NDV/La Sota-O-2'-HACC-NPs are a novel drug delivery carrier with immense potential in medical applications. PMID:26076628

  9. THE EFFECTS OF PARATHORMONE AND AMMONIUM CHLORIDE ON THE BONES OF RABBITS

    PubMed Central

    Jaffe, Henry L.; Bodansky, Aaron; Blair, John E.

    1932-01-01

    1. A very large single dose of parathormone produced rapid and extensive decalcification of the bones of a young rabbit. 2. Gradually increased doses of parathormone failed to produce significant changes in the bones of young and fully grown adult rabbits. 3. Ammonium chloride, administered by stomach tube was without effect on the bones, when given to rabbits treated with parathormone or to otherwise untreated rabbits. 4. Calcium lactate did not promote the appearance of signs of parathormone overdosage in rabbits during treatment, nor were metastatic calcifications observed in the soft tissues after termination of the experiment. 5. The rabbit is relatively very resistant to the decalcifying effects of gradually increased repeated doses of parathormone, and therefore is not satisfactory material for experimental studies of bone changes of chronic hyperparathyroidism. 6. The appearance of actively transforming bones of a young growing rabbit, particularly at the sites of rapid growth, is not to be confused with the more severe fibrous processes produced by parathormone in guinea pigs, dogs and rats. PMID:19870023

  10. Dental plaque microcosm response to bonding agents containing quaternary ammonium methacrylates with different chain lengths and charge densities

    PubMed Central

    Zhou, Han; Li, Fang; Weir, Michael D.; Xu, Hockin H.K.

    2013-01-01

    Objectives Antibacterial bonding agents are promising to combat bacteria and caries at tooth-restoration margins. The objectives of this study were to incorporate new quaternary ammonium methacrylates (QAMs) to bonding agent and determine the effects of alkyl chain length (CL) and quaternary amine charge density on dental plaque microcosm bacteria response for the first time. Methods Six QAMs were synthesized with CL = 3, 6, 9, 12, 16, 18. Each QAM was incorporated into Scotchbond Multi-purpose (SBMP). To determine the charge density effect, dimethylaminododecyl methacrylate (DMAHDM, CL = 16) was mixed into SBMP at mass fraction = 0%, 2.5%, 5%, 7.5%, 10%. Charge density was measured using a fluorescein dye method. Dental plaque microcosm using saliva from ten donors was tested. Bacteria were inoculated on resins. Early-attachment was tested at 4 hours. Biofilm colony-forming units (CFU) were measured at 2 days. Results Incorporating QAMs into SBMP reduced bacteria early-attachment. Microcosm biofilm CFU for CL = 16 was 4 log lower than SBMP control. Charge density of bonding agent increased with DMAHDM content. Bacteria early-attachment decreased with increasing charge density. Biofilm CFU at 10% DMAHDM was reduced by 4 log. The killing effect was similarly-strong against total microorganisms, total streptococci, and mutans streptococci. Conclusions Increasing alkyl chain length and charge density of bonding agent was shown for the first time to decrease microcosm bacteria attachment and reduce biofilm CFU by 4 orders of magnitude. Novel antibacterial resins with tailored chain length and charge density are promising for wide applications in bonding, cements, sealants and composites to inhibit biofilms and caries. PMID:23948394

  11. Assay of 1-ammonium-3,5-dinitro-1,2,4-triazole and its determination in mixtures with ammonium nitrate. [Titrant - cetylpyridinium chloride

    SciTech Connect

    Selig, W.

    1981-07-01

    Work is in progress at this Laboratory on the detonation calorimetry of ammonium dinitrotriazole (ADNT) and mixtures of ADNT and ammonium nitrate (AN). Our analytical requirements were therefore, twofold: (1) the assay of ADNT, and (2) the determination of ADNT in admixture with AN. The first requirement was straightforward and was accomplished by nonaqueous titration of ADNT, either as an acid or as a base. The second requirement, however, proved more difficult. It was accomplished by using cetypyridinium chloride (CPC), a new titrant recently introduced at this Laboratory to determine the ADNT in the mixture. Various liquid-membrane electrodes such as the fluoroborate, perchlorate, and nitrate ion-selective electrodes (ISE's) may be used as endpoint sensors. We have found that the solid-state cyanide (or iodide) ISE also senses the endpoint of this titration, although considerably smaller endpoint breaks are obtained. Nevertheless, the mean values obtained using the fluoroborate and cyanide ISE's differed by only 0.09%. The method can also be used for the assay of some ammonium salts of other nitroheterocycles. It cannot differentiate, however, between the various compounds.

  12. Separation of aromatic carboxylic acids using quaternary ammonium salts on reversed-phase HPLC. 1. Separation behavior of aromatic carboxylic acids

    SciTech Connect

    Kawamura, K.; Okuwaki, A.; Verheyen, T.; Perry, G.J.

    2006-02-15

    In order to develop separation processes and analytical methods for aromatic carboxylic acids for the coal oxidation products, the separation behavior of aromatic carboxylic acids on a reversed-phase HPLC using eluent containing quaternary ammonium salt has been investigated. The retention mechanism of aromatic carboxylic acids was discussed on the basis of both ion-pair partition model and ion-exchange model. The retention behavior of aromatic carboxylic acids possessing one (or two) carboxylic acid group(s) followed the ion-pair partition model, where linear free energy relationship was observed between the capacity factor and the extraction equilibrium constants of benzoic acid and naphthalene carboxylic acid. Besides, the retention behavior followed ion-exchange model with increasing the number of carboxylic acids, where the capacity factor of benzene polycarboxylic acids is proportional to the association constants between aromatic acids and quaternary ammonium ions calculated on the basis of an electrostatic interaction model.

  13. Metal Complex Formation in Melts of Acetamide-Ammonium Nitrate-Water Mixtures, Part I. Cobalt(II) Chloride Complexes

    NASA Astrophysics Data System (ADS)

    Zsigrai, István J.; Gadžuri?, Slobodan B.; Matijevi?, Borko

    2005-03-01

    The complex formation between cobalt(II) and chloride ions in molten NH4NO3?2.61H2O, NH4NO3?CH3CONH2?1.61H2O and NH4NO3?2.61CH3CONH2 has been investigated. Absorption spectra of cobalt(II) chloride containing variable amounts of ammonium chloride were recorded at 45 to 60 °C. In the absence of chloride, the solutions show spectra typical for octahedral co-ordination of cobalt(II). Addition of chloride caused a shift of the absorption maximum toward lower energies and an increase of the molar absorption coefficient with increasing chloride concentration. The position of the absorption maximum and the intensity of the absorption indicate tetrahedral or severely distorted octahedral co-ordination. The stability constants for [Co(NO3)4]2-, [Co(NO3)2Cl2]2- and [CoCl4]2- complex formation in NH4NO3?2.61CH3CONH2 are reported.

  14. Preparation and characterisation of anion exchangers with dihydroxy-containing alkyl substitutes in the quaternary ammonium functional groups.

    PubMed

    Zatirakha, A V; Smolenkov, A D; Pirogov, A V; Nesterenko, P N; Shpigun, O A

    2014-01-01

    Novel poly(styrene-divinylbenzene) (PS-DVB) based anion exchangers having one and two (2,3-dihydroxypropyl) substitutes in the quaternary ammonium functional groups are prepared and characterised by ion chromatography (IC). The introduction of bulky and hydrophilic substitutes to the anion-exchange groups allows the elimination of non-ionic interactions between the polarisable anions and the aromatic rings from the matrix and the improvement of separation selectivity as compared with the traditional trimethylammonium (TMA) functionalised ion exchangers. The synthesis of the ion exchangers includes acylation of PS-DVB particles with acetic anhydride followed by reductive amination either with methylamine hydrochloride or dimethylamine and further alkylation with oxiranes under varied conditions. The ion exchange selectivity and separation efficiency of nine adsorbents having different structure of bonded groups, ion exchange capacity (9-98?equiv.g(-1)) or particle size is studied for model mixture of inorganic anions (F(-), Cl(-), NO2(-), Br(-), NO3(-), HPO4(2-) and SO4(2-)) using carbonate and hydroxide eluents. The adsorbents with more hydrophilic substitutes provided superior columns efficiencies and better peak symmetry as compared with analogues having hydrophobic functional groups. The calculated values of column efficiencies for polarisable NO3(-) and HPO4(2-) are 18,500 and 29,000N/m, respectively, for anion-exchanger, having N-methyl-N',N?-di-(2,3-dihydroxypropyl)ammonium groups which is significantly higher than 1800 and 12,000N/m obtained for these anions with anion exchanger bearing TMA functional groups. PMID:24309716

  15. Ammonium Chloride Ingestion Attenuates Exercise-Induced mRNA Levels in Human Muscle

    PubMed Central

    Mündel, Toby; Pilegaard, Henriette; Hawke, Emma; Leikis, Murray; Lopez-Villalobos, Nicolas; Oliveira, Rodrigo S. F.; Bishop, David J.

    2015-01-01

    Minimizing the decrease in intracellular pH during high-intensity exercise training promotes greater improvements in mitochondrial respiration. This raises the intriguing hypothesis that pH may affect the exercise-induced transcription of genes that regulate mitochondrial biogenesis. Eight males performed 10x2-min cycle intervals at 80% V?O2peak intensity on two occasions separated by ~2 weeks. Participants ingested either ammonium chloride (ACID) or calcium carbonate (PLA) the day before and on the day of the exercise trial in a randomized, counterbalanced order, using a crossover design. Biopsies were taken from the vastus lateralis muscle before and after exercise. The mRNA level of peroxisome proliferator-activated receptor co-activator 1? (PGC-1?), citrate synthase, cytochome c and FOXO1 was elevated at rest following ACID (P<0.05). During the PLA condition, the mRNA content of mitochondrial- and glucose-regulating proteins was elevated immediately following exercise (P<0.05). In the early phase (0–2 h) of post-exercise recovery during ACID, PGC-1?, citrate synthase, cytochome C, FOXO1, GLUT4, and HKII mRNA levels were not different from resting levels (P>0.05); the difference in PGC-1? mRNA content 2 h post-exercise between ACID and PLA was not significant (P = 0.08). Thus, metabolic acidosis abolished the early post-exercise increase of PGC-1? mRNA and the mRNA of downstream mitochondrial and glucose-regulating proteins. These findings indicate that metabolic acidosis may affect mitochondrial biogenesis, with divergent responses in resting and post-exercise skeletal muscle. PMID:26656911

  16. Ammonium Chloride Ingestion Attenuates Exercise-Induced mRNA Levels in Human Muscle.

    PubMed

    Edge, Johann; Mündel, Toby; Pilegaard, Henriette; Hawke, Emma; Leikis, Murray; Lopez-Villalobos, Nicolas; Oliveira, Rodrigo S F; Bishop, David J

    2015-01-01

    Minimizing the decrease in intracellular pH during high-intensity exercise training promotes greater improvements in mitochondrial respiration. This raises the intriguing hypothesis that pH may affect the exercise-induced transcription of genes that regulate mitochondrial biogenesis. Eight males performed 10x2-min cycle intervals at 80% [Formula: see text] intensity on two occasions separated by ~2 weeks. Participants ingested either ammonium chloride (ACID) or calcium carbonate (PLA) the day before and on the day of the exercise trial in a randomized, counterbalanced order, using a crossover design. Biopsies were taken from the vastus lateralis muscle before and after exercise. The mRNA level of peroxisome proliferator-activated receptor co-activator 1? (PGC-1?), citrate synthase, cytochome c and FOXO1 was elevated at rest following ACID (P<0.05). During the PLA condition, the mRNA content of mitochondrial- and glucose-regulating proteins was elevated immediately following exercise (P<0.05). In the early phase (0-2 h) of post-exercise recovery during ACID, PGC-1?, citrate synthase, cytochome C, FOXO1, GLUT4, and HKII mRNA levels were not different from resting levels (P>0.05); the difference in PGC-1? mRNA content 2 h post-exercise between ACID and PLA was not significant (P = 0.08). Thus, metabolic acidosis abolished the early post-exercise increase of PGC-1? mRNA and the mRNA of downstream mitochondrial and glucose-regulating proteins. These findings indicate that metabolic acidosis may affect mitochondrial biogenesis, with divergent responses in resting and post-exercise skeletal muscle. PMID:26656911

  17. Environmental assessment of an alkyl dimethyl benyzl ammonium chloride (ADBAC) based mollusicide using laboratory tests

    SciTech Connect

    Dobbs, M.G.; Cherry, D.S.; Scott, J.C.; Petrille, J.C.

    1995-06-01

    A series of acute and chronic toxicity tests were conducted to estimate the potential environmental impact of n-alkyl dimethyl benzyl ammonium chloride (ADBAC) when used to control zebra mussels and other types of macrofouling organism in industrial cooling systems. The ADBAC-based molluscicide was tested as pure product and often detoxification with bentonite clay. Six flow-through acute tests were conducted to estimate the toxicity of ADBAC. In addition three chronic toxicity tests using Pimephales promelas, Daphnia magna and Selenastrum capricornutum were carried out to evaluate the efficacy of complexing the ADBAC-based molluscicide with a bentonite clay as a detoxification strategy. A 29-day CO{sub 2} Production test was also conducted to evaluate the biodegradability of the molluscicide. Of the six species tested in acute flow-through experiments, D. magna (LC{sub 50} = 0.02 mg ADBAC/L) was the most sensitive species followed by Mysidopsis bahia (LC{sub 50} = 0.08 mg ADBAC/L), Menidia beryllina (LC{sub 50} = 0.88 mg ADBAC/L), P. promelas (LC{sub 50} = 0.36 mg ADBAC/L), Cyprinodon variegatus (LC{sub 50} = 0.88 mg ADBAC/L), and Oncorhynchus mykiss (LC{sub 50} = 1.01 mg ADBAC/L). In the detoxification studies the three test species were exposed to treatment levels of: 0:0, 2.5:0, 2.5:25, 2.5:37.5, 2.5:50, 2.5:75, and 0:75 as mg/L ADBAC:clay. Bentonite clay was found to be an effective detoxification agent for this molluscicide at all treatment levels, except for the 2.5:25 treatment. In addition, a biodegradation study showed that the ADBAC-based molluscicide was readily biodegradable by unacclimated activated sludge microorganisms releasing 65.9% of the theoretical possible CO{sub 2} after 29 days.

  18. Selective binding affinity between quaternary ammonium cations and water-soluble calix[4]resorcinarene.

    PubMed

    Hong, Meiling; Zhang, Ying-Ming; Liu, Yu

    2015-02-01

    An amphiphilic calix[4]resorcinarene bearing four hydrophilic sulfonate sites at the upper rim and four hydrophobic n-pentyl chains at the lower rim (SR4A5) was synthesized by sulfonation of tetramethoxyresorcinarene. The molecular binding behaviors of SR4A5 with different types of organic cations, i.e., singly and doubly charged aliphatic ammonium salts and singly and doubly charged ?-aromatic ammonium salts, were comprehensively investigated by means of (1)H NMR, fluorescence, and UV/vis spectroscopic titration experiments. The competitive binding titrations demonstrate that, superior to the reported p-sulfonatocalix[4]arene systems, the stability constants upon association with SR4A5 can reach up to 10(6) M(-1) order of magnitude in water, ultimately leading to better binding affinity and molecular selectivity toward dicationic guests. Significantly, UV/vis spectroscopic experiments further revealed that the specific binding behaviors of SR4A5 with bispyridinium guests can be attributed to the charge transfer interaction between electron-rich and electron-deficient aromatics upon host-guest complexation. These obtained results provide an effective strategy to realize the highly selective molecular recognition process with multiply charged macrocyclic receptors and will definitely promote the development of the field of water-soluble resorcinarene-based supramolecular assemblies. PMID:25584396

  19. Separation of aromatic carboxylic acids using quaternary ammonium salts on reversed-phase HPLC. 2. Application for the analysis of Loy Yang coal oxidation products

    SciTech Connect

    Kawamura, K.; Okuwaki, A.; Verheyen, T.V.; Perry, G.J.

    2006-07-01

    In order to develop separation processes and analytical methods for aromatic carboxylic acids for the coal oxidation products, the separation behavior of aromatic carboxylic acids on a reversed-phase HPLC using eluent containing quaternary ammonium salt was optimized using the solvent gradient method. This method was applied for the analysis of Loy Yang coal oxidation products. It was confirmed that the analytical data using this method were consistent with those determined using gas chromatography.

  20. UV-Vis spectrophotometric studies of self-oxidation/dissociation of quaternary ammonium permanganates (QAP) - impact of solvent polarity

    NASA Astrophysics Data System (ADS)

    Bank, Suraj Prakash; Guru, Partha Sarathi; Dash, Sukalyan

    2015-05-01

    Self-oxidation/dissociation of some quaternary ammonium permanganates (QAPs), such as cetyltrimethylammonium permanganate (CTAP) and tetrabutylammonium permanganate (TBAP), have been studied spectrophotometrically in six different organic solvent media of different polarities wherein the compounds show good solubility and stability. The optical densities of the substrates at zero time (ODo) and first-order rate constants of dissociation (k1) have been determined from their successive scanning for 40 min. At comparable experimental conditions, absorption capabilities of the substrates are compared from the ODo values in various organic media; the stability of the solutions is compared from the successive scan spectra in those media. The ODo values and the k1 values have been plotted against some solvent parameters to understand their effects on the absorbance and reactivity of the QAPs. These data are also subjected to multiple regression analysis to explain the influence of various solvent parameters on the ion-pairing properties of the substrates, thus elucidating their effects on the process of self-oxidation/dissociation of the substrates.

  1. Retention behavior of long chain quaternary ammonium homologues and related nitroso-alkymethylamines

    USGS Publications Warehouse

    Abidi, S.L.

    1985-01-01

    Several chromatographic methods have been utilized to study the retentionbehavior of a homologous series of n-alkylbenzyldimethylammonium chlorides (ABDAC) and the corresponding nitroso-n-alkylmethylamines (NAMA). Linear correlation of the logarithmic capacity factor (k') with the number of carbons in the alkyl chain provides useful information on both gas chromatographic (GC) and high-performance liquid chromatographich (HPLC) retention parameters of unknown components. Under all conditions empolyed, GC methodology has proved effective in achieving complete resolution of the homologous mixture of NMA despite its obvious inadequacy in the separation of E-Z configurational isomers. Conversely, normal-phase HPLC on silica demonstrates that the selectivity (a) value for an E-Z pair is much higher than that for an adjacent homologous pair. In the reversed-phase HPLC study, three different silica-based column systems were examined under various mobile phase conditions. The extent of variation in k' was found to be a function of the organic modifier, counter-ion concentration, eluent pH, nature of counter-ion, and the polarity and type of stationary phase. The k'—[NaClO4] profiles showed similar trends between the ABDAC and the NAMA series, supporting the dipolar electronic structures of the latter compounds. Mobile phase and stationary phase effects on component separation are described. The methodology presented establishes the utility of HPLC separation techniques as versatile analytical tools for practical application.

  2. On-chip cell lysis by antibacterial non-leaching reusable quaternary ammonium monolithic column.

    PubMed

    Aly Saad Aly, Mohamed; Gauthier, Mario; Yeow, John

    2016-02-01

    Reusable antibacterial non-leaching monolithic columns polymerized in microfluidic channels designed for on-chip cell lysis applications were obtained by the photoinitiated free radical copolymerization of diallyldimethylammonium chloride (DADMAC) and ethylene glycol diacrylate (EGDA) in the presence of a porogenic solvent. The microfluidic channels were fabricated in cross-linked poly(methyl methacrylate) (X-PMMA) substrates by laser micromachining. The monolithic columns have the ability to inhibit the growth of, kill and efficiently lyse Gram-positive Micrococcus luteus (Schroeter) (ATCC 4698) and Kocuria rosea (ATCC 186), and Gram-negative bacteria Pseudomonas putida (ATCC 12633) and Escherichia coli (ATCC 35218) by mechanically shearing the bacterial membrane when forcing the cells to pass through the narrow pores of the monolithic column, and simultaneously disintegrating the cell membrane by physical contact with the antibacterial surface of the column. Cell lysis was confirmed by off-chip PCR without the need for further purification. The influence of the cross-linking monomer on bacterial growth inhibition, leaching, lysis efficiency of the monolithic column and its mechanical stability within the microfluidic channel were investigated and analyzed for three different cross-linking monomers: ethylene glycol dimethacrylate (EGDA), ethylene glycol dimethacrylate (EGDMA) and 1,6-hexanediol dimethacrylate (1,6-HDDMA). Furthermore, the bonding efficiency of two X-PMMA substrates with different cross-linking levels was studied. The monolithic columns were shown to be stable, non-leaching, and reusable for over 30 lysis cycles without significant performance degradation or DNA carryover when they were back-flushed between lysis cycles. PMID:26671610

  3. Survival of Adhering Staphylococci during Exposure to a Quaternary Ammonium Compound Evaluated by Using Atomic Force Microscopy Imaging?

    PubMed Central

    Crismaru, Mihaela; Asri, Lia A. T. W.; Loontjens, Ton J. A.; Krom, Bastiaan P.; de Vries, Joop; van der Mei, Henny C.; Busscher, Henk J.

    2011-01-01

    Effects of a quaternary ammonium compound (QAC) on the survival of adhering staphylococci on a surface were investigated using atomic force microscopy (AFM). Four strains with different minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) for the QAC were exposed to three different concentrations of the QAC in potassium phosphate buffer (0.5×, 1×, and 2× MBC) while adhering to glass. Adhering staphylococci were repeatedly imaged with AFM in the contact mode, and the cell surface was found to wrinkle upon progressive exposure to the QAC until bacteria disappeared from the substratum. Higher concentrations of QAC yielded faster wrinkling and the disappearance of bacteria during imaging. Two slime-producing staphylococcal strains survived longer on the surface than two non-slime-producing strains despite similar MICs and MBCs. All staphylococci adhering in unscanned areas remained adhering during exposure to QAC. Since MICs and MBCs did not relate to bacterial cell surface hydrophobicities and zeta potentials, survival on the surface is probably not determined by the direct interaction of QAC molecules with the cell surface. Instead, it is suggested that the pressure of the AFM tip assists the incorporation of QAC molecules in the membrane and enhances their bactericidal efficacy. In addition, the prolonged survival under pressure from slime-producing strains on a surface may point to a new protective role of slime as a stress absorber, impeding the incorporation of QAC molecules. The addition of Ca2+ ions to a QAC solution yielded longer survival of intact, adhering staphylococci, suggesting that Ca2+ ions can impede the exchange of membrane Ca2+ ions required for QAC incorporation. PMID:21876063

  4. Review and phylogenetic analysis of qac genes that reduce susceptibility to quaternary ammonium compounds in Staphylococcus species

    PubMed Central

    Ussery, David; Nielsen, Lene N.; Ingmer, Hanne

    2015-01-01

    The qac genes of Staphylococcus species encode multidrug efflux pumps: membrane proteins that export toxic molecules and thus increase tolerance to a variety of compounds such as disinfecting agents, including quaternary ammonium compounds (for which they are named), intercalating dyes and some antibiotics. In Stapylococcus species, six different plasmid-encoded Qac efflux pumps have been described, and they belong to two major protein families. QacA and QacB are members of the Major Facilitator Superfamily, while QacC, QacG, QacH, and QacJ all belong to the Small Multidrug Resistance (SMR) family. Not all SMR proteins are called Qac and the reverse is also true, which has caused confusion in the literature and in gene annotations. The discovery of qac genes and their presence in various staphylococcal populations is briefly reviewed. A sequence comparison revealed that some of the PCR primers described in the literature for qac detection may miss particular qac genes due to lack of DNA conservation. Despite their resemblance in substrate specificity, the Qac proteins belonging to the two protein families have little in common. QacA and QacB are highly conserved in Staphylococcus species, while qacA was also detected in Enterococcus faecalis, suggesting that these plasmid-born genes have spread across bacterial genera. Nevertheless, these qacA and qacB genes are quite dissimilar to their closest homologues in other organisms. In contrast, SMR-type Qac proteins display considerable sequence variation, despite their short length, even within the Staphylococcus genus. Phylogenetic analysis of these genes identified similarity to a large number of other SMR members, found in staphylococci as well as in other genera. A number of phylogenetic trees of SMR Qac proteins are presented here, starting with genes present in S. aureus and S. epidermidis, and extending this to related genes found in other species of this genus, and finally to genes found in other genera. PMID:25883793

  5. Synergistic antimicrobial activity based on the combined use of a gemini-quaternary ammonium compound and ultraviolet-A light.

    PubMed

    Shirai, Akihiro; Aihara, Mutsumi; Takahashi, Akira; Maseda, Hideaki; Omasa, Takeshi

    2014-01-01

    This study examined the utility of synergistic disinfection employing a gemini-quaternary ammonium salt (a gemini-QUAT, namely 3,3'-(2,7-dioxaoctane)bis(1-decylpyridinium bromide)), as an organic biocide in combination with irradiation by an ultraviolet-A (UV-A) light-emitting diode (LED) with a peak wavelength of 365nm. The combined system represents a novel disinfection method utilizing facilitated in situ oxidation depending on overproduction of reactive oxygen species (ROS) triggered by the initial action of the gemini-QUAT on the bacterial membrane. We demonstrate that this combination decreased the viability of pathogenic bacteria in a significant and rapid manner, and depended on doses of the gemini-QUAT and the fluence: the viability of Escherichia coli was reduced by greater than 5.0-logs by the combination procedure, but the decrease in viability was only 2.3-logs for exposure to UV at the same fluence dose in the absence of the gemini-QUAT. Adding catalase as a radical scavenger decreased bacterial inactivation by the combined disinfection procedure. Flow cytometric analysis indicated superoxide and hydrogen peroxide overproduction within cells treated with the combined disinfection procedure. The excessive superoxide, detected only in the combined system, appeared to be generated by the action of the gemini-QUAT at the bacterial membrane, leading to excessive and rapid generation of ROS in the system. Our data strongly suggested that this ROS promoted bacterial membrane peroxidation during initial treatment by the combination method, resulting in increased oxidative modification of DNA. These oxidative reactions may play an important role in the efficacy of this disinfection procedure. PMID:24362318

  6. Antibacterial effects of quaternary bis-phosphonium and ammonium salts of pyridoxine on Staphylococcus aureus cells: A single base hitting two distinct targets?

    PubMed

    Nikitina, Elena V; Zeldi, Marina I; Pugachev, Mikhail V; Sapozhnikov, Sergey V; Shtyrlin, Nikita V; Kuznetsova, Svetlana V; Evtygin, Vladimir E; Bogachev, Mikhail I; Kayumov, Airat R; Shtyrlin, Yurii G

    2016-01-01

    We studied the effects of quaternary bis-phosphonium and bis-ammonium salts of pyridoxine with lipophilic substituents on the survival and morphology of Staphylococcus aureus cells. We found that, while originating from the same base, they exhibit considerably different antimicrobial mechanisms. In the presence of Ca(2+) ions the MIC and MBC values of ammonium salt increased 100-fold, suggesting that Ca(2+) ions can successfully impede the membrane Ca(2+) ions exchange required for ammonium salt incorporation. In contrast, in the presence of quaternary phosphonium salt, the artificial capsular-like material was formed around the cells and the filamentous and chain-like growth of the cells was observed suggesting the disruption of the cell division mechanisms. Altogether, both pyridoxine derivatives successfully inhibited the growth of gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis) and Escherichia coli considerably, while demonstrated nearly no effect against Klebsiella pneumoniae and Pseudomonas aeruginosa. We suggest that due to their effects on distinct and likely complementary targets the derivatives of pyridoxine represent potentially perspective antibacterials with complicated adaptation and thus with lower risk of drug resistance development. PMID:26712620

  7. Preparation and modification of N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride nanoparticle as a protein carrier.

    PubMed

    Xu, Yongmei; Du, Yumin; Huang, Ronghua; Gao, Leping

    2003-12-01

    N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) is water-soluble derivative of chitosan (CS), synthesized by the reaction between glycidyl-trimethyl-ammonium chloride and CS. HTCC nanoparticles have been formed based on ionic gelation process of HTCC and sodium tripolyphosphate (TPP). Bovine serum albumin (BSA), as a model protein drug, was incorporated into the HTCC nanoparticles. HTCC nanoparticles were 110-180 nm in size, and their encapsulation efficiency was up to 90%. In vitro release studies showed a burst effect and a slow and continuous release followed. Encapsulation efficiency was obviously increased with increase of initial BSA concentration. Increasing TPP concentration from 0.5 to 0.7 mg/ml promoted encapsulation efficiency from 46.7% to 90%, and delayed release. As for modified HTCC nanoparticles, adding polyethylene glycol (PEG) or sodium alginate obviously decreased the burst effect of BSA from 42% to 18%. Encapsulation efficiency was significantly reduced from 47.6% to 2% with increase of PEG from 1.0 to 20.0 mg/ml. Encapsulation efficiency was increased from 14.5% to 25.4% with increase of alginate from 0.3 to 1.0 mg/ml. PMID:14559015

  8. Radiation Stability of Benzyl Tributyl Ammonium Chloride Towards Technetium-99 Extraction

    SciTech Connect

    Jared Horkley; Audrey Roman; Keri Campbell; Ana Nunez; Amparo Espartero

    2013-02-01

    A closed nuclear fuel cycle combining new separation technologies along with generation III and generation IV reactors is a promising way to achieve a sustainable energy supply. But it is important to keep in mind that future recycling processes of used nuclear fuel (UNF) must minimize wastes, improve partitioning process, and integrate waste considerations into processes. New separation processes are being developed worldwide to complement the actual industrialized PUREX process which selectively separates U(VI) and Pu(IV) from the raffinate. As an example, low nitric acid concentration in the aqueous phase of a UREX based process will co-extract U(VI) and Tc(VII) by tri-n-butyl phosphate (TBP). Technetium (Tc-99) is recognized to be one of the most abundant, long-lived radiotoxic isotopes in UNF (half-life, t1/2 = 2.13 × 105 years), and as such, it is targeted in UNF separation strategies for isolation and encapsulation in solid waste forms for final disposal in a nuclear waste repository. Immobilization of Tc-99 by a durable solid waste form is a challenge, and its fate in new advanced technology processes is of importance. It is essential to be able to quantify and locate 1) its occurrence in any new developed flow sheets, 2) its chemical form in the individual phases of a process, 3) its potential quantitative transfer in any waste streams, and consequently, 4) its quantitative separation for either potential transmutation to Ru-100 or isolation and encapsulation in solid waste forms for ultimate disposal. Furthermore, as a result of an U(VI)-Tc(VII) co-extraction in a UREX-based process, Tc(VII) could be found in low level waste (LLW) streams. There is a need for the development of new extraction systems that would selectively extract Tc-99 from LLW streams and concentrate it for feed into high level waste (HLW) for either Tc-99 immobilization in metallic waste forms (Tc-Zr alloys), and/or borosilicate-based waste glass. Studies have been launched to investigate the suitability of new macrocompounds such as crown-ethers, aza-crown ethers, and resorcinarenes for the selective extraction of Tc-99 from nitric acid solutions. The selectivity of the ligand is important in evaluating potential separation processes and also the radiation stability of the molecule is essential for minimization of waste and radiolysis products. In this paper, we are reporting the extraction of TcO4- by benzyltributyl ammonium chloride (BTBA). Experimental efforts were focused on determining the best extraction conditions by varying the ligand’s matrix conditions and concentration, as well as varying the organic phase composition (i.e., diluent variation). Furthermore, the ligand has been investigated for radiation stability. The ?-irradiation was performed on the neat organic phases containing the ligand at different absorbed doses to a maximum of 200 kGy using external Co-60 source. Post-irradiation solvent extraction measurements will be discussed.

  9. 77 FR 47291 - Residues of Didecyl Dimethyl Ammonium Chloride; Exemption From the Requirement of a Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-08

    ..., 2007); 73 FR 37852 (July 2, 2008) this proposed ] seed treatment use adds essentially zero additional... September 7, 2011 (76 FR 55329) (FRL- 8886-7), EPA issued a notice pursuant to section 408(d)(3) of FFDCA... Quaternaries can be found at 73 FR 37852 (July 2, 2008). IV. Aggregate Exposures In examining...

  10. Effect of a Novel Quaternary Ammonium Methacrylate Polymer (QAMP) on Adhesion and Antibacterial Properties of Dental Adhesives

    PubMed Central

    Pupo, Yasmine M.; Farago, Paulo Vitor; Nadal, Jessica M.; Simão, Luzia C.; Esmerino, Luís Antônio; Gomes, Osnara M. M.; Gomes, João Carlos

    2014-01-01

    This study investigated the resin–dentin bond strength (?TBS), degree of conversion (DC), and antibacterial potential of an innovative adhesive system containing a quaternary ammonium methacrylate polymer (QAMP) using in situ and in vitro assays. Forty-two human third molars were flattened until the dentin was exposed and were randomly distributed into three groups of self-etching adhesive systems: Clearfil™ SE Bond containing 5% QAMP (experimental group), Clearfil™ Protect Bond (positive control) and Clearfil™ SE Bond (negative control). After light curing, three 1 mm-increments of composite resin were bonded to each dentin surface. A total of thirty of these bonded teeth (10 teeth per group) was sectioned to obtain stick-shaped specimens and tested under tensile stress immediately, and after 6 and 12 months of storage in distilled water. Twelve bonded teeth (4 teeth per group) were longitudinally sectioned in a mesio-to-distal direction to obtain resin-bonded dentin slabs. In situ DC was evaluated by micro-Raman spectroscopy. In vitro DC of thin films of each adhesive system was measured using Fourier transform infrared spectroscopy. In vitro susceptibility tests of these three adhesive systems were performed by the minimum inhibitory/minimum bactericidal concentration (MIC/MBC) assays against Streptococcus mutans, Lactobacillus casei, and Actinomyces naeslundii. No statistically significant difference in ?TBS was observed between Clearfil™ SE Bond containing 5% QAMP and Clearfil™ SE Bond (p > 0.05) immediately, and after 6 and 12 months of water storage. However Clearfil™ Protect Bond showed a significant reduction of ?TBS after 12 months of storage (p = 0.039). In addition, QAMP provided no significant change in DC after incorporating into Clearfil™ SE Bond (p > 0.05). Clearfil™ SE Bond containing 5% QAMP demonstrated MIC/MBC values similar to the positive control against L. casei and A. naeslundii and higher than the negative control for all evaluated bacterial strains. The use of QAMP in an adhesive system demonstrated effective bond strength, a suitable degree of conversion, and adequate antibacterial effects against oral bacteria, and may be useful as a new approach to provide long-lasting results for dental adhesives. PMID:24853131

  11. Experimental determination of the ammonium partitioning among muscovite, K-feldspar, and aqueous chloride solutions

    NASA Astrophysics Data System (ADS)

    Pöter, Birgit; Gottschalk, Matthias; Heinrich, Wilhelm

    2004-05-01

    The cation exchange equilibria Muscovite+ NH4Cl? Tobelite+ KClKAl2AlSi3O10( OH) 2+ NH4Claq? NH4Al2AlSi3O10( OH) 2+ KClaqK- feldspar+ NH4Cl? Buddingtonite+ KClKAlSi3O8+ NH4Claq? NH4AlSi3O8+ KClaqare determined by hydrothermal experiments at 400, 500, 600 °C at 400 MPa, and piston cylinder experiments at 500, 600 °C at 1500 MPa along the entire K-NH 4 compositional range. The composition of solid phases are determined by XRD, EMP and FTIR-methods, NH 4-K ratios in coexisting 2-3 molal chloride solutions by ion chromatography. Muscovite-tobelite and K-feldspar-buddingtonite form complete solid solutions series at all conditions. Consistent phase relations and mass balances indicate equilibrium between solid solutions and fluids. In both the (K,NH 4)-muscovite and (K,NH 4)-feldspar-fluid systems, NH 4 strongly fractionates into the fluid. In the range from 400 to 600 °C, 400 to 1500 MPa, fractionations are slightly temperature and pressure-dependent. The distribution coefficient K Dsolid- fluid= {X NH4solid}/{X Ksolid}{X Kfluid}/{X NH4fluid}varies within the experimental range from 0.10 at XKbulk=0.81 to 0.46 at XKbulk=0.20 for muscovite-fluid, and from 0.05 at XKbulk=0.91 to 0.70 at XKbulk=0.15 for feldspar-fluid. NH 4 is preferentially incorporated into feldspar relative to mica with KDfsp-ms ranging between 1.36 and 2.0 at 400 MPa, and between 1.13 and 1.5 at 1500 MPa as XKbulk varies from 0.15 to 0.89. Results are evaluated thermodynamically assuming equal mixing of NH 4Cl and KCl in the fluid. Mixing energies of solids were estimated using multidimensional regression and a regular solution model. For the muscovite-tobelite equilibrium, values of ? s°=-11.7 J K -1 mol -1, ? v°=-2.1 J MPa -1 mol -1, and W=4.6 kJ mol -1, and for the K-feldspar-buddingtonite equilibrium, ? s°=-8.8 J K -1 mol -1, ? v°=-1.1 J MPa -1 mol -1, and W=5.4 kJ mol -1 were derived. Results are used to calculate partition coefficients D among phases at very low NH 4 bulk concentrations. Between 400 and 600 °C, DNH 4fluid-ms ranges from 7 to 8 at 400 MPa and is 5 at 1500 MPa. DNH 4fluid-ms is 6 to 7 at 400 MPa, and about 5 at 1500 MPa. DNH 4fsp-ms is between 1 and 1.2 at all conditions. Partition coefficients are valid for NH 4 contents of up to several hundred ppm in mica and feldspar, well within the concentration range observed in many rocks. Combining the data with that of K-NH 4-partitioning between phlogopite and fluid results in DNH 4phl-ms?3.5 and DNH 4phl-ms?3 at 550 °C, 200 to 400 MPa. NH 4 concentrations in coexisting muscovite, biotite, and K-feldspar from a variety of rocks show near-equilibrium distributions. NH 4-K-partitioning between major K-bearing minerals and saline fluids allows for assessment of the dehydration history of metamorphic rocks. During prograde metamorphism, water is progressively produced by dehydration reactions and expelled along rock's P- T path. Nitrogen is subsequently removed due to preferred fractionation of NH 4 into fluids. The remaining NH 4 is continuously redistributed among muscovite and biotite, and at higher grades, K-feldspar with biotite as the main solid phase carrier of ammonium. The large fractionation effect of NH 4 among most phases highlights its potential as tracer of devolatilization processes and fluid-rock interactions.

  12. Biocidal quaternary ammonium resin

    NASA Technical Reports Server (NTRS)

    Janauer, G. E.

    1983-01-01

    Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

  13. Synthesis, growth and characterization of non linear optical Bisthiourea ammonium chloride single crystals by slow evaporation technique

    NASA Astrophysics Data System (ADS)

    Ilango, E.; Rajasekaran, R.; Shankar, K.; Krishnan, S.; Chithambaram, V.

    2014-11-01

    A new semi-organic nonlinear optical crystal of Bisthiourea Ammonium Chloride (BTAC) has been grown by slow evaporation technique. The crystal system and lattice parameters were determined from X-ray diffraction. Fourier Transform Infrared (FTIR) studies confirm the various functional groups present in the grown crystal. The transmittance and absorbance of electromagnetic radiation is studied through UV-Visible spectrum. The thermal behavior of the grown crystals has been investigated by TG/DTA analysis. The dielectric constant and dielectric loss has been studied as a function of frequency for various temperatures and the result were discussed in detail. The SEM analysis was also done and it revealed the surface morphology of BTAC crystal. The second harmonic generation has been confirmed by the Kurtz powder test and it is found to be 1.4 times more than that of KDP crystal.

  14. Effect of varying nonwoven cotton substrate and the properties of the surfactant solution upon the adsorption of aqueous solutions of alkyl-dimethyl-benzyl-ammonium chloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations using UV/vis spectroscopy. Results show greige...

  15. Effect of varying nonwoven cotton substrate and the properties of the surfactant solution upon the adsorption of aqueous solutions of alkyl-dimethyl-benzyl-ammonium chloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached nonwoven cotton fabrics was investigated at varying surfactant concentrations and liquor ratios using UV-vis absorption spec...

  16. Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on low-weight greige and bleached cotton nonwovens in different aqueous environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research has shown the adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC) on cotton nonwovens is dependent on pretreatment of the substrate, more specifically whether it is greige or bleached fabric. In this work we examine the effect of varying the chemical and physical propert...

  17. Effect of polyester blends in hydroentangled raw and bleached cotton nonwoven fabrics on the adsorption of alkyl-dimethyl-benzyl-ammonium chloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adsorption kinetics and isotherms of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on hydroentangled nonwoven fabrics (applicable for wipes) including raw cotton, bleached cotton, and their blends with polyester (PES) were stu...

  18. Cationic quaternization of cellulose with methacryloyloxy ethyl trimethyl ammonium chloride via ATRP method

    NASA Astrophysics Data System (ADS)

    Supeno, Daik, Rusli; El-Sheikh, Said M.

    2014-09-01

    The synthesis of a cationic cellulose copolymer from cellulose macro-initiator (MCC-BiB) and quaternary compound monomer (METMA) via atom transfer radical polymerization (ATRP) was studied. By using dimethylformamide (DMF), the optimum condition for successful synthesis was at the mole ratio of MCC-BIB:Catalyst:METMA = 1:1:26. The highest copolymer recovery was 93.2 % for 6 h and at 40°C. The copolymer was insoluble in weak polar solvents such as THF and DMF but soluble in methanol and water. The chemistry of cellulose copolymer was confirmed by the FTIR and TGA in which the METMA monomer was used as a reference. The absence of CC bond in the CiB-g-METMA spectrum indicated that graft copolymerization occurred.

  19. Cationic quaternization of cellulose with methacryloyloxy ethyl trimethyl ammonium chloride via ATRP method

    SciTech Connect

    Supeno; Daik, Rusli; El-Sheikh, Said M.

    2014-09-03

    The synthesis of a cationic cellulose copolymer from cellulose macro-initiator (MCC-BiB) and quaternary compound monomer (METMA) via atom transfer radical polymerization (ATRP) was studied. By using dimethylformamide (DMF), the optimum condition for successful synthesis was at the mole ratio of MCC-BIB:Catalyst:METMA = 1:1:26. The highest copolymer recovery was 93.2 % for 6 h and at 40°C. The copolymer was insoluble in weak polar solvents such as THF and DMF but soluble in methanol and water. The chemistry of cellulose copolymer was confirmed by the FTIR and TGA in which the METMA monomer was used as a reference. The absence of CC bond in the CiB-g-METMA spectrum indicated that graft copolymerization occurred.

  20. The optical constants of several atmospheric aerosol species - Ammonium sulfate, aluminum oxide, and sodium chloride

    NASA Technical Reports Server (NTRS)

    Toon, O. B.; Pollack, J. B.; Khare, B. N.

    1976-01-01

    An investigation is conducted of problems which are related to a use of measured optical constants in the simulation of the optical constants of real atmospheric aerosols. The techniques of measuring optical constants are discussed, taking into account transmission measurements through homogeneous and inhomogeneous materials, the immersion of a material in a liquid of a known refractive index, the consideration of the minimum deviation angle of prism measurement, the interference of multiply reflected light, reflectivity measurements, and aspects of mathematical analysis. Graphs show the real and the imaginary part of the refractive index as a function of wavelength for aluminum oxide, NaCl, and ammonium sulfate. Tables are provided for the dispersion parameters and the optical constants.

  1. The role of hydroxyethyl groups in the construction of wormlike micelles in the system of quaternary ammonium surfactant and sodium salicylate.

    PubMed

    Dai, Caili; Wu, Xuepeng; Li, Weitao; You, Qin; Zhao, Mingwei; Du, Mingyong; Liu, Yifei; Li, Yuyang

    2015-10-21

    To understand the role of electrostatic interactions and hydrogen bonds in the formation of wormlike micelles with the aid of sodium salicylate, two quaternary ammonium surfactants with the headgroup decorated by one hydroxyethyl group N-cetyl-N-(2-hydroxyethyl)dimethylammonium bromide and two hydroxyethyl groups N-cetyl-N,N-di(2-hydroxyethyl)methylammonium bromide, abbreviated as CHEMAB and CDHAB, respectively, were synthesized in this work. Single crystal X-ray diffraction was used to study the intermolecular interactions of surfactants, and (1)H NMR and rheological measurements were employed to investigate the molecular arrangement and morphology of the wormlike micelles. The synergistic interactions of hydrogen bonding and more effective shielding of electrostatic repulsion contribute to the formation and viscoelastic behavior of wormlike micelles. The results also revealed the aggregation behavior of surfactants with hydroxyethyl headgroups in aqueous solutions. PMID:26314927

  2. AGING EFFECTS ON THE PROPERTIES OF IMIDAZOLIUM, QUATERNARY AMMONIUM, PYRIDINIUM AND PYRROLIDINIUM-BASED IONIC LIQUIDS USED IN FUEL AND ENERGY PRODUCTION

    SciTech Connect

    Fox, E.

    2013-08-13

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

  3. Synthesis and characterization of N-(2-hydroxy)propyl-3-trimethyl ammonium chitosan chloride for potential application in gene delivery.

    PubMed

    Xiao, Bo; Wan, Ying; Wang, Xiaoyu; Zha, Qichen; Liu, Haoming; Qiu, Zhiye; Zhang, Shengmin

    2012-03-01

    A series of N-(2-hydroxy)propyl-3-trimethyl ammonium chitosan chloride (HTCC) samples with various degrees of quaternization ranging from 12.4 to 43.7% was synthesized. The structures and properties of HTCC were investigated by FT-IR, (1)H NMR, conductometric titration and XRD analysis. It was found that HTCC had a more amorphous structure than chitosan. HTCC samples showed significantly lower cytotoxicity than polyethyleneimine in HepG2 and HeLa cell lines. The samples spontaneously formed complexes with pGL3 luciferase plasmid. These complexes had desirable particle sizes (160-300 nm) and zeta potentials (10.8-18.7 mV) when the weight ratios of HTCC to plasmid altered in the range of 3:1-20:1. In vitro gene transfection results indicated that HTCC had significantly high transfection efficiency compared with chitosan for delivering pGL3 luciferase plasmid to HeLa cells. The results suggest that HTCC could be a promising non-viral vector for safe and efficient DNA delivery. PMID:22104403

  4. Characterization of un-plasticized and propylene carbonate plasticized carboxymethyl cellulose doped ammonium chloride solid biopolymer electrolytes.

    PubMed

    Ahmad, N H; Isa, M I N

    2016-02-10

    Two solid biopolymer electrolytes (SBEs) systems of carboxymethyl cellulose doped ammonium chloride (CMC-AC) and propylene carbonate plasticized (CMC-AC-PC) were prepared via solution casting technique. The ionic conductivity of SBEs were analyzed using electrical impedance spectroscopy (EIS) in the frequency range of 50Hz-1MHz at ambient temperature (303K). The highest ionic conductivity of CMC-AC SBE is 1.43×10(-3)S/cm for 16wt.% of AC while the highest conductivity of plasticized SBE system is 1.01×10(-2)S/cm when added with 8wt.% of PC. TGA/DSC showed that the addition of PC had increased the decomposition temperature compared of CMC-AC SBE. Fourier transform infrared (FTIR) spectra showed the occurrence of complexation between the SBE components and it is proved successfully executed by Gaussian software. X-ray diffraction (XRD) indicated that amorphous nature of SBEs. It is believed that the PC is one of the most promising plasticizer to enhance the ionic conductivity and performance for SBE system. PMID:26686147

  5. Removal of As(V), Cr(III) and Cr(VI) from aqueous environments by poly(acrylonitril-co-acrylamidopropyl-trimethyl ammonium chloride)-based hydrogels.

    PubMed

    Dudu, Tuba Ersen; Sahiner, Mehtap; Alpaslan, Duygu; Demirci, Sahin; Aktas, Nahit

    2015-09-15

    Cationic poly(Acrylonitril-co-Acrylamidopropyl-trimethyl Ammonium Chloride) (p(AN-co-APTMACl)) hydrogels in bulk were synthesized by using acrylonitrile (AN) and 3-acrylamidopropyl-trimethyl ammonium chloride (APTMACl) as monomers. The prepared hydrogels were exposed to amidoximation reaction to replace hydrophobic nitrile groups with hydrophilic amidoxime groups that have metal ion binding ability. Those replacements were increased the hydrogels absorption capacity for As(V) and Cr(VI). Langmuir and Freundlich isotherms equations were utilized to obtain the best-fitted isotherm model for the absorption of the ions at different metal ion concentrations. The absorption data of As(V) ion were fitted well to Freundlich isotherm while those of Cr(VI) and Cr(III) ions were fitted well to Langmuir isotherm. The maximum absorption of poly(3-acrylamidopropyl-trimethyl ammonium chloride (p(APTMACl)) and amid-p(AN-co-APTMACl) macro gels were 22.39 mg and 21.83 mg for As(V), and 30.65 mg and 18.16 mg for Cr(VI) ion per unit gram dried gel, respectively. Kinetically, the absorption behaviors of Cr(III) and Cr(VI) ions were fitted well to a pseudo 2nd-order kinetic model and those of As(V) ions were fitted well to a pseudo 1st order kinetic model. PMID:26188989

  6. Evaluation of Antimicrobial Efficiency of New Polymers Comprised by Covalently Attached and/or Electrostatically Bound Bacteriostatic Species, Based on Quaternary Ammonium Compounds.

    PubMed

    Kougia, Efstathia; Tselepi, Maria; Vasilopoulos, Gavriil; Lainioti, Georgia Ch; Koromilas, Nikos D; Druvari, Denisa; Bokias, Georgios; Vantarakis, Apostolos; Kallitsis, Joannis K

    2015-01-01

    In the present work a detailed study of new bacteriostatic copolymers with quaternized ammonium groups introduced in the polymer chain through covalent attachment or electrostatic interaction, was performed. Different copolymers have been considered since beside the active species, the hydrophobic/hydrophilic nature of the co-monomer was also evaluated in the case of covalently attached bacteriostatic groups, aiming at achieving permanent antibacterial activity. Homopolymers with quaternized ammonium/phosphonium groups were also tested for comparison reasons. The antimicrobial activity of the synthesized polymers after 3 and 24 h of exposure at 4 and 22 °C was investigated on cultures of Gram-negative (P. aeruginosa, E. coli) and Gram-positive (S. aureus, E. faecalis) bacteria. It was found that the combination of the hydrophilic monomer acrylic acid (AA), at low contents, with the covalently attached bacteriostatic group vinyl benzyl dimethylhexadecylammonium chloride (VBCHAM) in the copolymer P(AA-co-VBCHAM88), resulted in a high bacteriostatic activity against P. aeruginosa and E. faecalis (6 log reduction in certain cases). Moreover, the combination of covalently attached VBCHAM units with electrostatically bound cetyltrimethylammonium 4-styrene sulfonate (SSAmC16) units in the P(SSAmC16-co-VBCHAMx) copolymers led to efficient antimicrobial materials, especially against Gram-positive bacteria, where a log reduction between 4.9 and 6.2 was verified. These materials remain remarkably efficient even when they are incorporated in polysulfone membranes. PMID:26633329

  7. In Vitro Antibacterial Activity of a Novel Resin-Based Pulp Capping Material Containing the Quaternary Ammonium Salt MAE-DB and Portland Cement

    PubMed Central

    Zhang, Hongchen; Zhou, Wei; Ban, Jinghao; Wei, Jingjing; Liu, Yan; Gao, Jing; Chen, Jihua

    2014-01-01

    Background Vital pulp preservation in the treatment of deep caries is challenging due to bacterial infection. The objectives of this study were to synthesize a novel, light-cured composite material containing bioactive calcium-silicate (Portland cement, PC) and the antimicrobial quaternary ammonium salt monomer 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB) and to evaluate its effects on Streptococcus mutans growth in vitro. Methods The experimental material was prepared from a 2?1 ratio of PC mixed with a resin of 2-hydroxyethylmethacrylate, bisphenol glycerolate dimethacrylate, and triethylene glycol dimethacrylate (4?3?1) containing 5 wt% MAE-DB. Cured resin containing 5% MAE-DB without PC served as the positive control material, and resin without MAE-DB or PC served as the negative control material. Mineral trioxide aggregate (MTA) and calcium hydroxide (Dycal) served as commercial controls. S. mutans biofilm formation on material surfaces and growth in the culture medium were tested according to colony-forming units (CFUs) and metabolic activity after 24 h incubation over freshly prepared samples or samples aged in water for 6 months. Biofilm formation was also assessed by Live/Dead staining and scanning electron microscopy. Results S. mutans biofilm formation on the experimental material was significantly inhibited, with CFU counts, metabolic activity, viability staining, and morphology similar to those of biofilms on the positive control material. None of the materials affected bacterial growth in solution. Contact-inhibition of biofilm formation was retained by the aged experimental material. Significant biofilm formation was observed on MTA and Dycal. Conclusion The synthesized material containing HEMA-BisGMA-TEGDMA resin with MAE-DB as the antimicrobial agent and PC to support mineralized tissue formation inhibited S. mutans biofilm formation even after aging in water for 6 months, but had no inhibitory effect on bacteria in solution. Therefore, this material shows promise as a pulp capping material for vital pulp preservation in the treatment of deep caries. PMID:25389975

  8. Evaluation of aqueous and alcohol-based quaternary ammonium sanitizers for inactivating Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes on peanut and pistachio shells.

    PubMed

    McEgan, Rachel; Danyluk, Michelle D

    2015-05-01

    This study evaluated the efficacy of aqueous (aQUAT) and isopropyl alcohol-based quaternary ammonium (ipQUAT) sanitizers for reducing Salmonella spp., Escherichia coli O157:H7, or Listeria monocytogenes populations on peanut and pistachio shell pieces. Inoculated nutshells were mixed with QUAT sanitizers, water, or 70% ethanol and enumerated immediately or after incubation at 30 °C for 48 h. None of the treatments had any immediate effect on Salmonella or E. coli O157:H7 populations on the peanut or pistachio shells. L. monocytogenes populations declined immediately on the peanut and pistachio shells treated with aQUAT or ipQUAT. After incubation, Salmonella and E. coli O157:H7 populations increased significantly on the water- or aQUAT-treated peanut and pistachio shells. L. monocytogenes populations also increased significantly on the water- or aQUAT-treated peanut shells, but levels did not change on the water-treated pistachio shells and levels were just above the limit of detection on the aQUAT-treated pistachio shells. After treatment with ipQUAT and 48-h incubation, Salmonella and E. coli O157:H7 populations decreased to or below the limit of detection on both shell types; L. monocytogenes populations remained at or below the limit of detection on both shell types. PMID:25583342

  9. Simultaneous determination of phosphatidylcholine-derived quaternary ammonium compounds by a LC-MS/MS method in human blood plasma, serum and urine samples.

    PubMed

    Steuer, Christian; Schütz, Philipp; Bernasconi, Luca; Huber, Andreas R

    2016-01-01

    The determination of circulating trimethylamine-N-oxide (TMAO), choline, betaine, l-carnitine and O-acetyl-l-carnitine concentration in different human matrices is of great clinical interest. Recent results highlighted the prognostic value of TMAO and quaternary ammonium containing metabolites in the field of cardiovascular and kidney diseases. Herein, we report a method for the rapid and simultaneous measurement of closely related phosphatidylcholine-derived metabolites in three different biological matrices by stable isotope dilution assay. Plasma, serum and urine samples were simply deproteinized and separated by HILIC-chromatography. Detection and quantification were performed using LC-MS/MS with electrospray ionization in positive mode. For accuracy and precision, full calibration was performed covering more than the full reference range. Assay performance metrics include intra- and interday imprecision were below 10% for all analytes. To exclude matrix effects standard addition methods were applied for all matrices. It was shown that calibration standards and quality control prepared in water can be used instead of matrix-matched calibration and controls. The LC/MS/MS-based assay described in this article may improve future clinical studies evaluating TMAO and related substances as prognostic markers for cardiovascular risk and all-cause mortality in different patient populations. PMID:26673229

  10. QSAR study on maximal inhibition (Imax) of quaternary ammonium antagonists for S-(-)-nicotine-evoked dopamine release from dopaminergic nerve terminals in rat striatum.

    PubMed

    Zheng, Fang; McConnell, Matthew J; Zhan, Chang-Guo; Dwoskin, Linda P; Crooks, Peter A

    2009-07-01

    Maximal inhibition (I(max)) of the agonist effect is an important pharmacological property of inhibitors that interact with multiple receptor subtypes that are activated by the same agonist and which elicit the same functional response. This report represents the first QSAR study on a set of 66 mono- and bis-quaternary ammonium salts that act as antagonists at neuronal nicotinic acetylcholine receptors mediating nicotine-evoked dopamine release, conducted using multi-linear regression (MLR) and neural network (NN) analysis with the maximal inhibition (I(max)) values of the antagonists as target values. The statistical results for the generated MLR model were: r(2)=0.89, rmsd=9.01, q(2)=0.83 and loormsd=11.1; the statistical results for the generated NN model were: r(2)=0.89, rmsd=8.98, q(2)=0.83 and loormsd=11.2. The maximal inhibition values of the compounds exhibited a good correlation with the predictions made by the QSAR models developed, which provide a basis for rationalizing selection of compounds for synthesis in the discovery of effective and selective second generation inhibitors of nAChRs mediating nicotine-evoked dopamine release. PMID:19477134

  11. Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

    PubMed Central

    Jeon, Jong Yeob; Eo, Seong Chan; Varghese, Jobi Kodiyan

    2014-01-01

    Summary The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalate)s were afforded without any formation of ether linkages. In the PO/CO2/PA terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalate)s because of the drift in the PA concentration during the terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1) and the number of chain-growing sites per 1 [anions in 1 (5) + water (present as impurity) + ethanol (deliberately fed)], and the molecular weight distributions were narrow (M w/M n, 1.05–1.5). Because of the extremely high activity of 1, high-molecular-weight polymers were generated (M n up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA terpolymerization, respectively). The terpolymers bearing a substantial number of PA units (f PA, 0.23) showed a higher glass-transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C). PMID:25161738

  12. Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts.

    PubMed

    Jeon, Jong Yeob; Eo, Seong Chan; Varghese, Jobi Kodiyan; Lee, Bun Yeoul

    2014-01-01

    The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalate)s were afforded without any formation of ether linkages. In the PO/CO2/PA terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalate)s because of the drift in the PA concentration during the terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1) and the number of chain-growing sites per 1 [anions in 1 (5) + water (present as impurity) + ethanol (deliberately fed)], and the molecular weight distributions were narrow (M w/M n, 1.05-1.5). Because of the extremely high activity of 1, high-molecular-weight polymers were generated (M n up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA terpolymerization, respectively). The terpolymers bearing a substantial number of PA units (f PA, 0.23) showed a higher glass-transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C). PMID:25161738

  13. QSAR study on maximal inhibition (Imax) of quaternary ammonium antagonists for S-(?)-nicotine-evoked dopamine release from dopaminergic nerve terminals in rat striatum

    PubMed Central

    Zheng, Fang; McConnell, Matthew J.; Zhan, Chang-Guo; Dwoskin, Linda P.; Crooks, Peter A.

    2013-01-01

    Maximal inhibition (Imax) of the agonist effect is an important pharmacological property of inhibitors that interact with multiple receptor subtypes that are activated by the same agonist and which elicit the same functional response. This report represents the first QSAR study on a set of 66 mono- and bis-quaternary ammonium salts that act as antagonists at neuronal nicotinic acetylcholine receptors mediating nicotine-evoked dopamine release, conducted using multi-linear regression (MLR) and neural network (NN) analysis with the maximal inhibition (Imax) values of the antagonists as target values. The statistical results for the generated MLR model were: r2 = 0.89, rmsd = 9.01, q2 = 0.83 and loormsd = 11.1; the statistical results for the generated NN model were: r2 = 0.89, rmsd = 8.98, q2 = 0.83 and loormsd = 11.2. The maximal inhibition values of the compounds exhibited a good correlation with the predictions made by the QSAR models developed, which provide a basis for rationalizing selection of compounds for synthesis in the discovery of effective and selective second generation inhibitors of nAChRs mediating nicotine-evoked dopamine release. PMID:19477134

  14. Quaternary Ammonium Oxidative Demethylation: X-ray Crystallographic, Resonance Raman and UV-visible Spectroscopic Analysis of a Rieske-type Demethylase

    SciTech Connect

    Daughtry K. D.; Orville A.; Xiao, Y.; Stoner-Ma, D.; Cho, E.; Liu, P.; Allen, K. N.

    2012-02-01

    Herein, the structure resulting from in situ turnover in a chemically challenging quaternary ammonium oxidative demethylation reaction was captured via crystallographic analysis and analyzed via single-crystal spectroscopy. Crystal structures were determined for the Rieske-type monooxygenase, stachydrine demethylase, in the unliganded state (at 1.6 {angstrom} resolution) and in the product complex (at 2.2 {angstrom} resolution). The ligand complex was obtained from enzyme aerobically cocrystallized with the substrate stachydrine (N,N-dimethylproline). The ligand electron density in the complex was interpreted as proline, generated within the active site at 100 K by the absorption of X-ray photon energy and two consecutive demethylation cycles. The oxidation state of the Rieske iron-sulfur cluster was characterized by UV-visible spectroscopy throughout X-ray data collection in conjunction with resonance Raman spectra collected before and after diffraction data. Shifts in the absorption band wavelength and intensity as a function of absorbed X-ray dose demonstrated that the Rieske center was reduced by solvated electrons generated by X-ray photons; the kinetics of the reduction process differed dramatically for the liganded complex compared to unliganded demethylase, which may correspond to the observed turnover in the crystal.

  15. Bifunctional quaternary ammonium compounds to inhibit biofilm growth and enhance performance for activated carbon air-cathode in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Nan; Liu, Yinan; An, Jingkun; Feng, Cuijuan; Wang, Xin

    2014-12-01

    The slow diffusion of hydroxyl out of the catalyst layer as well as the biofouling on the surface of cathode are two problems affecting power for membrane-less air-cathode microbial fuel cells (MFCs). In order to solve both of them simultaneously, here we simply modify activated carbon air-cathode using a bifunctional quaternary ammonium compound (QAC) by forced evaporation. The maximum power density reaches 1041 ± 12 mW m-2 in an unbuffered medium (0.5 g L-1 NaCl), which is 17% higher than the control, probably due to the accelerated anion transport in the catalyst layer. After 2 months, the protein content reduced by a factor of 26 and the power density increases by 33%, indicating that the QAC modification can effectively inhibit the growth of cathodic biofilm and improve the stability of performance. The addition of NaOH and QAC epoxy have a negative effect on power production due to the clogging of pores in catalyst layer.

  16. Structural characterization of zinc(II) chloride in aqueous solution and in the protic ionic liquid ethyl ammonium nitrate by x-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    D'Angelo, Paola; Zitolo, Andrea; Ceccacci, Francesca; Caminiti, Ruggero; Aquilanti, Giuliana

    2011-10-01

    Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to investigate the species and structures existing in a series of ZnCl2-H2O-NaCl solutions with different chloride/zinc ratios and in a solution of ZnCl2 in the protic ionic liquid ethyl ammonium nitrate (EAN). The average coordination numbers and distances of zinc species were determined from the analysis of the EXAFS data. In aqueous solution the number of chloride ions tightly bounded to Zn2+ is significantly related to the chloride/zinc ratio, and no inner complex formation between Zn2+ and Cl- ions has been detected for low ZnCl2 concentration (0.1 and 0.2 M). Conversely, in the same concentration range (0.13 M) the ZnCl2 species do not dissociate in EAN and the Zn2+ first coordination shell has two chloride ions and is completed by two oxygen atoms of the nitrate anion. The results of this investigation show that notwithstanding the existence of similar characteristics between EAN and water, the solvation properties of the two solvents are markedly different.

  17. N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride nanoparticle as a novel delivery system for parathyroid hormone-related protein 1-34.

    PubMed

    Zhao, Sheng-hao; Wu, Xiao-ting; Guo, Wei-chun; Du, Yu-min; Yu, Ling; Tang, Jin

    2010-06-30

    Chitosan (CS) and epoxy propyl trimethyl ammonium chloride (EPTAC) were used to prepare the water-soluble N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC). HTCC and sodium tripolyphosphate (TPP) were mixed to form HTCC nanoparticles based on ionic gelation. Parathyroid hormone-related protein 1-34 (PTHrP1-34) was incorporated into the HTCC nanoparticles. The particle size and morphology of nanoparticles were determined by transmission electron microscopy (TEM). HTCC/PTHrP1-34 nanoparticles were 100-180 nm in size and their encapsulation efficiency and loading capacity were related to HTCC concentration, TPP concentration and initial concentration of PTHrP1-34. Relatively optimum encapsulation efficiency (78.4%) and loading capacity (13.7%) of PTHrP1-34 is achieved, and the in vitro release profile of PTHrP1-34 from nanoparticles has an initial burst, which is followed up by a slow release phase. These studies showed that HTCC/PTHrP1-34 nanoparticles are suitable for the treatment of osteoporosis, because of their slow-continuous-release properties, and the relevant in vivo experiments and clinical trials should be further studied. PMID:20435115

  18. Achieving significantly enhanced visible-light photocatalytic efficiency using a polyelectrolyte: the composites of exfoliated titania nanosheets, graphene, and poly(diallyl-dimethyl-ammonium chloride)

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; An, Qi; Luan, Xinglong; Huang, Hongwei; Li, Xiaowei; Meng, Zilin; Tong, Wangshu; Chen, Xiaodong; Chu, Paul K.; Zhang, Yihe

    2015-08-01

    A high-performance visible-light-active photocatalyst is prepared using the polyelectrolyte/exfoliated titania nanosheet/graphene oxide (GO) precursor by flocculation followed by calcination. The polyelectrolyte poly(diallyl-dimethyl-ammonium chloride) serves not only as an effective binder to precipitate GO and titania nanosheets, but also boosts the overall performance of the catalyst significantly. Unlike most titania nanosheet-based catalysts reported in the literature, the composite absorbs light in the UV-Vis-NIR range. Its decomposition rate of methylene blue is 98% under visible light. This novel strategy of using a polymer to enhance the catalytic performance of titania nanosheet-based catalysts affords immense potential in designing and fabricating next-generation photocatalysts with high efficiency.A high-performance visible-light-active photocatalyst is prepared using the polyelectrolyte/exfoliated titania nanosheet/graphene oxide (GO) precursor by flocculation followed by calcination. The polyelectrolyte poly(diallyl-dimethyl-ammonium chloride) serves not only as an effective binder to precipitate GO and titania nanosheets, but also boosts the overall performance of the catalyst significantly. Unlike most titania nanosheet-based catalysts reported in the literature, the composite absorbs light in the UV-Vis-NIR range. Its decomposition rate of methylene blue is 98% under visible light. This novel strategy of using a polymer to enhance the catalytic performance of titania nanosheet-based catalysts affords immense potential in designing and fabricating next-generation photocatalysts with high efficiency. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03256c

  19. Theoretical studies on the reaction of mono- and ditriflate derivatives of 1,4:3,6-dianhydro-D-mannitol with trimethylamine-Can a quaternary ammonium salt be a source of the methyl group?

    PubMed

    Bednarko, Justyna; Wieli?ska, Justyna; Sikora, Karol; Liberek, Beata; Nowacki, Andrzej

    2016-01-01

    DFT studies on the mechanism of the formation of "gemini" quaternary ammonium salts in the reaction of 1,4:3,6-dianhydro-D-mannitol ditriflate derivative with trimethylamine and its subsequent conversion to tertiary amine through the methyl-transfer reaction are discussed. Two alternative reaction pathways are presented in the gas phase and in ethanol. Additionally, the transformation of the monotriflate derivative of 1,4:3,6-dianhydro-D-mannitol into the single quaternary ammonium salt is presented. Two functionals (B3LYP, M062X) and two basis sets (6-31+G** and 6-311++G**) were used for the calculations. The effect of the substituent attached to the five-membered rings at the C2 (and/or C5) carbon atom on the activation barrier is described. The trimethylammonium group bond to the five-membered ring greatly reduces the activation barrier height. The preferred reaction pathway for the conversions was established. Including the London dispersion in the calculations increases the stabilization of all the points on the potential energy surface in relation to individual reactants. PMID:26667239

  20. A second polymorph of bis­(triphenyl-?5-phosphanyl­idene)ammonium chloride–boric acid adduct

    PubMed Central

    Correia Bicho, Bruno A.; Bolli, Christoph; Jenne, Carsten; Seeger, Helene

    2013-01-01

    The title crystal structure is a new triclinic polymorph of [(Ph3P)2N]Cl·(B(OH)3) or C36H30NP2 +·Cl?·BH3O3. The crystal structure of the ortho­rhom­bic polymorph was reported by [Andrews et al. (1983 ?). Acta Cryst. C39, 880–882]. In the crystal, the [(Ph3P)2N]+ cations have no significant contacts to the chloride ions nor to the boric acid mol­ecules. This is indicated by the P—N—P angle of 137.28?(8)°, which is in the expected range for a free [(Ph3P)2N]+ cation. The boric acid mol­ecules form inversion dimers via pairs of O—H?O hydrogen bonds, and each boric acid mol­ecule forms two additional O—H?Cl hydrogen bonds to one chloride anion. These entities fill channels, created by the [(Ph3P)2N]+ cations, along the c-axis direction. PMID:24427065

  1. Infrared band intensities in ammonium hydroxide and ammonium salts

    NASA Technical Reports Server (NTRS)

    Sethna, P. P.; Downing, H. D.; Pinkley, L. W.; Williams, D.

    1978-01-01

    We have applied Kramers-Kronig analysis to reflection spectra to determine the optical constants of ammonium hydroxide and of aqueous solutions of ammonium chloride and bromide. From considerations of the absorption indices k(nu) we conclude that ammonium hydroxide consists of a solution of NH3 in water, in which NH3 molecules are hydrogen bonded to neighboring water molecules. The spectrum of ammonium hydroxide differs from the spectra of ammonium salts, in which bands characteristic of NH4(+) ions are prominent. The existence of ammonium hydroxide as an aerosol in planetary atmospheres is briefly discussed

  2. Selective encapsulation of chloride ions within novel cage host complexes in the presence of equimolar amounts of chloride and bromide ions.

    PubMed

    Ichikawa, K; Izumi, M; Goto, D; Ito, N

    2001-12-01

    Four macrotricyclic cage hosts which feature four positive binding sites oriented toward the center of the intramolecular cavity are presented as promising candidates for anion receptors and they have been expected to play a important role in the selective encapsulation of the halide ion Cl- or Br . The complementarity between a macrotricyclic quaternary ammonium ion and Cl- was achieved by fine-tuning of the four ammonium nitrogen atoms and the endocyclic methylene groups. The cage hosts [R4N4(C5H10)4(C6H12)2]4+ (abbreviated as [556]) showed perfect encapsulation of all chloride ions in acetonitrile at 0 < r= ([Cl-]o/[[556

  3. Electrodialytic Transport Properties of Anion-Exchange Membranes Prepared from Poly(vinyl alcohol) and Poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride)

    PubMed Central

    Jikihara, Atsushi; Ohashi, Reina; Kakihana, Yuriko; Higa, Mitsuru; Kobayashi, Kenichi

    2012-01-01

    Random-type anion-exchange membranes (AEMs) have been prepared by blending poly(vinyl alcohol) (PVA) and the random copolymer-type polycation, poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride) at various molar percentages of anion-exchange groups to vinyl alcohol groups, Cpc, and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations, CGA. The characteristics of the random-type AEMs were compared with blend-type AEMs prepared in our previous study. At equal molar percentages of the anion exchange groups, the water content of the random-type AEMs was lower than that of the blend-type AEMs. The effective charge density of the random-type AEMs increased with increasing Cpc and reached a maximum value. Further, the maximum value of the effective charge density increased with increasing CGA. The maximum value of the effective charge density, 0.42 mol/dm3, was obtained for the random-type AEM with Cpc = 4.2 mol % and CGA = 0.15 vol %. A comparison of the random-type and blend-type AEMs with almost the same Cpc showed that the random-type AEMs had lower membrane resistance than the blend-type ones. The membrane resistance and dynamic transport number of the random-type AEM with Cpc = 6.0 mol % and CGA = 0.15 vol % were 4.8 ? cm2 and 0.83, respectively. PMID:24958543

  4. The use of superporous p(3-acrylamidopropyl)trimethyl ammonium chloride cryogels for removal of toxic arsenate anions.

    PubMed

    Sahiner, Nurettin; Demirci, Sahin; Sahiner, Mehtap; Yilmaz, Selahattin; Al-Lohedan, Hamad

    2015-04-01

    Poly((3-Acrylamidopropyl)trimethylammonium chloride) (p(APTMACl)) cryogels were used as a superporous polymer network for the removal of toxic arsenate anions from an aqueous medium. The fast swelling in water, in about 7 s, was shown to be very useful leading to fast arsenate adsorption by p(APTMACl) cryogels within 30 min in comparison to 12 h for bulk common p(APTMACl) hydrogels. A maximum adsorption capacity of about 120 (mg/g) arsenate was obtained for p(APTMACl) cryogels. Both the Langmuir and Freundlich adsorption isotherms were applied for adsorption of arsenate anions by p(APTMACl) cryogels, and it was observed that the adsorption of arsenate anions by p(APTMACl) cryogels are represented better via Langmuir adsorption isotherm providing the R(2) value of 0.998. Furthermore, mag-p(APTMACl) cryogels were synthesized, and shown to be very useful in the fast removal of toxic arsenate anions. The mag-p(APTMACl) cryogels including the adsorbed arsenate were removed by an externally applied magnetic field, with some reduction in the arsenate ion adsorption capacity. It was also further demonstrated that p(APTMACl) cryogels can be reused in the adsorption of arsenate 5 times from aqueous environments without significant loss of adsorption capacity, from 113.47 ± 9 to 102.67 ± 6 mg/g. PMID:25617870

  5. Ammonium action on post-synaptic inhibition in crayfish neurones: implications for the mechanism of chloride extrusion

    PubMed Central

    Aickin, C. Claire; Deisz, R. A.; Lux, H. D.

    1982-01-01

    1. The reversal potential of the Cl--dependent, inhibitory post-synaptic potential (Ei.p.s.p.) was measured in the isolated crayfish stretch receptor neurone using two intracellular micro-electrodes. The difference between Ei.p.s.p. and the resting membrane potential (Em), the i.p.s.p. driving force, was reversibly decreased by addition of NH3/NH4+, and the mechanism of this decrease was investigated. 2. The NH3/NH4+-induced decrease in i.p.s.p. driving force was dose-dependent with an onset at about 0·2 mM. Ei.p.s.p. always remained more negative than Em or, when the neurone was spontaneously firing, the threshold potential. Em and resting membrane resistance (Rm) also decreased in a dose-dependent fashion. Synaptic conductance (gs) increased with low doses, but decreased on application of 20 mM-NH3/NH4+. All the effects were fully reversible on return to normal Ringer solution. 3. Intracellular acidification (substitution of 50% Cl- by acetate compared with isethionate) considerably reduced the i.p.s.p. driving force. Simultaneous application of NH3/NH4+ and acetate-substituted Ringer solution caused a similar decrease in the driving force to application of the same concentration of NH3/NH4+ under normal conditions. Increasing the extracellular pH at which a given concentration of NH3/NH4+ was applied caused a smaller decline in the i.p.s.p. driving force. These results suggest that intracellular acidification decreases the i.p.s.p. driving force and that the NH3/NH4+-induced decline is caused by an action of the ammonium ion. 4. Elevation of extracellular K+ (K+0) decreased the i.p.s.p. driving force, Em and Rm, and increased gs. Reduction of K+0 had the converse effects on all parameters. 5. Application of Rb+ or Cs+ mimicked the effects of NH3/NH4+. Substitution of K+0 by Rb+, Cs+ or NH3/NH4+ opposed or even reversed the increase in i.p.s.p. driving force when Na+ was used as the substitute. The effectiveness of the various cations in decreasing the driving force was in the following order: Rb+ > NH4+ > K+ > Cs+. 6. Inhibition of the Na pump by ouabain or K+-free Ringer solution caused a gradual reduction in the i.p.s.p. driving force. Since the driving force also decreased when the Na+ gradient probably was increased (elevated K+0), this suggests a dependence on the K+ gradient rather than the Na+ gradient or the Na pump itself. 7. Frusemide (6 × 10-4 M) reversibly decreased the i.p.s.p. driving force and Em, and increased gs. Rm was not significantly affected. Application of frusemide in the presence of 5 mM-Rb+ and vice versa, caused a further reduction in the driving force. The recovery of the driving force on removal of either agent was slowed by the presence of the other. 8. Application of 4,4-diisothiocyanostilbene-2,2-disulphonic acid (DIDS; 10-4 M) caused spontaneous firing and reduced Ei.p.s.p. to the threshold potential. Rm and gs increased. The effects were slowly reversible on removal of the drug. 9. It is proposed that the i.p.s.p. driving force is maintained by a K+—Cl- co-transport mechanism, driven by the K+ gradient. The K+ site exhibits the binding selectivity: Rb+ > NH4+ > K+ > Cs+ and the mechanism is inhibited partially by frusemide and completely by DIDS. PMID:7143250

  6. Benzalkonium chloride. Health hazard evaluation report

    SciTech Connect

    Bernholc, N.M.

    1984-01-01

    Health hazards associated with the use of benzalkonium chlorides (BAC) are reviewed. Benzalkonium chloride is extensively used as a cationic disinfectant. It is found in a great many over-the-counter and prescription eye products, disinfectants, shampoos, and deodorants, and is used in concentrations that range from 0.001 to 0.01% in eyedrops, up to 2.5% in concentrated liquid disinfectants. Solutions of 0.03 to 0.04% BAC may cause temporary eye irritation in humans but are unlikely to cause any skin response except in persons allergic to quaternary ammonium compounds. Inhalation of a vaporized 10% solution of BAC produced a bronchospasmodic reaction in a previously sensitized individual. At present no other human health effects from BAC have been documented or inferred from exposure to such dilute concentrations.

  7. Effects of ion pairing on the capillary electrophoretic separation and ultraviolet-absorption detection of quaternary ammonium cations using meso-octamethylcalix[4]pyrrole as the background electrolyte additive.

    PubMed

    Luo, Mina; Ma, Huaqiao; Chen, Fu

    2015-04-01

    Five quaternary ammonium cations, including tetramethylammonium, tetraethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, and 1-butyl-3-methylimidazolium, have been separated by capillary electrophoresis. A direct ultraviolet method has been achieved when tetrabutylammonium fluoride was the background electrolyte and meso-octamethylcalix[4]pyrrole was the background electrolyte additive. The ultraviolet spectra of meso-octamethylcalix[4]pyrrole and cation mixtures showed that redshifts can be attributed to the size of cations, and the maximum absorption wavelength shifted from 218 to 230 nm when tetrabutylammonium cation was substituted with tetramethylammonium cation or tetraethylammonium cation. Conductivity measurements were performed to evaluate the ion-pairing effect of tetrabutylammonium fluoride in a mixture of acetonitrile/ethanol (80:20, v/v), and the ion-pairing formation constant, Kip, was calculated (Kip = 14.8 ± 0.3 L/mol) using the Fuoss extended model. Ion pairing also occurs between cations of the analytes and counterion, a fluoride complex of meso-octamethylcalix[4]pyrrole. The tetramethylammonium cations associate more strongly with this counterion than the tetraethylammonium cation that contributes to the change of selectivity in capillary electrophoresis separation. The effective mobilities of the cations with trimethyl groups, such as tetramethylammonium cation, benzyltrimethylammonium cation, and hexadecyltrimethylammonium cation, decreased faster than others with the increase of meso-octamethylcalix[4]pyrrole concentration, highlighting the fact that the ion-pairing effect played an important role in this method. PMID:25641935

  8. Mutational upregulation of a resistance-nodulation-cell division-type multidrug efflux pump, SdeAB, upon exposure to a biocide, cetylpyridinium chloride, and antibiotic resistance in Serratia marcescens.

    PubMed

    Maseda, Hideaki; Hashida, Yumiko; Konaka, Rumi; Shirai, Akihiro; Kourai, Hiroki

    2009-12-01

    Serratia marcescens is an important opportunistic pathogen in hospitals, where quaternary ammonium compounds are often used for disinfection. The aim of this study is to elucidate the effect of a biocide on the emergence of biocide- and antibiotic-resistant mutants and to characterize the molecular mechanism of biocide resistance in Serratia marcescens. A quaternary ammonium compound-resistant strain, CRes01, was selected by exposing a wild-type strain of S. marcescens to cetylpyridinium chloride. The CRes01 cells exhibited 2- to 16-fold more resistance than the wild-type cells to biocides and antibiotics, including cetylpyridinium chloride, benzalkonium chloride, chlorhexidine gluconate, fluoroquinolones, tetracycline, and chloramphenicol, and showed increased susceptibilities to beta-lactam antibiotics and N-dodecylpyridinium iodide. Mutant cells accumulated lower levels of norfloxacin than the parent cells in an energized state but not in a de-energized state, suggesting that the strain produced a multidrug efflux pump(s). To verify this assumption, we knocked out a putative efflux pump gene, sdeAB, in CRes01 and found that the knockout restored susceptibility to most quaternary ammonium compounds and antibiotics, to which the CRes01 strain showed resistance. On the basis of these and other results, we concluded that S. marcescens gains resistance to both biocides and antibiotics by expressing the SdeAB efflux pump upon exposure to cetylpyridinium chloride. PMID:19752278

  9. Capillary electrophoresis of chitooligosaccharides in acidic solution: simple determination using a quaternary-ammonium-modified column and indirect photometric detection with crystal violet.

    PubMed

    Hattori, Toshiaki; Anraku, Nobuhiro; Kato, Ryo

    2010-02-01

    Five chitosan oligosaccharides were separated in acidic aqueous solution by capillary electrophoresis (CE) with indirect photometric detection using a positively coated capillary. Electrophoretic mobility of the chitooligosaccharides (COSs) depended on the number of monomer units in acidic aqueous solution, similar to other polyelectrolyte oligomers. The separation was developed in nitric acid aqueous solution at pH 3.0 with 1 mM Crystal Violet, using a capillary positively coated with N-trimethoxypropyl-N,N,N-trimethylammonium chloride. The limit of the detection for chitooligosaccharides with two to six saccharide chains was less than 5 microM. CE determination of an enzymatically hydrolyzed COS agreed with results from HPLC. PMID:20004627

  10. Evaluation of reduced susceptibility to quaternary ammonium compounds and bisbiguanides in clinical isolates and laboratory-generated mutants of Staphylococcus aureus.

    PubMed

    Furi, Leonardo; Ciusa, Maria Laura; Knight, Daniel; Di Lorenzo, Valeria; Tocci, Nadia; Cirasola, Daniela; Aragones, Lluis; Coelho, Joana Rosado; Freitas, Ana Teresa; Marchi, Emmanuela; Moce, Laura; Visa, Pilar; Northwood, John Blackman; Viti, Carlo; Borghi, Elisa; Orefici, Graziella; Morrissey, Ian; Oggioni, Marco Rinaldo

    2013-08-01

    The MICs and minimum bactericidal concentrations (MBCs) for the biocides benzalkonium chloride and chlorhexidine were determined against 1,602 clinical isolates of Staphylococcus aureus. Both compounds showed unimodal MIC and MBC distributions (2 and 4 or 8 mg/liter, respectively) with no apparent subpopulation with reduced susceptibility. To investigate further, all isolates were screened for qac genes, and 39 of these also had the promoter region of the NorA multidrug-resistant (MDR) efflux pump sequenced. The presence of qacA, qacB, qacC, and qacG genes increased the mode MIC, but not MBC, to benzalkonium chloride, while only qacA and qacB increased the chlorhexidine mode MIC. Isolates with a wild-type norA promoter or mutations in the norA promoter had similar biocide MIC distributions; notably, not all clinical isolates with norA mutations were resistant to fluoroquinolones. In vitro efflux mutants could be readily selected with ethidium bromide and acriflavine. Multiple passages were necessary to select mutants with biocides, but these mutants showed phenotypes comparable to those of mutants selected by dyes. All mutants showed changes in the promoter region of norA, but these were distinct from this region of the clinical isolates. Still, none of the in vitro mutants displayed fitness defects in a killing assay in Galleria mellonella larvae. In conclusion, our data provide an in-depth comparative overview on efflux in S. aureus mutants and clinical isolates, showing also that plasmid-encoded efflux pumps did not affect bactericidal activity of biocides. In addition, current in vitro tests appear not to be suitable for predicting levels of resistance that are clinically relevant. PMID:23669380

  11. High performance ammonium nitrate propellant

    NASA Technical Reports Server (NTRS)

    Anderson, F. A. (inventor)

    1979-01-01

    A high performance propellant having greatly reduced hydrogen chloride emission is presented. It is comprised of: (1) a minor amount of hydrocarbon binder (10-15%), (2) at least 85% solids including ammonium nitrate as the primary oxidizer (about 40% to 70%), (3) a significant amount (5-25%) powdered metal fuel, such as aluminum, (4) a small amount (5-25%) of ammonium perchlorate as a supplementary oxidizer, and (5) optionally a small amount (0-20%) of a nitramine.

  12. Effects of Benzalkonium Chloride on Planktonic Growth and Biofilm Formation by Animal Bacterial Pathogens

    PubMed Central

    Ebrahimi, Azizollah; Hemati, Majid; Shabanpour, Ziba; Habibian Dehkordi, Saeed; Bahadoran, Shahab; Lotfalian, Sharareh; Khubani, Shahin

    2015-01-01

    Background: Resistance toward quaternary ammonium compounds (QACs) is widespread among a diverse range of microorganisms and is facilitated by several mechanisms such as biofilm formation. Objectives: In this study, the effects of benzalkonium chloride on planktonic growth and biofilm formation by some field isolates of animal bacterial pathogens were investigated. Materials and Methods: Forty clinical isolates of Escherichia coli, Salmonella serotypes, Staphylococcus aureus and Streptococcus agalactiae (10 isolates of each) were examined for effects of benzalkonium chloride on biofilm formation and planktonic growth using microtiter plates. For all the examined strains in the presence of benzalkonium chloride, biofilm development and planktonic growth were affected at the same concentrations of disinfectant. Results: The means of strains growth increase after the minimal inhibitory concentration (MIC) were significant in all the bacteria (except for E. coli in 1/32 and S. agalactiae in of 1/8 MIC). Biofilm formation increased with decrease of antiseptics concentration; a significant increase was found in all the samples. The most turbidity related to S. aureus and the least to Salmonella. Conclusions: Bacterial resistance against quaternary ammonium compounds is increasing which can increase the bacterial biofilm formation. PMID:25793094

  13. Synthesis and application of a quaternary phosphonium polymer coagulant to avoid N-nitrosamine formation.

    PubMed

    Zeng, Teng; Pignatello, Joseph J; Li, Russell Jingxian; Mitch, William A

    2014-11-18

    Quaternary ammonium cationic polymers, such as poly(diallyldimethylammonium chloride) (polyDADMAC) are widely used for coagulating and removing negatively charged particles and dissolved organic matter (DOM) from drinking water. Their use, however, has been linked to the formation of carcinogenic N-nitrosamines as byproducts during chloramine-based drinking water disinfection. In this study, a novel quaternary phosphonium cationic polymer, poly(diallyldiethylphosphonium chloride) (polyDADEPC), was synthesized such that the quaternary nitrogen atom of polyDADMAC was substituted with a phosphorus atom. Formation potential tests revealed that even under strong nitrosation conditions, polyDADEPC and related lower-order P-based compounds formed oxygenated and not nitrosated products. Bench-scale jar tests using three different source waters further demonstrated that polyDADEPC achieved coagulation performance comparable to commercial polyDADMACs for particle and DOM removals within the typical dose range used for drinking water treatment. This work highlights the potential use of a phosphonium coagulant polymer, polyDADEPC, as a viable alternative to polyDADMAC to avoid nitrosated byproduct formation during chloramination. PMID:25322258

  14. Biodegradation of rocket propellant waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqvi, S. M. Z.; Latif, A.

    1975-01-01

    The short term effects of ammonium perchlorate on selected organisms were studied. A long term experiment was also designed to assess the changes incurred by ammonium perchlorate on the nitrogen and chloride contents of soil within a period of 3 years. In addition, an attempt was made to produce methane gas from anaerobic fermentation of the aquatic weed, Alternanthera philoxeroides.

  15. Quaternary investigation

    SciTech Connect

    Stieve, A.

    1991-05-15

    The primary purpose of the Quaternary investigation is to provide information on the location and age of Quaternary deposits for use in evaluating the presence or absence of neotectonic deformation or paleoliquefaction features within the Savannah River Site (SRS) region. The investigation will provide a basis for evaluating the potential for capable faults and associated deformation in the SRS vicinity. Particular attention will be paid to the Pen Branch fault.

  16. Liquid chromatography of hydrocarbonaeous quaternary amines on cyclodextrin bonded silica

    USGS Publications Warehouse

    Abidi, S.L.

    1986-01-01

    Mixtures of n-alkylbenzyldimethylammonium chloride (ABDAC) were resolved into homologous components by high-performance liquid chromatography (HPLC) with a cyclodextrin-bonded silica stationary phase. With a few exceptions, results from this study are similar to those obtained from traditional reversed-phase HPLC. It was found that the presence of electrolytes in aqueous mobile phases is not a critical factor in determining the success of HPLC separation. Under normal HPLC conditions, a mobile phase consisting of either methanol–water (50:50) or acetonitrile–water (30:70) was employed for obtaining adequate resolution of the quaternary ammonium mixtures. Although the percent organic modifier–water profiles were similar to those in previous studies with these compounds, resolution (R) and selectivity (?) parameters were found to be quite susceptible to changes in the mobile phase solvent composition. The retention behavior of the cationic analytes in the homologous series is consistent with the hydrophobic-interaction concept proposed for the retention mechanism via dominant inclusion complex formation. Several electrolytes were chosen for a study of the counter ion effect on the chromatographic characteristics of ABDAC components. Among the electrolytes examined, the perchlorate ion was found most likely to act as an ion-pairing counter ion for ammonium cations in the HPLC system studied. A correlation study established linear relationships between the chain length of ABDAC and the logarithmic capacity factor (k2). The analytical utility of the HPLC method was demonstrated by the analysis of various unknown mixtures.

  17. Ammonium acetate

    Integrated Risk Information System (IRIS)

    Ammonium acetate ; CASRN 631 - 61 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  18. Ammonium sulfamate

    Integrated Risk Information System (IRIS)

    Ammonium sulfamate ; CASRN 7773 - 06 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  19. Ammonium methacrylate

    Integrated Risk Information System (IRIS)

    Ammonium methacrylate ; CASRN 16325 - 47 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  20. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...use: (1) The ingredient is used as a dough strengthener as defined in § 170.3(o)(6) of this chapter; a flavor enhancer as defined in § 170.3(o)(11) of this chapter; a leavening agent as defined in § 170.3(o)(17) of this...

  1. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...use: (1) The ingredient is used as a dough strengthener as defined in § 170.3(o)(6) of this chapter; a flavor enhancer as defined in § 170.3(o)(11) of this chapter; a leavening agent as defined in § 170.3(o)(17) of this...

  2. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...use: (1) The ingredient is used as a dough strengthener as defined in § 170.3(o)(6) of this chapter; a flavor enhancer as defined in § 170.3(o)(11) of this chapter; a leavening agent as defined in § 170.3(o)(17) of this...

  3. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...use: (1) The ingredient is used as a dough strengthener as defined in § 170.3(o)(6) of this chapter; a flavor enhancer as defined in § 170.3(o)(11) of this chapter; a leavening agent as defined in § 170.3(o)(17) of this...

  4. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...use: (1) The ingredient is used as a dough strengthener as defined in § 170.3(o)(6) of this chapter; a flavor enhancer as defined in § 170.3(o)(11) of this chapter; a leavening agent as defined in § 170.3(o)(17) of this...

  5. Contaminants of Emerging Concern Strategy Update

    E-print Network

    Phenols (pro bono) #12;Quaternary Ammonium Compounds (pro bono) Benzalkonium chloride (C12) & Ditallow dimethyl ammonium chloride (C18) Bruce Brownawell Stony Brook University #12;Sharing expertise, learning

  6. Supporting Information for: Ammonium Bicarbonate Transport in Anion Exchange Membranes

    E-print Network

    S1 Supporting Information for: Ammonium Bicarbonate Transport in Anion Exchange Membranes was measured by first equilibrating the polymer film in the desired solution [e.g., DI water, 0.5 mol/L sodium chloride (NaCl), or 0.5 mol/L ammonium bicarbonate (AmB)]. Films were allowed to equilibrate

  7. Biodegradation of benzalkonium chlorides singly and in mixtures by a Pseudomonas sp. isolated from returned activated sludge.

    PubMed

    Khan, Adnan Hossain; Topp, Edward; Scott, Andrew; Sumarah, Mark; Macfie, Sheila M; Ray, Madhumita B

    2015-12-15

    Bactericidal cationic surfactants such as quaternary ammonium compounds (QACs) are widely detected in the environment, and found at mgkg(-1) concentrations in biosolids. Although individual QACs are amenable to biodegradation, it is possible that persistence is increased for mixtures of QACs with varying structure. The present study evaluated the biodegradation of benzyl dimethyl dodecyl ammonium chloride (BDDA) singly and in the presence of benzyl dimethyl tetradecyl ammonium chloride (BDTA) using Pseudomonas sp., isolated from returned activated sludge. Growth was evaluated, as was biodegradation using (14)C and HPLC-MS methods. BDTA was more toxic to growth of Pseudomonas sp. compared to BDDA, and BDTA inhibited BDDA biodegradation. The benzyl ring of [U-(14)C-benzyl] BDDA was readily and completely mineralized. The detection of the transformation products benzyl methyl amine and dodecyl dimethyl amine in spent culture liquid was consistent with literature. Overall, this study demonstrates the antagonistic effect of interactions on biodegradation of two widely used QACs suggesting further investigation on the degradation of mixture of QACs in wastewater effluents and biosolids. PMID:26277347

  8. Crystal structure of the inclusion complex 25-benzo­ylmeth­oxy-5,11,17,23-tetra-tert-butyl-26,27,28-trihy­droxy-2,8,14,20-tetra­thia­calix[4]arene–tetra­ethyl­ammonium chloride (1/1)

    PubMed Central

    Akkurt, Mehmet; Jasinski, Jerry P.; Mohamed, Shaaban K.; Omran, Omran A.; Albayati, Mustafa R.

    2015-01-01

    The asymmetric unit of the title compound, C48H54O5S4·N(C2H5)4 +·Cl?, contains two tetra-tert-butyl-[(benzo­yl)meth­oxy]-trihy­droxy-tetra­thia­calix[4]arene mol­ecules, two tetra­ethyl­ammonium cations and two chloride anions. The two calixarene molecules in the asymmetric unit each display a cone conformation. There are no significant differences between the two independent molecules. The guest species do not sit within the calixarene ‘buckets’. In the crystal, extensive O—H?O, O—H?S and O—H?Cl hydrogen bonds and weak C—H?O, C—H?S and C—H?Cl inter­actions link the thia­calixarene mol­ecules, tetra­ethyl­ammonium cations and chloride anions, forming a three-dimensional network encompassing channels running parallel to the a-axis direction. The structure contains a solvent-accessible void of 76?(3)?Å3, but no solvent mol­ecule could reasonably be located. The crystal studied was an inversion twin with a 0.57?(8):0.43?(8) domain ratio. PMID:26594550

  9. Crystal structure of the inclusion complex 25-benzo-ylmeth-oxy-5,11,17,23-tetra-tert-butyl-26,27,28-trihy-droxy-2,8,14,20-tetra-thia-calix[4]arene-tetra-ethyl-ammonium chloride (1/1).

    PubMed

    Akkurt, Mehmet; Jasinski, Jerry P; Mohamed, Shaaban K; Omran, Omran A; Albayati, Mustafa R

    2015-11-01

    The asymmetric unit of the title compound, C48H54O5S4·N(C2H5)4 (+)·Cl(-), contains two tetra-tert-butyl-[(benzo-yl)meth-oxy]-trihy-droxy-tetra-thia-calix[4]arene mol-ecules, two tetra-ethyl-ammonium cations and two chloride anions. The two calixarene molecules in the asymmetric unit each display a cone conformation. There are no significant differences between the two independent molecules. The guest species do not sit within the calixarene 'buckets'. In the crystal, extensive O-H?O, O-H?S and O-H?Cl hydrogen bonds and weak C-H?O, C-H?S and C-H?Cl inter-actions link the thia-calixarene mol-ecules, tetra-ethyl-ammonium cations and chloride anions, forming a three-dimensional network encompassing channels running parallel to the a-axis direction. The structure contains a solvent-accessible void of 76?(3)?Å(3), but no solvent mol-ecule could reasonably be located. The crystal studied was an inversion twin with a 0.57?(8):0.43?(8) domain ratio. PMID:26594550

  10. A hybridization approach to efficient TiO2 photodegradation of aqueous benzalkonium chloride.

    PubMed

    Suchithra, Padmajan Sasikala; Carleer, Robert; Ananthakumar, Solaippan; Yperman, Jan

    2015-08-15

    TiO2 get positively charged upon UV-irradiation and repel the cationic pollutants away from the surface. Hybridization of AC onto TiO2 (ACT) tends catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic pollutants. The photodegradation of benzalkonium chloride (BKC), a quaternary ammonium surfactant and a pharmaceutical, is investigated with ACT. The surface charge of the catalyst in surfactant and non-surfactant aqueous dispersion under UV-irradiation is investigated and explained. The anomalous increase in COD values at the beginning of BKC-photodegradation is explained. The intermediate products formed are identified in both solution and solid phase. Trace amount of dodecane remained adsorbed on the catalyst surface after 1h UV-irradiation, but complete mineralization of BKC is achieved with 2h UV-irradiation. We propose that BKC photodegradation starts by central fission of benzyl CN bond followed by dealkylation, and demethylation steps. PMID:25855569

  11. Vinyl Chloride

    Cancer.gov

    Vinyl chloride is a colorless gas that burns easily. It does not occur naturally and must be produced industrially for its commercial uses. Vinyl chloride is used primarily to make polyvinyl chloride (PVC); PVC is used to make a variety of plastic products, including pipes, wire and cable coatings, and packaging materials. Vinyl chloride is also produced as a combustion product in tobacco smoke.

  12. Quaternary and Geomorphology.

    ERIC Educational Resources Information Center

    Andrews, J. T.; Graf, W. L.

    1983-01-01

    Highlights conferences and meetings of organizations involved with quaternary geology and geomorphology, including International Union of Quaternary Research Conference held in Moscow. The impetus of a revision of "The Quaternary of the United States" resulted from this conference. Includes activities/aims of "Friends of the Pleistocene"…

  13. Listeria monocytogenes strains selected on ciprofloxacin or the disinfectant benzalkonium chloride exhibit reduced susceptibility to ciprofloxacin, gentamicin, benzalkonium chloride, and other toxic compounds.

    PubMed

    Rakic-Martinez, Mira; Drevets, Douglas A; Dutta, Vikrant; Katic, Vera; Kathariou, Sophia

    2011-12-01

    Listeria monocytogenes is a leading agent for severe food-borne illness and death in the United States and other nations. Even though drug resistance has not yet threatened therapeutic interventions for listeriosis, selective pressure associated with exposure to antibiotics and disinfectants may result in reduced susceptibility to these agents. In this study, selection of several L. monocytogenes strains on either ciprofloxacin (2 ?g/ml) or the quaternary ammonium disinfectant benzalkonium chloride (BC; 10 ?g/ml) led to derivatives with increased MICs not only to these agents but also to several other toxic compounds, including gentamicin, the dye ethidium bromide, and the chemotherapeutic drug tetraphenylphosphonium chloride. The spectrum of compounds to which these derivatives exhibited reduced susceptibility was the same regardless of whether they were selected on ciprofloxacin or on BC. Inclusion of strains harboring the large plasmid pLM80 revealed that MICs to ciprofloxacin and gentamicin did not differ between the parental and plasmid-cured strains. However, ciprofloxacin-selected derivatives of pLM80-harboring strains had higher MICs than those derived from the plasmid-cured strains. Susceptibility to the antimicrobials was partially restored in the presence of the potent efflux inhibitor reserpine. Taken together, these data suggest that mutations in efflux systems are responsible for the multidrug resistance phenotype of strains selected on ciprofloxacin or BC. PMID:22003016

  14. Hygroscopic and phase separation properties of ammonium sulfate/organics/water ternary solutions

    E-print Network

    Zawadowicz, Maria Anna

    Atmospheric aerosol particles are often partially or completely composed of inorganic salts, such as ammonium sulfate and sodium chloride, and therefore exhibit hygroscopic properties. Many inorganic salts have well-defined ...

  15. NEW QUATERNARY AMMONIUM ION REAGENTS FROM UREA FOR FABRIC TREATMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, we showed a one step conversion of urea to tertiary amines in water (J. Org. Chem., 2000, 65, 9234-9237). Of these, we used triallylamine to quaternize PEG, PPG, and aryl bromides (Figure 1). One and two-dimensional NMR and chemical ionization mass spectrometries were used to characteriz...

  16. Quaternary ammonium borohydride adsorption in mesoporous silicate MCM-48

    SciTech Connect

    Wolverton, Michael J; Daemen, Luke L; Hartl, Monika A

    2010-01-01

    Inorganic borohydrides have a high gravimetric hydrogen density but release H2 only under energetically unfavorable conditions. Surface chemistry may help in lowering thermodynamic barriers, but inclusion of inorganic borohydrides in porous silica materials has proved hitherto difficult or impossible. We show that borohydrides with a large organic cation are readily adsorbed inside mesoporous silicates, particularly after surface treatment. Thermal analysis reveals that the decomposition thermodynamics of tetraalkylammonium borohydrides are substantially affected by inclusion in MCM-48. Inelastic neutron scattering (INS) data show that the compounds adsorb on the silica surface. Evidence of pore loading is supplemented by DSC/TGA, XRD, FTIR, and BET isotherm measurements. Mass spectrometry shows significant hydrogen release at lower temperature from adsorbed borohydrides in comparison with the bulk borohydrides. INS data measured for partially decomposed samples indicates that the decomposition of the cation and anion is likely simultaneous. Additionally, these data confirm the formation of Si-H bonds on the silica surface upon decomposition of adsorbed tetramethylammonium borohydride.

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

    SciTech Connect

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

    2013-03-01

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

  18. Ammonium hydroxide poisoning

    MedlinePLUS

    ... cleaners such as flooring strippers, brick cleaners, and cements. Ammonium hydroxide can also release ammonia gas into ... Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2004:chap 200. Wax ...

  19. Ammonium nitrate explosive systems

    DOEpatents

    Stinecipher, Mary M. (Los Alamos, NM); Coburn, Michael D. (Los Alamos, NM)

    1981-01-01

    Novel explosives which comprise mixtures of ammonium nitrate and an ammonium salt of a nitroazole in desired ratios are disclosed. A preferred nitroazole is 3,5-dinitro-1,2,4-triazole. The explosive and physical properties of these explosives may readily be varied by the addition of other explosives and oxidizers. Certain of these mixtures have been found to act as ideal explosives.

  20. Noncovalent Complexation of Monoamine Neurotransmitters and Related Ammonium Ions by Tetramethoxy Tetraglucosylcalix[4]arene

    NASA Astrophysics Data System (ADS)

    Torvinen, Mika; Kalenius, Elina; Sansone, Francesco; Casnati, Alessandro; Jänis, Janne

    2012-02-01

    The noncovalent complexation of monoamine neurotransmitters and related ammonium and quaternary ammonium ions by a conformationally flexible tetramethoxy glucosylcalix[4]arene was studied by electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. The glucosylcalixarene exhibited highest binding affinity towards serotonin, norepinephrine, epinephrine, and dopamine. Structural properties of the guests, such as the number, location, and type of hydrogen bonding groups, length of the alkyl spacer between the ammonium head-group and the aromatic ring structure, and the degree of nitrogen substitution affected the complexation. Competition experiments and guest-exchange reactions indicated that the hydroxyl groups of guests participate in intermolecular hydrogen bonding with the glucocalixarene.

  1. Phase Transitions and Phase Miscibility of Mixed Particles of Ammonium Sulfate, Toluene-Derived Secondary Organic Material,

    E-print Network

    in atmospheric particles, such as sodium chloride and ammonium sulfate, have been significantly studied.6 neither the ERH() nor DRH() curves, implying an absence of kinetic effects on the observations over

  2. Hydrogen chloride

    Integrated Risk Information System (IRIS)

    Hydrogen chloride ; CASRN 7647 - 01 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  3. Ethyl chloride

    Integrated Risk Information System (IRIS)

    Ethyl chloride ; CASRN 75 - 00 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  4. Mepiquat chloride

    Integrated Risk Information System (IRIS)

    Mepiquat chloride ; CASRN 24307 - 26 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  5. Allyl chloride

    Integrated Risk Information System (IRIS)

    Allyl chloride ; CASRN 107 - 05 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  6. Acetyl chloride

    Integrated Risk Information System (IRIS)

    Acetyl chloride ; CASRN 75 - 36 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  7. Benzyl chloride

    Integrated Risk Information System (IRIS)

    Benzyl chloride ; CASRN 100 - 44 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  8. Vinyl chloride

    Integrated Risk Information System (IRIS)

    EPA / 635R - 00 / 004 TOXICOLOGICAL REVIEW OF VINYL CHLORIDE ( CAS No . 75 - 01 - 4 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) May 2000 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been reviewed in accordance with U.S

  9. Methyl chloride

    Integrated Risk Information System (IRIS)

    EPA / 635 / R01 / 003 TOXICOLOGICAL REVIEW OF METHYL CHLORIDE ( CAS No . 74 - 87 - 3 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) June 2001 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been reviewed in accordance with U.

  10. Impact of chain length on antibacterial activity and hemocompatibility of quaternary N-alkyl and n,n-dialkyl chitosan derivatives.

    PubMed

    Sahariah, Priyanka; Benediktssdóttir, Berglind E; Hjálmarsdóttir, Martha Á; Sigurjonsson, Olafur E; Sørensen, Kasper K; Thygesen, Mikkel B; Jensen, Knud J; Másson, Már

    2015-05-11

    A highly efficient method for chemical modification of chitosan biopolymers by reductive amination to yield N,N-dialkyl chitosan derivatives was developed. The use of 3,6-O-di-tert-butyldimethylsilylchitosan as a precursor enabled the first 100% disubstitution of the amino groups with long alkyl chains. The corresponding mono N-alkyl derivatives were also synthesized, and all the alkyl compounds were then quaternized using an optimized procedure. These well-defined derivatives were studied for antibacterial activity against Gram positive S. aureus, E. faecalis, and Gram negative E. coli, P. aeruginosa, which could be correlated to the length of the alkyl chain, but the order was dependent on the bacterial strain. Toxicity against human red blood cells and human epithelial Caco-2 cells was found to be proportional to the length of the alkyl chain. The most active chitosan derivatives were found to be more selective for killing bacteria than the quaternary ammonium disinfectants cetylpyridinium chloride and benzalkonium chloride, as well as the antimicrobial peptides melittin and LL-37. PMID:25830631

  11. Poly-N-acetylglucosamine matrix polysaccharide impedes fluid convection and transport of the cationic surfactant cetylpyridinium chloride through bacterial biofilms.

    PubMed

    Ganeshnarayan, Krishnaraj; Shah, Suhagi M; Libera, Matthew R; Santostefano, Anthony; Kaplan, Jeffrey B

    2009-03-01

    Biofilms are composed of bacterial cells encased in a self-synthesized, extracellular polymeric matrix. Poly-beta(1,6)-N-acetyl-d-glucosamine (PNAG) is a major biofilm matrix component in phylogenetically diverse bacteria. In this study we investigated the physical and chemical properties of the PNAG matrix in biofilms produced in vitro by the gram-negative porcine respiratory pathogen Actinobacillus pleuropneumoniae and the gram-positive device-associated pathogen Staphylococcus epidermidis. The effect of PNAG on bulk fluid flow was determined by measuring the rate of fluid convection through biofilms cultured in centrifugal filter devices. The rate of fluid convection was significantly higher in biofilms cultured in the presence of the PNAG-degrading enzyme dispersin B than in biofilms cultured without the enzyme, indicating that PNAG decreases bulk fluid flow. PNAG also blocked transport of the quaternary ammonium compound cetylpyridinium chloride (CPC) through the biofilms. Binding of CPC to biofilms further impeded fluid convection and blocked transport of the azo dye Allura red. Bioactive CPC was efficiently eluted from biofilms by treatment with 1 M sodium chloride. Taken together, these findings suggest that CPC reacts directly with the PNAG matrix and alters its physical and chemical properties. Our results indicate that PNAG plays an important role in controlling the physiological state of biofilms and may contribute to additional biofilm-associated processes such as biocide resistance. PMID:19114520

  12. 70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM NITRATE IN STORAGE. APRIL 18, 1919. - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  13. The toxicity of ammonia/ammonium to the vermifiltration wastewater treatment process.

    PubMed

    Hughes, R J; Nair, J; Ho, G

    2008-01-01

    This study was undertaken to assess the toxicity of ammonia/ammonium to key species within the vermifiltration process. The key species, the earthworm Eisenia fetida, was subjected to a series of tests in solid phase mesocosms and full-scale units. The solid phase tests showed a relatively low toxicity to ammonium with ammonium chloride having an LC50 for ammonium of 1.49 g/kg. Ammonium sulfate did not show an effect on mortality at 2 g/kg ammonium. The full-scale units showed that ammonia hydroxide can change the pH and concentration of ammonia in wastewater and while it caused some mortality to the worms its overall affect on system functioning was minimal with no significant difference in terms of worm survival found between treatments. The affect on nitrifying bacteria was also minimal with no linear trend shown with ammonia concentration. PMID:18845859

  14. Glufosinate-ammonium

    Integrated Risk Information System (IRIS)

    Glufosinate - ammonium ; CASRN 77182 - 82 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  15. Removal of ammonium from municipal landfill leachate using natural zeolites.

    PubMed

    Ye, Zhihong; Wang, Jiawen; Sun, Lingyu; Zhang, Daobin; Zhang, Hui

    2015-12-01

    Ammonium ion-exchange performance of the natural zeolite was investigated in both batch and column studies. The effects of zeolite dosage, contact time, stirring speed and pH on ammonium removal were investigated in batch experiments. The result showed that ammonium removal efficiency increased with an increase in zeolite dosage from 25 to 150 g/L, and an increase in stirring speed from 200 to 250 r/min. But further increase in zeolite dosage and stirring speed would result in an unpronounced increase of ammonium removal. The optimal pH for the removal of ammonium was found as 7.1. In the column studies, the effect of flow rate was investigated, and the total ammonium removal percentage during 180 min operation time decreased with the flow rate though the ion-exchange capacity varied to a very small extent with the flow rate ranging from 4 to 9 mL/min. The spent zeolite was regenerated by sodium chloride solution and the ammonia removal capacity of zeolite changed little or even increased after three regeneration cycles. PMID:26510611

  16. Experimental study of directional solidification of aqueous ammonium chloride solution

    NASA Technical Reports Server (NTRS)

    Chen, C. F.; Chen, Falin

    1991-01-01

    Directional solidification experiments have been carried out using the analog casting system of NH4Cl-H2O solution by cooling it from below with a constant-temperature surface ranging from -31.5 C to +11.9 C. The NH4Cl concentration was 26 percent in all solutions, with a liquidus temperature of 15 C. It was found that finger convection occurred in the fluid region just above the mushy layer in all experiments. Plume convection with associated chimneys in the mush occurred in experiments with bottom temperatures as high as +11.0 C. However, when the bottom temperature was raised to +11.9 C, no plume convection was observed, although finger convection continued as usual. A method has been devised to determine the porosity of the mush by computed tomography. Using the mean value of the porosity across the mush layer and the permeability calculated by the Kozeny-Carman relationship, the critical solute Rayleigh number across the mush layer for onset of plume convection was estimated to be between 200 and 250.

  17. In vivo stability and distribution of (/sup 131/I)iodomethyl trimethylammonium chloride: concise communication

    SciTech Connect

    Huang, C.C.; Friedman, A.M.; Rayudu, G.V.S.; Clark, P.; Fordham, E.W.

    1980-07-01

    (/sup 131/I)iodomethyl trimethylammonium chloride (I-131 TMA) was prepared by the isotope-exchange reaction of diiodomethane with Na/sup 131/I, followed by reaction with trimethylamine. A specific activity of 20 ..mu..Ci/mg was obtained. Tissue distributions following intravenous injection of I-131 TMA in mice showed that between 10 min and 2 h, the highest accumulations of radioactivity were in the urine, kidney, and heart. The uptake of this compound in the heart was very rapid, and the levels of radioactivity remained fairly high up to 2 h. At 10, 30, 60, and 120 min the heart-to-blood ratios were, respectively, 10.2, 7.7, 8.3, and 9.6. Thyroid uptake of this compound in the rats and analysis of urine samples of the mouse indicated no extensive deiodination of the compound in vivo. These results show that this compound does have potential for use in myocardial imaging. In addition, its stability in vivo makes it very useful for the radiolabeling of compounds containing quaternary ammonium moieties.

  18. Hydrothermal synthesis of ammonium illite

    USGS Publications Warehouse

    Sucha, V.; Elsass, F.; Eberl, D.D.; Kuchta, L'.; Madejova, J.; Gates, W.P.; Komadel, P.

    1998-01-01

    Synthetic gel and glass of illitic composition, natural kaolinite, and mixed-layer illite-smectite were used as starting materials for hydrothermal synthesis of ammonium illite. Ammonium illite was prepared from synthetic gel by hydrothermal treatment at 300??C. The onset of crystallization began within 3 h, and well-crystallized ammonium illite appeared at 24 h. Increasing reaction time (up to four weeks) led to many illite layers per crystal. In the presence of equivalent proportions of potassium and ammonium, the gel was transformed to illite with equimolar contents of K and NH4. In contrast, synthesis using glass under the same conditions resulted in a mixture of mixed-layer ammonium illite-smectite with large expandability and discrete illite. Hydrothermal treatments of the fine fractions of natural kaolinite and illite-smectite produced ammonium illite from kaolinite but the illite-smectite remained unchanged.

  19. Effect of impurities on crystal growth rate of ammonium pentaborate

    NASA Astrophysics Data System (ADS)

    ?ahin, Ö.; Özdemir, M.; Genli, N.

    2004-01-01

    The effect of sodium chloride, borax and boric acid of different concentrations on the growth rate of ammonium pentaborate octahydrate crystals (APBO) was measured and was found to depend on supersaturation in a fluidized bed crystallizer. The presence of impurities in APBO solution increases the growth rate compared with growth from pure solution. It was found that the presence of sodium chloride, borax and boric acid decreases the reaction rate constant kr, while it increases the mass-transfer coefficient, K, of APBO crystals. In pure aqueous solution, the crystal growth rate of APBO is mainly controlled by diffusion. However, both diffusion and integration steps affect the growth rate of APBO crystals in the presence of sodium chloride, borax and boric acid. The mass-transfer coefficient, K, reaction rate constant, kr and reaction order, r were calculated from general mass-transfer equation by using genetic algorithm method making no assumption.

  20. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions...126.28 Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...

  1. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions...126.28 Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...

  2. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions...126.28 Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...

  3. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions...126.28 Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...

  4. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions...126.28 Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...

  5. Effects of different chloride precursors on crystal growth of lead halide perovskites

    NASA Astrophysics Data System (ADS)

    Murugan, Vigneshwaran; Ogomi, Yuhei; Pandey, Shyam S.; Toyoda, Taro; Shen, Qing; Hayase, Shuzi

    2015-12-01

    The optimized quantity and nature of a chloride precursor used for the formation of large perovskite crystals with minimal disorder were explored. The effect of the alkyl chain length of an alkyl ammonium chloride precursor on the crystal growth of CH3NH3PbI3 was systematically investigated. It was found that the addition of ethyl ammonium chloride (EACl) increased the crystal size, which is almost twice (88 nm) the size of standard perovskite crystals (47 nm) having a preferential orientation towards the (110) plane. Photoacoustic studies demonstrated that the disorder in the perovskite crystals was highly reduced by the addition of the EACl precursor.

  6. 76 FR 11273 - Ammonium Nitrate From Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ...Second Review)] Ammonium Nitrate From Russia AGENCY: United States International Trade...investigation on ammonium nitrate from Russia...investigation on ammonium nitrate from Russia would be likely to lead to...

  7. 76 FR 47238 - Ammonium Nitrate From Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ...Second Review] Ammonium Nitrate From Russia Determination On the basis of the record...antidumping duty order on ammonium nitrate from Russia would be likely to lead to continuation...2011), entitled Ammonium Nitrate from Russia: Investigation No....

  8. 76 FR 70366 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ...DHS-2008-0076] RIN 1601-AA52 Ammonium Nitrate Security Program AGENCY: National Protection...rulemaking (NPRM), entitled ``Ammonium Nitrate Security Program,'' which was published...62311). Under the proposed Ammonium Nitrate Security Program, the DHS will...

  9. AMBIENT AMMONIA AND AMMONIUM AEROSOL ACROSS A REGION OF VARIABLE AMMONIA EMISSION DENSITY

    EPA Science Inventory

    The paper presents one year of ambient ammonia (NH3), ammonium (NH4+), hydrochloric acid (HCI), chloride (CI¯), nitric acid (HNO3), nitrate (NO3¯), nitrous acid (HONO), sulfur dioxide (SO2), and sulfate (SO4

  10. Prolonged exposure of mixed aerobic cultures to low temperature and benzalkonium chloride affect the rate and extent of nitrification.

    PubMed

    Yang, Jeongwoo; Tezel, Ulas; Li, Kexun; Pavlostathis, Spyros G

    2015-03-01

    The combined effect of benzalkonium chloride (BAC) and prolonged exposure to low temperature on nitrification was investigated. Ammonia oxidation at 22-24°C by an enriched nitrifying culture was inhibited at increasing BAC concentrations and ceased at 15 mg BAC/L. The non-competitive inhibition coefficient was 1.5±0.9 mg BAC/L. Nitrification tests were conducted without and with BAC at 5mg/L using an aerobic, mixed heterotrophic/nitrifying culture maintained at a temperature range of 24-10°C. Maintaining this culture at 10°C for over one month in the absence of BAC, resulted in slower nitrification kinetics compared to those measured when the culture was first exposed to 10°C. BAC was degraded by the heterotrophic population, but its degradation rate decreased significantly as the culture temperature decreased to 10°C. These results confirm the negative impact of quaternary ammonium compounds on the nitrification process, which is further exacerbated by prolonged, low temperature conditions. PMID:25544497

  11. Adsorption of ammonium ion by coconut shell-activated carbon from aqueous solution: kinetic, isotherm, and thermodynamic studies.

    PubMed

    Boopathy, Ramasamy; Karthikeyan, Sekar; Mandal, Asit Baran; Sekaran, Ganesan

    2013-01-01

    Ammonium ions are one of the most encountered nitrogen species in polluted water bodies. High level of ammonium ion in aqueous solution imparts unpleasant taste and odor problems, which can interfere with the life of aquatics and human population when discharged. Many chemical methods are developed and being used for removal of ammonium ion from aqueous solution. Among various techniques, adsorption was found to be the most feasible and environmentally friendly with the use of natural-activated adsorbents. Hence, in this study, coconut shell-activated carbon (CSAC) was prepared and used for the removal of ammonium ion by adsorption techniques. Ammonium chloride (analytical grade) was purchased from Merck Chemicals for adsorption studies. The CSAC was used to adsorb ammonium ions under stirring at 100 rpm, using orbital shaker in batch experiments. The concentration of ammonium ion was estimated by ammonia distillate, using a Buchi distillation unit. The influence of process parameters such as pH, temperature, and contact time was studied for adsorption of ammonium ion, and kinetic, isotherm models were validated to understand the mechanism of adsorption of ammonium ion by CSAC. Thermodynamic properties such as ?G, ?H, and ?S were determined for the ammonium adsorption, using van't Hoff equation. Further, the adsorption of ammonium ion was confirmed through instrumental analyses such as SEM, XRD, and FTIR. The optimum conditions for the effective adsorption of ammonium ion onto CSAC were found to be pH 9.0, temperature 283 K, and contact time 120 min. The experimental data was best followed by pseudosecond order equation, and the adsorption isotherm model obeyed the Freundlich isotherm. This explains the ammonium ion adsorption onto CSAC which was a multilayer adsorption with intraparticle diffusion. Negative enthalpy confirmed that this adsorption process was exothermic. The instrumental analyses confirmed the adsorption of ammonium ion onto CSAC. PMID:22562341

  12. Global modeling of nitrate and ammonium aerosols using EQSAM3

    NASA Astrophysics Data System (ADS)

    Xu, L.; Penner, J. E.

    2009-12-01

    Atmospheric aerosols, particles suspending in air, are important as they affect human health, air quality, and visibility as well as climate. Sulfate, nitrate, ammonium, chloride and sodium are among the most important inorganic aerosol species in the atmosphere. These compounds are hygroscopic and absorb water under almost all ambient environmental conditions. The uptake of water alters the aerosol size, and causes water to become the constituent with the largest atmospheric aerosol mass, especially when the aerosols grow into fog, haze or clouds. Furthermore, several global model studies have demonstrated that rapid increases in nitrogen emissions could produce enough nitrate in aerosols to offset the expected decline in sulfate forcing by 2100 for the extreme IPCC A2 scenario (Bauer et al., 2007). Although nitrate and ammonium were identified as significant anthropogenic sources of aerosols by a number of modeling studies, most global aerosol models still exclude ammonium-nitrate when the direct aerosol forcing is studied. In this study, the computationally efficient equilibrium model, EQSAM3, is incorporated into the UMICH-IMPACT-nitrate model using the hybrid dynamical solution method (Feng and Penner, 2007). The partitioning of nitrate and ammonium along with the corresponding water uptake is evaluated by comparing the model to the EQUISOLVE II method used in Feng and Penner (2007). The model is also evaluated by comparison with the AERONET data base and satellite-based aerosol optical depths.

  13. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food... Specific Substances Affirmed as GRAS § 184.1137 Ammonium carbonate. (a) Ammonium carbonate ((NH4)2CO3,...

  14. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food... Specific Substances Affirmed as GRAS § 184.1137 Ammonium carbonate. (a) Ammonium carbonate ((NH4)2CO3,...

  15. Treatment of ammonium-rich swine waste in modified porphyritic andesite fixed-bed anaerobic bioreactor.

    PubMed

    Wang, Qinghong; Yang, Yingnan; Li, Dawei; Feng, Chuanping; Zhang, Zhenya

    2012-05-01

    In this study, a modified porphyritic andesite (WRS) was developed as ammonium adsorbent and bed material for the anaerobic digestion of ammonium-rich swine waste. The performance in bioreactors with modified WRS, natural WRS, calcium chloride and no additives was investigated. The bioreactor with modified WRS exhibited the best performance, with start-up time on the 7th day, methane yield of 359.71 ml/g-VS, and COD removal of 67.99% during all 44 days of the experiment at 35°C. The effective ammonium adsorption and essential ions dissociation for microorganisms by modified WRS, as well as the immobilization of microbial on the surface of the modified WRS play a great role on the high efficiency anaerobic digestion of ammonium-rich swine waste. PMID:22366608

  16. CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT WITH SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  17. Chloride - urine test

    MedlinePLUS

    The urine chloride test measures the amount of chloride in a certain volume of urine. ... After you provide a urine sample, it is tested in the lab. If needed, the health care provider may ask you to collect your urine ...

  18. Mercuric chloride poisoning

    MedlinePLUS

    Mercuric chloride is a very poisonous form of mercury. It is a type of mercury salt. There are different ... poisonings . This article discusses poisoning from swallowing mercuric chloride. This is for information only and not for ...

  19. Chloride in diet

    MedlinePLUS

    ... found in table salt or sea salt as sodium chloride. It is also found in many vegetables. Foods ... Nutrition Board. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. National Academy Press, Washington, DC, 2004.

  20. 4-(Carboxy­meth­yl)anilinium chloride

    PubMed Central

    Kechout, Habiba; Belhouas, Ratiba; Bouacida, Sofiane; Merazig, Hocine

    2009-01-01

    In the crystal of the title compound, C8H10NO2 +·Cl?, alternating layers of hydro­phobic and hydro­philic zones stack along the c axis. The chloride anions are sandwiched between the 4-(carboxy­meth­yl)anilinium layers, forming inter­molecular O—H?Cl and N—H?Cl hydrogen bonds with the ammonium and carboxyl groups of the cations. In addition, inter­molecular N—H?O and weak C—H?O and C—H?Cl hydrogen bonds help stabilize the crystal structure. PMID:21582845

  1. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  2. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  3. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  4. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  5. Ammonium nitrogen removal from wastewater with a three-dimensional electrochemical oxidation system.

    PubMed

    Ding, Jing; Zhao, Qing-Liang; Wei, Liang-Liang; Chen, Yang; Shu, Xin

    2013-01-01

    Ammonium-containing wastewater could cause the promotion of eutrophication and a hindrance to the disinfection of water supplies. In this study, the feasibility of removing low-concentration ammonium nitrogen from synthetic and real wastewater by electrochemical oxidation was investigated. Using laboratory-scale electrochemical systems, the effects of chloride concentration, current density, anode materials, cathode materials, electrode gap, initial ammonium concentration and three-dimensional particles on the removal of ammonium nitrogen and current efficiency (CE) were evaluated. Ammonium nitrogen removal was mainly dependent upon anode materials and current density. The performance of two- and three-dimensional electrochemical oxidation systems was comparatively discussed. Both particle electrodes could enhance ammonium nitrogen removal and increase CE. However, the mechanism of the process seemed to be different. Moreover, the interaction of zeolites adsorption and electrochemical oxidation on the anode in a three-dimensional system could favor the regeneration of zeolites. Surface morphology of the used Ru-Ir-Sn/Ti anode revealed its longer working life of electrocatalysis. The result of ammonium degradation for a real wastewater treatment plant effluent showed the degradation rates in a three-dimensional system increased by 1.4 times those in a two-dimensional system. PMID:23925182

  6. TOXICOLOGICAL REVIEW OF METHYL CHLORIDE [AND IRIS SUMMARY] (EXTERNAL PEER REVIEW DRAFT)

    EPA Science Inventory

    Methyl chloride (CAS No. 74-87-3) is a gaseous chlorohydrocarbon under ambient conditions. It is principally used in the manufacture of silicones, agrichemicals, methyl cellulose and quaternary amines. Numerous case reports involving overexposure over the last 60 years indicate t...

  7. B6) Quaternary Geology QUATERNARY GEOLOGY AND LANDFORMS BETWEEN

    E-print Network

    Briner, Jason P.

    The Quaternary geology and landforms in western New York State north of the southern Finger Lakes (Valley Heads recession across a scarp-dominated bedrock landscape from Batavia to the southern Lake Ontario shoreline. The complex sequence of proglacial lakes that accompanied glacial recession across the Great Lakes region

  8. Application of the rough sets theory in structure activity relationship of antielectrostatic ammonium compounds.

    PubMed

    Krysi?ski, Jerzy; Skrzypczak, Andrzej; Demski, Grzegorz

    2003-01-01

    The relationships between the chemical structure and the antielectrostatic effect of 112 ammonium compounds were analysed using the method of rough sets. The antielectrostatic activity was determined by measurements of the maximum voltage induced. Using the rough sets approach the smallest set of condition attributes significant for high quality of classification has been found. The resulting decision rules describe relations between the structure and the antielectrostatic properties of ammonium chlorides in terms of significant condition attributes. This may be helpful in predicting the structures of the new antielectrostatic compounds to be synthesized. PMID:13678321

  9. (4-Meth-oxy-phen-yl)methanaminium chloride.

    PubMed

    Kefi, Riadh; Matthias, Zeller; Ben Nasr, Cherif

    2011-01-01

    In the crystal structure of the title salt, C(8)H(12)NO(+)·Cl(-), the methoxy group of the cation is co-planar with the phenylene moiety with an r.m.s. deviation from the mean plane of only 0.005?Å. The ammonium N atom deviates from this plane by 1.403?(1)?Å. In the crystal, the (4-meth-oxy-phen-yl)methan-aminium cations and chloride anions are linked by N-H?Cl and C-H?O hydrogen bonds, resulting in an open framework architecture with hydrogen-bonded ammonium groups and chloride anions located in layers parallel to (011), separated by more hydrophobic layers with interdigitating anisole groups. PMID:21522388

  10. (4-Meth­oxy­phen­yl)methanaminium chloride

    PubMed Central

    Kefi, Riadh; Matthias, Zeller; Ben Nasr, Cherif

    2011-01-01

    In the crystal structure of the title salt, C8H12NO+·Cl?, the methoxy group of the cation is co-planar with the phenylene moiety with an r.m.s. deviation from the mean plane of only 0.005?Å. The ammonium N atom deviates from this plane by 1.403?(1)?Å. In the crystal, the (4-meth­oxy­phen­yl)methan­aminium cations and chloride anions are linked by N—H?Cl and C—H?O hydrogen bonds, resulting in an open framework architecture with hydrogen-bonded ammonium groups and chloride anions located in layers parallel to (011), separated by more hydrophobic layers with interdigitating anisole groups. PMID:21522388

  11. Quaternary polymethacrylate-magnesium aluminum silicate films: molecular interactions, mechanical properties and tackiness.

    PubMed

    Rongthong, Thitiphorn; Sungthongjeen, Srisagul; Siepmann, Juergen; Pongjanyakul, Thaned

    2013-12-15

    The aim of this study was to investigate the impact of the addition of magnesium aluminum silicate (MAS), a natural clay, on the properties of polymeric films based on quaternary polymethacrylates (QPMs). Two commercially available aqueous QPM dispersions were studied: Eudragit(®) RS 30D and Eudragit(®) RL 30D (the dry copolymers containing 5 and 10% quaternary ammonium groups, respectively). The composite QPM-MAS films were prepared by casting. Importantly, QPM interacted with MAS and formed small flocculates prior to film formation. Continuous films were obtained up to MAS contents of 19% (referred to the QPM dry mass). ATR-FTIR and PXRD revealed that the positively charged quaternary ammonium groups of QPM interacted with negatively charged SiO(-) groups of MAS, creating nanocomposite materials. This interaction led to improved thermal stability of the composite films. The puncture strength and elongation at break of dry systems decreased with increasing MAS content. In contrast, the puncture strength of the wet QPM-MAS films (upon exposure to acidic or neutral media) increased with increasing MAS content. Furthermore, incorporation of MAS into QPM films significantly decreased the latter's tackiness in the dry and wet state. These findings suggest that nanocomposite formation between QPM and MAS in the systems can enhance the strength of wet films and decrease their tackiness. Thus, MAS offers an interesting potential as novel anti-tacking agent for QPM coatings. PMID:24144950

  12. Cyclo­hexyl­ammonium nitrate

    PubMed Central

    Bagabas, Abdulaziz A.; Aboud, Mohamed F. A.; Shemsi, Ahsan M.; Addurihem, Emad S.; Al-Othman, Zeid A.; Chidan Kumar, C. S.; Fun, Hoong-Kun

    2014-01-01

    In the title salt, C6H14N+·NO3 ?, the cyclo­hexyl ring adopts a chair conformation. The ammonium group occupies an equatorial position and the crystal struture is stabilized by inter­molecular N—H?O hydrogen-bonding inter­actions, resulting in a three-dimensional network. PMID:24764971

  13. Robustness of Quaternary glacial cycles

    NASA Astrophysics Data System (ADS)

    Ganopolski, Andrei; Brovkin, Victor; Calov, Reinhard

    2015-04-01

    In spite of significant progress in paleoclimate reconstructions and modeling some aspects of Quaternary climate cycles are still poorly understood. Among them is the question of whether glacial cycles are deterministic and solely externally forced or, at least partially, they are stochastic. The answer to this question can only be obtained using a comprehensive Earth system models which incorporates all major components of the Earth system - atmosphere, ocean, land surface, northern hemisphere ice sheets, terrestrial biota and soil carbon, aeolian dust and marine biogeochemistry. Here, we used the Earth system model of intermediate complexity CLIMBER-2. The model was optimally tuned to reproduce climate, ice volume and CO2 variability for the last 0.8 million years. Using the same model version, we performed a large set of simulations covering the entire Quaternary (3 million years). By starting the model at different times (with the time step of 100,000 years) and using identical initial conditions we run the model for 500,000 years using the Earth's orbital variations as the only prescribed radiative forcing. We show that within less than 100,000 years after the beginning of each experiment the modeling results converge to the same solution which depends only on the orbital forcing and boundary conditions, such as topography and terrestrial sediment thickness for the ice sheets or volcanic CO2 outgassing for the carbon cycle. By using only several sets of the Northern Hemisphere orography and sediment thickness which represent different stages of landscape evolution during Quaternary, we are able to reproduce all major regimes of Quaternary long-term climate variability. Our results thus strongly support the notion that Quaternary glacial cycles are deterministic and externally forced.

  14. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents. (b) The ingredient meets the specifications...

  15. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents. (b) The ingredient meets the specifications...

  16. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food... GRAS § 184.1137 Ammonium carbonate. (a) Ammonium carbonate ((NH4)2CO3, CAS Reg. No. 8000-73-5) is...

  17. CHLORIDEDETERMINATION IN HIGH IONIC STRENGTH SOLUTION OF AMMONIUM ACETATE USING NEGATIVE ION ELECTRON SPRAY IONIZATION (HPLC/MS)

    EPA Science Inventory

    A precise ion chromatography method has been developed for the determination of chloride in high ionic strength ammonium acetate solutions (10-5 M-5 M) using sodium carbonate/sodium bicarbonate as eluent. Negative ion electrospray ionization (ESI) mass spectrometry was used for q...

  18. Antimicrobial and inhibitory enzyme activity of N-(benzyl) and quaternary N-(benzyl) chitosan derivatives on plant pathogens.

    PubMed

    Badawy, Mohamed E I; Rabea, Entsar I; Taktak, Nehad E M

    2014-10-13

    Chemical modification of a biopolymer chitosan by introducing quaternary ammonium moieties into the polymer backbone enhances its antimicrobial activity. In the present study, a series of quaternary N-(benzyl) chitosan derivatives were synthesized and characterized by (1)H-NMR, FT-IR and UV spectroscopic techniques. The antimicrobial activity against crop-threatening bacteria Agrobacterium tumefaciens and Erwinia carotovora and fungi Botrytis cinerea, Botryodiplodia theobromae, Fusarium oxysporum and Phytophthora infestans were evaluated. The results proved that the grafting of benzyl moiety or quaternization of the derivatives onto chitosan molecule was successful in inhibiting the microbial growth. Moreover, increase water-solubility of the compounds by quaternization significantly increased the activity against bacteria and fungi. Exocellular enzymes including polygalacturonase (PGase), pectin-lyase (PLase), polyphenol oxidase (PPOase) and cellulase were also affected at 1000 mg/L. These compounds especially quaternary-based chitosan derivatives that have good inhibitory effect should be potentially used as antimicrobial agents in crop protection. PMID:25037402

  19. Extraction of urea and ammonium ion

    NASA Technical Reports Server (NTRS)

    Anselmi, R. T.; Husted, R. R.; Schulz, J. R.

    1977-01-01

    Water purification system keeps urea and ammonium ion concentration below toxic limits in recirculated water of closed loop aquatic habitat. Urea is first converted to ammonium ions and carbon dioxide by enzygmatic action. Ammonium ions are removed by ion exchange. Bioburden is controlled by filtration through 0.45 micron millipore filters.

  20. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  1. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  2. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  3. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  4. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  5. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...NH4 )2 CO3 , CAS Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and...

  6. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...NH4 )2 CO3 , CAS Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and...

  7. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...NH4 )2 CO3 , CAS Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and...

  8. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...NH4 )2 CO3 , CAS Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and...

  9. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...NH4 )2 CO3 , CAS Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and...

  10. 76 FR 62311 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ...DHS-2008-0076] RIN 1601-AA52 Ammonium Nitrate Security Program AGENCY: National Protection...rulemaking (NPRM), entitled ``Ammonium Nitrate Security Program,'' which was published...regulate the sale and transfer of ammonium nitrate pursuant to section 563 of the...

  11. Phosphonium chloride for thermal storage

    NASA Technical Reports Server (NTRS)

    Sutton, J. G.; Heimlich, P. F.; Tepper, E. H.

    1972-01-01

    Development of systems for storage of thermal energy is discussed. Application of phosphonium chloride for heat storage through reversible dissociation is described. Chemical, physical, and thermodynamic properties of phosphonium chloride are analyzed and dangers in using phosphonium chloride are explained.

  12. Ammonium detection by formation of colored zebra-bands in a detecting tube.

    PubMed

    Hori, Tatsuaki; Niki, Keizou; Kiso, Yoshiaki; Oguchi, Tatsuo; Kamimoto, Yuki; Yamada, Toshiro; Nagai, Masahiro

    2010-06-15

    Ammonium ion was colorized by means of a diazo coupling reaction with 2-phenylphenol, where the color development reaction was conducted within 3min by using boric acid as a catalyst. The resulting colored solution (0.5ml) was supplied by suction to a detecting tube consisting of a nonwoven fabric test strip (2mm wide, 1mm thick, 150mm long) impregnated with benzylcetyldimethylammonium chloride in a stripe pattern and enclosed in a heat-shrinkable tube. When the colored solution was supplied to the detecting tube, blue zebra-bands formed, and the ammonium concentration was determined by counting the number of zebra-bands. The detection range was 1-20mg-Nl(-1). Ammonium ion in actual domestic wastewater samples was successfully detected by means of this method. PMID:20441924

  13. Andrei Sher and Quaternary science

    NASA Astrophysics Data System (ADS)

    Kuzmina, Svetlana; Lister, Adrian M.; Edwards, Mary E.

    2011-08-01

    Andrei Sher (1939-2008) was a key individual in Beringian studies who made substantial and original contributions, but also, importantly, built bridges between western and eastern Beringian scientists spanning some five decades of research. He is perhaps best known as a Quaternary palaeontologist, specializing in large mammals, and mammoths in particular, but his field of his scientific research was much broader, encompassing Quaternary geology, stratigraphy, geocryology, and paleoenvironmental reconstructions. He worked mainly in Siberia, in the Kolyma and Indigirka lowlands, and Chukotka, but also completed fieldwork in Alaska and Yukon through joint projects with American and Canadian scientists. Andrei was an active scientist until the last days of his life. He was involved in many different research projects ranging from mammoth evolution, fossil insects and environmental changes and ancient DNA. Without Andrei's connections between researchers, many unique discoveries would likely be unknown.

  14. Quaternary ecology: A paleoecological perspective

    SciTech Connect

    Delcourt, H.R.; Delcourt, P.A.

    1991-01-01

    This book considers issues and problems in ecology which may be illuminated, if not solved, by considering paleoecology. The five central chapters include a discussion of application of Quaternary ecology to future global climate change, including global warming. Other areas presented include: population dispersal, invasions, expansions, and migrations; plant successions; ecotones; factors in community structure; ecosystem patterns and processes. Published case studies are numerous. The role played by continuing climatic change in vegetation change is acknowledged but not stressed.

  15. Polyurethane-based polymer surface modifiers with alkyl ammonium copolyoxetane soft segments: Reaction engineering, surface morphology and antimicrobial behavior

    NASA Astrophysics Data System (ADS)

    Brunson, Kennard Marcellus, Jr.

    Concentrating quaternary (positive) charge at polymer surfaces is important for applications including layer-by-layer polyelectrolyte deposition and antimicrobial coatings. Prior techniques to introduce quaternary charge to the surface involve grafting of quaternary ammonium moieties to a substrate or using polyurethanes with modified hard segments however there are impracticalities involved with these techniques. In the case of the materials discussed, the quaternary charge is introduced via polyurethane based polymer surface modifiers (PSMs) with quaternized soft segments. The particular advantage to this method is that it utilizes the intrinsic phase separation between the hard and soft segments of polyurethanes. This phase separation results in the surface concentration of the soft segments. Another advantage is that unlike grafting, where modification has to take place after device fabrication, these PSMs can be incorporated with the matrix material during device fabrication. The soft segments of these quaternized polyurethanes are produced via ring opening co-polymerization of oxetane monomers which possess either a trifluoroethoxy (3FOx) side chains or a quaternary ammonium side chain (C12). These soft segments are subsequently reacted with 4,4'-(methylene bis (p-cyclohexyl isocyanate)), HMDI and butanediol (BD) to form the PSM. It was initially intended to increase the concentration of quaternary ammonium charge by increasing PSM soft segment molecular weight. Unexpectedly, produced blends with surface microscale phase separation. This observation prompted further investigation of the effect of PSM soft segment molecular weight on phase separation in PSM-base polyurethane blends and the subsequent effects of this phase separation on the biocidal activity. Analysis of the surface morphology via tapping mode atomic force microscopy (TM-AFM) and scanning electron microscopy (SEM) revealed varying complexities in surface morphology as a function of the PSM soft segment molecular weight and initial annealing temperature. Many of these features include what are described as nanodots (100-300 nm), micropits (0.5-2 mum) and micropeaks (1-10 mum). It was also observed that surface morphology continued to coarsen with time and that the larger features were typically observed in blends containing PSMs with low molecular weight soft segments. This appearance of surface morphological feature correlates with decreased biocidal activity of the PSM blends, that is, the PSM blends exhibit little to no activity upon development of phase separated features. A model has been developed for phase separation and concomitant reduction of surface quaternary charge. This model points the way to future work that will stabilize surface charge and provide durability of surface modification.

  16. Characterization of incubation experiments and development of an enrichment culture capable of ammonium oxidation under iron-reducing conditions

    NASA Astrophysics Data System (ADS)

    Huang, S.; Jaffé, P. R.

    2015-02-01

    Incubation experiments were conducted using soil samples from a forested riparian wetland where we have previously observed anaerobic ammonium oxidation coupled to iron reduction. Production of both nitrite and ferrous iron was measured repeatedly during incubations when the soil slurry was supplied with either ferrihydrite or goethite and ammonium chloride. Significant changes in the microbial community were observed after 180 days of incubation as well as in a continuous flow membrane reactor, using 16S rRNA gene PCR-denaturing gradient gel electrophoresis, 454 pyrosequencing, and real-time quantitative PCR analysis. We be Acidimicrobiaceae bacterium A6), belonging to the Acidimicrobiaceae family, whose closest cultivated relative is Ferrimicrobium acidiphilum (with 92% identity) and Acidimicrobium ferrooxidans (with 90% identity), might play a key role in this anaerobic biological process that uses ferric iron as an electron acceptor while oxidizing ammonium to nitrite. After ammonium was oxidized to nitrite, nitrogen loss proceeded via denitrification and/or anammox.

  17. Natrix -Scoring Sheet 1. 0.01 M Mg Chloride, 0.05 M MES pH 5.6, 2.0 M Lithium Sulfate

    E-print Network

    Hill, Chris

    Natrix - Scoring Sheet 1. 0.01 M Mg Chloride, 0.05 M MES pH 5.6, 2.0 M Lithium Sulfate 2. 0.01 M Mg.2 M K Chloride, 0.01 M Mg Sulfate, 0.05 M MES pH 5.6, 10% PEG 400 5. 0.2 M K Chloride, 0.01 M Mg Chloride, 0.05 M MES pH 5.6, 5% PEG 8000 6. 0.1 M Ammonium Sulfate, 0.01 M Mg Chloride, 0.05 M MES pH 5

  18. CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT OF CENTER WITH TOP OF SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  19. Formation of light absorbing organo-nitrogen species from evaporation of droplets containing glyoxal and ammonium sulfate

    NASA Astrophysics Data System (ADS)

    Lee, A.; Zhao, R.; Richard, L.; Liggio, G.; Li, S.; Abbatt, J.

    2013-12-01

    Formation of particle-phase organo-nitrogen compounds has been recently proposed via aqueous chemistry of glyoxal and ammonium sulfate in both dark and illuminated conditions. In the atmosphere, glyoxal can partition into aqueous droplets containing significant levels of different inorganic salts but their molecular interactions are still not well understood. Upon droplet evaporation, both the organics and inorganic ions become highly concentrated, accelerating reactions between them. To demonstrate this process, we investigated the formation of organo-nitrogen and light absorbing materials in evaporating droplets containing glyoxal and different ammonium salts including ammonium sulfate, ammonium nitrate and ammonium chloride. Our results demonstrate that evaporating glyoxal-ammonium sulfate droplets produce light absorbing species on a time scale of seconds, which is orders of magnitude faster than observed in bulk solutions. Using aerosol mass spectrometry, we show that particle-phase organics with high N:C ratios were formed when ammonium salts were used, and that the presence of sulfate ions promoted this chemistry. Since sulfate can also significantly enhance the Henry's law partitioning of glyoxal, our results highlight the atmospheric importance of such inorganic-organic interactions in aqueous phase aerosol chemistry.

  20. Comparison of the bacterial removal performance of silver nanoparticles and a polymer based quaternary amine functiaonalized silsesquioxane coated point-of-use ceramic water filters.

    PubMed

    Zhang, Hongyin; Oyanedel-Craver, Vinka

    2013-09-15

    This study compares the disinfection performance of ceramic water filters impregnated with two antibacterial compounds: silver nanoparticles and a polymer based quaternary amine functiaonalized silsesquioxane (poly(trihydroxysilyl) propyldimethyloctadecyl ammonium chloride (TPA)). This study evaluated these compounds using ceramic disks manufactures with clay obtained from a ceramic filter factory located in San Mateo Ixtatan, Guatemala. Instead of using full size ceramic water filters, manufactured 6.5 cm diameter ceramic water filter disks were used. Results showed that TPA can achieve a log bacterial reduction value of 10 while silver nanoparticles reached up to 2 log reduction using a initial concentration of bacteria of 10(10)-10(11)CFU/ml. Similarly, bacterial transport demonstrated that ceramic filter disks painted with TPA achieved a bacterial log reduction value of 6.24, which is about 2 log higher than the values obtained for disks painted with silver nanoparticles (bacterial log reduction value: 4.42). The release of both disinfectants from the ceramic materials to the treated water was determined measuring the effluent concentrations in each test performed. Regarding TPA, about 3% of the total mass applied to the ceramic disks was released in the effluent over 300 min, which is slightly lower than the release percentage for silver nanoparticles (4%). This study showed that TPA provides a comparable disinfection performance than silver nanoparticles in ceramic water filter. Another advantage of using TPA is the cost as the price of TPA is considerable lower than silver nanoparticles. In spite of the use of TPA in several medical related products, there is only partial information regarding the health risk associated with the ingestion of this compound. Additional long-term toxicological information for TPA should be evaluated before its future application in ceramic water filters. PMID:23770490

  1. The Influence of the Anionic Counter-Ion on the Activity of Ammonium Substituted Hoveyda-Type Olefin Metathesis Catalysts in Aqueous Media

    NASA Astrophysics Data System (ADS)

    Gu?ajski, ?ukasz; Grela, Karol

    Polar olefin metathesis catalysts, bearing an ammonium group are presented. The electron withdrawing ammonium group not only activates the catalysts electronically, but at the same time makes the catalysts more hydrophilic. Catalysts can be therefore efficiently used not only in traditional media, such as methylene chloride and toluene, but also in technical-grade alcohols, alcohol— water mixtures and in neat water. Finally, in this overview the influence of the anionic counter-ion on the activity of ammonium substituted Hoveyda-type olefin metathesis catalysts in aqueous media is presented.

  2. Late Quaternary history of the Atacama Desert

    E-print Network

    #12;#12;#12;#12;#12;73 Late Quaternary history of the Atacama Desert Claudio Latorre, Julio L and Kate Rylander Of the major subtropical deserts found in the Southern Hemisphere, the Atacama Desert is the driest. Throughout the Quaternary, the most pervasive climatic influence on the desert has been

  3. Ancient biomolecules in Quaternary palaeoecology

    NASA Astrophysics Data System (ADS)

    Hofreiter, Michael; Collins, Matthew; Stewart, John R.

    2012-02-01

    The last few years have seen an enormous proliferation of ancient biomolecules research, especially in the field of ancient DNA. Ancient DNA studies have been transformed by the advent of next generation sequencing, with the first Pleistocene sample being analysed in 2005, and several complete and draft genomes that have been compiled from ancient DNA to date. At the same time, although less conspicuous, research on ancient proteins has also seen advances, with the time limit for research on ancient biomolecules now extending to over 1 million years. Here we review which effects these developments have on research in Quaternary science. We identify several lines of research that have the potential to profit substantially from these recent developments in ancient biomolecules research. First, the identification of taxa can be made using ancient biomolecules, and in the case of ancient DNA, specimens can even be assigned to specific populations within a species. Second, increasingly large DNA data sets from Pleistocene animals allow the elucidation of ever more precise pictures of the population dynamic processes whereby organisms respond to climate and environmental change. With the accompanying better understanding of process in the Quaternary, past ecologies can also more realistically be interpreted from proxy data sets. The dominant message from this research so far is that the Quaternary saw a great deal more dynamism in populations than had been forecast by conventional palaeoecology. This suggests that reconstructions of past environmental conditions need to be done with caution. Third, ancient DNA can also now be obtained directly from sediments to elucidate the presence of both plant and animal species in an area even in the absence of identifiable fossils, be it macro- or micro-fossils. Finally, the analysis of proteins enables the identification of bone remains to genus and sometimes species level far beyond the survival time of DNA, at least in temperate regions, illustrating that precise data is now forthcoming from seemingly unlikely sources. Together, these approaches allow the study of environmental dynamics throughout a substantial part, and perhaps even the entire Quaternary (the last 2.6 million years).

  4. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Explosives, blasting, type E, and Explosives, blasting, type B, Division 1.5...Ammonium nitrate fertilizer, Division 5.1...and ammonium nitrate fertilizers classed as Division...Explosives, blasting, type B, and...

  5. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Explosives, blasting, type E, and Explosives, blasting, type B, Division 1.5...Ammonium nitrate fertilizer, Division 5.1...and ammonium nitrate fertilizers classed as Division...Explosives, blasting, type B, and...

  6. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Explosives, blasting, type E, and Explosives, blasting, type B, Division 1.5...Ammonium nitrate fertilizer, Division 5.1...and ammonium nitrate fertilizers classed as Division...Explosives, blasting, type B, and...

  7. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Explosives, blasting, type E, and Explosives, blasting, type B, Division 1.5...Ammonium nitrate fertilizer, Division 5.1...and ammonium nitrate fertilizers classed as Division...Explosives, blasting, type B, and...

  8. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Explosives, blasting, type E, and Explosives, blasting, type B, Division 1.5...Ammonium nitrate fertilizer, Division 5.1...and ammonium nitrate fertilizers classed as Division...Explosives, blasting, type B, and...

  9. Comparative toxicity of ammonium and nitrate compounds to Pacific treefrog and African clawed frog tadpoles

    SciTech Connect

    Schuytema, G.S.; Nebeker, A.V.

    1999-10-01

    The effects of ammonium nitrate, ammonium chloride, ammonium sulfate, and sodium nitrate on survival and growth of Pacific treefrog (Pseudacris regilla [Baird and Girard]) and African clawed frog (Xenopus laevis [Daudin]) tadpoles were determined in static-renewal tests. The 10-d ammonium nitrate and ammonium sulfate LC50s for P. regilla were 55.2 and 89.7 mg/L NH{sub 4}-N, respectively. The 10-d LC50s for X. laevis for the three ammonium compounds ranged from 45 to 64 mg/L NH{sub 4}-N. The 10-d sodium nitrate LC50s were 266.2 mg/L NO{sub 3}-N for P. regilla and 1,236.2 mg/L NO{sub 3}-N for X. laevis. The lowest observed adverse effect level (LOAEL) of ammonium compound based on reduced length or weight was 24.6 mg/L NH{sub 4}-N for P. regilla and 99.5 mg/L NH{sub 4}-N for X. laevis. The lowest sodium nitrate LOAELs based on reduced length or weight were {lt}30.1 mg/L NO{sub 3}-N for P. regilla and 126.3 mg/L NO{sub 3}-N for X. laevis. Calculated un-ionized NH{sub 3} comprised 0.3 to 1.0% of measured NH{sub 4}-N concentrations. Potential harm to amphibians could occur if sensitive life stages were impacted by NH{sub 4}-N and NO{sub 3}-N in agricultural runoff or drainage for a sufficiently long period.

  10. Ammonium assmilation in spruce ectomycorrhizas

    SciTech Connect

    Chalot, M.; Brun, A.; Botton, B. ); Stewart, G. )

    1990-05-01

    Assimilation of labelled NH{sub 4}{sup +} into amino acids has been followed in ectomycorrhizal roots of spruce. Over an 18 h period of NH{sub 4}{sup +} feeding, Gln, Glu and Ala became the most abundant amino acids. Gln was also the most highly labelled amino acid during the experiment, followed by Glu and Ala. This result indicates that Gln synthesis is an important ammonium utilization reaction in spruce mycorrhizas. Addition of MSX to NH{sub 4}{sup +} fed mycorrhizas caused an inhibition of Gln accumulation with a corresponding increase in Glu, Ala and Asn levels. The supply of MSX induced a sharp diminution of {sup 15}N enrichment in both amino and amido groups of glutamine. In contrast, the {sup 15}N incorporation into Glu and derivatives (Ala and Asp) remained very high. This study demonstrates that the fungal glutamate dehydrogenase is quite operative in spruce ectomycorrhizas since it is able to sustain ammonium assimilation when glutamine synthetase is inhibited.

  11. Structural study of ammonium metatungstate

    SciTech Connect

    Christian, Joel B. Whittingham, M. Stanley

    2008-08-15

    Several techniques have been used to study the structure of the Keggin-type polyoxometalate salt ammonium metatungstate (AMT)-(NH{sub 4}){sub 6}[H{sub 2}W{sub 12}O{sub 40}]*nH{sub 2}O, a potential fuel cell catalyst. The dehydrated salt is comprised of a mixture of crystallites of different unit cells in a centered eutactic cubic configuration, with an average unit cell of a{approx_equal}12.295. Varied orientations of the Keggin ions in the cubic arrangement create the differences, and orientational variation within each unit cell size represents an energy well. Progressive hydration of each crystallite leads to expansion of the lattice, with the degree of expansion depending on the locations of the water added in relation to the Keggin ion, which is influenced by cation location and hydrogen bonding. The structural hypothesis is supported by electron diffraction of single and multicrystal samples, by powder density measurements, X-ray powder diffraction studies, synchrotron powder X-ray diffraction, and a priori structural modeling studies. Based on the structure, projected active site densities are compared with nanostructured platinum catalysts for fuel cell application. - Graphical abstract: The structure of ammonium metatungstate powders are highly dependent on hydration and POM molecule rotation, with cation and hydrogen bonding forces directing a mixture of structures that have been studied with bulk and single-crystal methods. The illustration shows Monte Carlo simulated anion structural disorder for the fully dehydrated form of the title compound.

  12. Delimiting the binding site for quaternary ammonium lidocaine derivatives in the acetylcholine receptor channel.

    PubMed

    Pascual, J M; Karlin, A

    1998-11-01

    The triethylammonium QX-314 and the trimethylammonium QX-222 are lidocaine derivatives that act as open-channel blockers of the acetylcholine (ACh) receptor. When bound, these blockers should occlude some of the residues lining the channel. Eight residues in the second membrane-spanning segment (M2) of the mouse-muscle alpha subunit were mutated one at a time to cysteine and expressed together with wild-type beta, gamma, and delta subunits in Xenopus oocytes. The rate constant for the reaction of each substituted cysteine with 2-aminoethyl methanethiosulfonate (MTSEA) was determined from the time course of the irreversible effect of MTSEA on the ACh-induced current. The reactions were carried out in the presence and absence of ACh and in the presence and absence of QX-314 and QX-222. These blockers had no effect on the reactions in the absence of ACh. In the presence of ACh, both blockers retarded the reaction of extracellularly applied MTSEA with cysteine substituted for residues from alphaVal255, one third of the distance in from the extracellular end of M2, to alphaGlu241, flanking the intracellular end of M2, but not with cysteine substituted for alphaLeu258 or alphaGlu262, at the extracellular end of M2. The reactions of MTSEA with cysteines substituted for alphaLeu258 and alphaGlu262 were considerably faster in the presence of ACh than in its absence. That QX-314 and QX-222 did not protect alphaL258C and alphaE262C against reaction with MTSEA in the presence of ACh implies that protection of the other residues was due to occlusion of the channel and not to the promotion of a less reactive state from a remote site. Given the 12-A overall length of the blockers and the alpha-helical conformation of M2 in the open state, the binding site for both blockers extends from alphaVal255 down to alphaSer248. PMID:9806969

  13. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and...

  14. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and...

  15. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and...

  16. Supramolecular assembly of borate with quaternary ammonium: Crystal structure and tunable luminescent properties

    NASA Astrophysics Data System (ADS)

    Liang, Jie; Wang, Yong-gang; Wang, Ying-xia; Liao, Fu-hui; Lin, Jian-hua

    2013-04-01

    A new borate [C6H16N][B5O6(OH)4] (1) is synthesized hydrothermally by the reaction of isopropyltrimethylammonium hydroxide with boric acid. It crystallizes in the triclinic space group P-1 with the parameters a=9.1578(10) Å, b=9.372(9) Å, c=9.9812(10) Å, ?=66.508(2)°, ?=74.751(2)°, ?=81.893(2)°. The [B5O6(OH)4]- anions are interlinked via hydrogen bonding forming a 3D supramolecular network containing large cavities, where reside the (CH3)3(i-C3H7) N+ cations. This borate shows tunable luminescent properties with temperature, heating-treatment, exciting-light, and solvents. The fluorescent intensity of 1 enhances 6-fold with decreasing the temperature from 25 K to 78 K. By treatment under different temperatures, the luminescence of 1 shifted from blue to white and the sample treated at 230 °C emits bright white light to naked eyes. The hybrid borate can disperse in different solvents, and shows a red-shifted and intense emission in polar solvents.

  17. Intriguing Role of a Quaternary Ammonium Cation in the Dissociation Chemistry of Keggin Polyoxometalate Anions

    NASA Astrophysics Data System (ADS)

    Cao, Jie; Li, Chenchen; Zhang, Zhengxiang; Xu, Chong; Yan, Jie; Cui, Fengyun; Hu, Changwen

    2012-02-01

    The gas-phase fragmentations of a series of Keggin polyoxometalate anions with molecular formula of TBAn[XM12O40] (X = P, Si; M = Mo, W) were studied by electrospray ionization tandem mass spectrometry. The bare polyoxoanions [XM12O40]n- as well as the non-covalent complexes {TBA[XM12O40]}(n-1)- and {TBAm[XM12O40]2}3- displayed characteristic dissociation pathways. Fragmentation of [XM12O40]n- led to pairs of complementary product anions whose total stoichiometry and charge matched those of the precursor anion, consistent with the previous study by Ma et al. The nature of the non-covalent interaction between [XM12O40]n- and TBA+ was addressed in detail via the example of {TBA[XM12O40]}(n-1)-. The non-covalent interaction [1] primarily dominated by the Coulombic attraction of the opposite charges completely changed the dissociation chemistry of [XM12O40]n-. The non-covalent complexes {TBA[XM12O40]}(n-1)- and {TBAm[XM12O40]2}3-, formed by the charge reduction during the electrospray process, underwent distinct dissociation routes: {TBA[XM12O40]}(n-1)- fragmented to give rise to its product ion {(C4H9)[XM12O40]}(n-1)- by cleaving the N-C covalent bond inside the TBA+ cation whereas {TBAm[XM12O40]2}3- dissociated into a pair of product ions, {TBAi[XM12O40]}2- and {TBAm-i[XM12O40]}-, by breaking the non-covalent bond between [XM12O40]n- and TBA+. In addition, energy-variable CID was used to map the relative stabilities of the ion clusters in the gas phase, which was in excellent agreement with the relative orders of thermal stability in the condensed phase.

  18. A novel application of quaternary ammonium compounds as antibacterial hybrid coating on glass surfaces.

    PubMed

    Saif, Muhammad Jawwad; Anwar, Jamil; Munawar, Munawar Ali

    2009-01-01

    A hybrid coating is prepared on a glass surface by a sol-gel process using tetraethoxysilane (TEOS) and Q(4)N(+)-Si(OR)(3). Transparent coatings with smooth surfaces were investigated against both Gram-positive (Escherichia coli) and Gram-negative bacteria (Staphylococcus aureus). A rapid decrease of the count for both strains was observed within 72 h. A significant correlation has been observed between the concentration of Q(4)N(+)-Si(OR)(S) and the antibacterial activity which has been thoroughly investigated. PMID:19115872

  19. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and...

  20. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and...

  1. Effect of ammonium sulfate, ammonium chloride and root-zone acidity on inorganic ion content of tobacco

    NASA Technical Reports Server (NTRS)

    Vessey, J. K.; Raper, C. D. Jr; Henry, L. T.; Raper CD, J. r. (Principal Investigator)

    1990-01-01

    Tobacco plants (Nicotiana tabacum L. cv NC82) were supplied with (NH4)2SO4 or NH4Cl at root-zone pH of 6.0 and 4.5 in hydroponic culture for 28 days. Dry matter accumulation, total N and C content, and leaf area and number were not affected by the NH4+ source or root-zone pH. Plants supplied with NH4Cl accumulated up to 1.2 mM Cl g DW-1, but accumulated 37% less inorganic H2PO4- and 47% less SO4(2-) than plants supplied with (NH4)2SO4. The large Cl- accumulation resulted in NH4Cl- supplied plants having a 31% higher inorganic anion (NO3-, H2, PO4-, SO4(2-), and Cl-) charge. This higher inorganic anion charge in the NH4Cl-supplied plants was balanced by a similar increase in K+ charge. Plants supplied with NH4Cl accumulated greater concentrations of Cl- in leaves (up to 5.1% of DW) than plants supplied with (NH4)2SO4 (less than -% DW). Despite the high Cl- concentration of leaves in NH4Cl supplied plants, these plants showed no symptoms of Cl- toxicity. This demonstrates that toxicity symptoms are not due solely to an interaction between high Cl- concentration in tissue and NH4+ nutrition. The increase in root-zone acidity to pH 4.5 from 6.0 did not induce toxicity symptoms.

  2. THE SALTING OUT OF GELATIN INTO TWO LIQUID LAYERS WITH SODIUM CHLORIDE AND OTHER SALTS

    PubMed Central

    McBain, James W.; Kellogg, Frederick

    1928-01-01

    1. Conditions under which gelatin may be salted out into two liquid layers at 35° were studied. 2. The equilibria governing the amounts and composition of the layers salted out with sodium chloride are found to accord with the requirements of the phase rule for the quaternary system gelatin-sodium chloride-hydrogen ion-water. 3. So far, soaps and gelatin are found to be surprisingly similar in their behaviour and definite indications are given as to where further similarities may be sought. 4. It is evident from this work that the term "coagulation" as ordinarily applied to the salting out of proteins is definitely a misnomer. PMID:19872438

  3. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  4. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  5. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  6. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  7. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  8. 76 FR 46907 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-03

    ...This proposed rule would implement anti-terrorism measures to better secure the homeland. The Department of Homeland Security would regulate the sale and transfer of ammonium nitrate pursuant to section 563 of the Fiscal Year 2008 Department of Homeland Security Appropriations Act with the purpose of preventing the use of ammonium nitrate in an act of terrorism. This proposed rule seeks......

  9. Ammonium content and buoyancy in midwater cephalopods

    E-print Network

    Thuesen, Erik V.

    Ammonium content and buoyancy in midwater cephalopods Brad A. Seibela,*, Shana K. Goffredib , Erik the cation concentrations in several midwater cephalopod species. High NH4 + levels were confirmed in cephalopods is the exchange of sodium for ammonium ions creating low-density fluids that impart lift (Clarke

  10. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...alginate (CAS Reg. No. 9005-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents....

  11. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...alginate (CAS Reg. No. 9005-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents....

  12. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...alginate (CAS Reg. No. 9005-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Ammonium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents....

  13. 76 FR 62311 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ... FR 64280 (advance notice of proposed rulemaking); 76 FR 46908 (notice of proposed rulemaking... Program Web site in mid-October at http://www.dhs.gov/ files/ ] programs/ammonium-nitrate-security-program...; ] DEPARTMENT OF HOMELAND SECURITY Office of the Secretary 6 CFR Part 31 RIN 1601-AA52 Ammonium Nitrate...

  14. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.170 Ammonium formate. The food additive, partially ammonium formate, may be safely used in...) To assure safe use of the additive, in addition to the other information required by the Federal...

  15. Ammonium nonanoate broadcast application over onions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonium nonanoate occurs in nature and is primarily formed from biodegradation of higher fatty acids. Racer (40% ammonium nonaoate) is a potential contact herbicide for weed control in organic crop production. Field research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determin...

  16. 21 CFR 556.375 - Maduramicin ammonium.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...of maduramicin ammonium in chickens as follows: (a) A tolerance...ammonium (marker residue) in chickens is 0.38 parts per million...residues in uncooked edible chicken tissues are: 0.24 parts per million in muscle; 0.72 parts per...

  17. 21 CFR 556.375 - Maduramicin ammonium.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...of maduramicin ammonium in chickens as follows: (a) A tolerance...ammonium (marker residue) in chickens is 0.38 parts per million...residues in uncooked edible chicken tissues are: 0.24 parts per million in muscle; 0.72 parts per...

  18. 21 CFR 556.375 - Maduramicin ammonium.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...of maduramicin ammonium in chickens as follows: (a) A tolerance...ammonium (marker residue) in chickens is 0.38 parts per million...residues in uncooked edible chicken tissues are: 0.24 parts per million in muscle; 0.72 parts per...

  19. 21 CFR 556.375 - Maduramicin ammonium.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...of maduramicin ammonium in chickens as follows: (a) A tolerance...ammonium (marker residue) in chickens is 0.38 parts per million...residues in uncooked edible chicken tissues are: 0.24 parts per million in muscle; 0.72 parts per...

  20. 21 CFR 556.375 - Maduramicin ammonium.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...of maduramicin ammonium in chickens as follows: (a) A tolerance...ammonium (marker residue) in chickens is 0.38 parts per million...residues in uncooked edible chicken tissues are: 0.24 parts per million in muscle; 0.72 parts per...

  1. Chloride removal from vitrification offgas

    SciTech Connect

    Slaathaug, E.J.

    1995-06-01

    This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations.

  2. 78 FR 32690 - Certain Ammonium Nitrate From Ukraine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ...731-TA-894 (Review)] Certain Ammonium Nitrate From Ukraine Determination On the basis...antidumping duty order on certain ammonium nitrate from Ukraine would be likely to lead to...May 2013), entitled Certain Ammonium Nitrate from Ukraine: Investigation No....

  3. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Ammonium phosphate, monobasic. 184.1141a Section 184...Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4 H2 PO4 , CAS...

  4. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Ammonium phosphate, monobasic. 184.1141a Section 184...Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4 H2 PO4 , CAS...

  5. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Zinc ammonium phosphate (generic). 721.10302 Section...Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance...identified generically as zinc ammonium phosphate (PMN P-00-442) is subject...

  6. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Zinc ammonium phosphate (generic). 721.10302 Section...Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance...identified generically as zinc ammonium phosphate (PMN P-00-442) is subject...

  7. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Ammonium phosphate, monobasic. 184.1141a Section 184...Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4 H2 PO4 , CAS...

  8. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Ammonium phosphate, monobasic. 184.1141a Section 184...Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4 H2 PO4 , CAS...

  9. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Zinc ammonium phosphate (generic). 721.10302 Section...Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance...identified generically as zinc ammonium phosphate (PMN P-00-442) is subject...

  10. Quaternary polymethacrylate-magnesium aluminum silicate films: Water uptake kinetics and film permeability.

    PubMed

    Rongthong, Thitiphorn; Sungthongjeen, Srisagul; Siepmann, Florence; Siepmann, Juergen; Pongjanyakul, Thaned

    2015-07-25

    The aim of this study was to investigate the impact of the addition of different amounts of magnesium aluminum silicate (MAS) to polymeric films based on quaternary polymethacrylates (QPMs, here Eudragit RS and RL). MAS contains negatively charged SiO(-) groups, while QPM contains positively charged quaternary ammonium groups. The basic idea is to be able to provide desired water and drug permeability by simply varying the amount of added MAS. Thin, free films of varying composition were prepared by casting and exposed to 0.1M HCl and pH 6.8 phosphate buffer. The water uptake kinetics and water vapor permeability of the systems were determined gravimetrically. The transport of propranolol HCl, acetaminophen, methyl-, ethyl- and propylparaben across thin films was studied using side-by-side diffusion cells. A numerical solution of Fick's second law of diffusion was applied to determine the apparent compound diffusion coefficients, partition coefficients between the bulk fluids and the films as well as the apparent film permeability for these compounds. The addition of MAS resulted in denser inner film structures, at least partially due to ionic interactions between the positively charged quaternary ammonium groups and the negatively charged SiO(-) groups. This resulted in lower water uptake, reduced water vapor permeability and decreasing apparent compound diffusivities. In contrast, the affinity of the investigated drugs and parabens to the films substantially increased upon MAS addition. The obtained new knowledge can be helpful for the development of novel coating materials (based on QPM-MAS blends) for controlled-release dosage forms. PMID:26004005

  11. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...nitrate or ammonium nitrate fertilizer not listed in § 176.410... (2) Ammonium nitrate fertilizer, Division 5.1 (oxidizer... (4) Ammonium nitrate fertilizer, Class 9, UN 2071. ...is Explosives, blasting, type E, Division 1.5...

  12. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...nitrate or ammonium nitrate fertilizer not listed in § 176.410... (2) Ammonium nitrate fertilizer, Division 5.1 (oxidizer... (4) Ammonium nitrate fertilizer, Class 9, UN 2071. ...is Explosives, blasting, type E, Division 1.5...

  13. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...nitrate or ammonium nitrate fertilizer not listed in § 176.410... (2) Ammonium nitrate fertilizer, Division 5.1 (oxidizer... (4) Ammonium nitrate fertilizer, Class 9, UN 2071. ...is Explosives, blasting, type E, Division 1.5...

  14. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...nitrate or ammonium nitrate fertilizer not listed in § 176.410... (2) Ammonium nitrate fertilizer, Division 5.1 (oxidizer... (4) Ammonium nitrate fertilizer, Class 9, UN 2071. ...is Explosives, blasting, type E, Division 1.5...

  15. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...nitrate or ammonium nitrate fertilizer not listed in § 176.410... (2) Ammonium nitrate fertilizer, Division 5.1 (oxidizer... (4) Ammonium nitrate fertilizer, Class 9, UN 2071. ...is Explosives, blasting, type E, Division 1.5...

  16. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...glufosinate ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...hydroxymethylphosphinyl)propanoic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

  17. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...glufosinate-ammonium (butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...3-methylphosphinico-propionic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

  18. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...glufosinate ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...hydroxymethylphosphinyl)propanoic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

  19. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  20. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  1. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  2. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  3. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  4. PHOTOOXIDATION OF ALLYL CHLORIDE

    EPA Science Inventory

    The photooxidation of allyl chloride was studied by irradiation either in 100-L Teflon bags or in a 22.7-cu m Teflon smog chamber in the presence of added NOx. In the absence of added hydrocarbons, the reaction involves a Cl atom chain, which leads to a highly reactive system. A ...

  5. SOURCE ASSESSMENT: POLYVINYL CHLORIDE

    EPA Science Inventory

    This report summarizes data on air emissions from the polyvinyl chloride (PVC) industry. PVC is manufactured by 20 companies at 35 plants. Each plant uses one or more of four possible polymerization processes: (1) suspension polymerization, (2) emulsion polymerization, (3) bulk p...

  6. The comparison of cation-anion interactions of phosphonium- and ammonium-based ionic liquids - A theoretical investigation

    NASA Astrophysics Data System (ADS)

    Lü, Renqing; Lin, Jin; Lu, Yukun; Liu, Dong

    2014-03-01

    The phosphonium- and ammonium-based ionic liquids combined with three anions, such as chloride, tetrafluoroborate and trifluoromethanesulfonate were used to perform a systematic study by theoretical method. The results demonstrate that the cation-anion interaction energies between phosphonium-based ionic liquids are slightly larger than that of their analogues. The larger phosphonium cations can form associated species that chloride, tetrafluoroborate, and trifluoromethanesulfonate anions are able to approach the centre of positive charge more closely than it can in the equivalent nitrogen-based cation due to the less steric effect of phosphorium cation.

  7. 3,4-Dimethyl­anilinium chloride monohydrate

    PubMed Central

    Bouacida, Sofiane; Belhouas, Ratiba; Kechout, Habiba; Merazig, Hocine; Bénard-Rocherullé, Patricia

    2009-01-01

    The crystal structure of the title compound, C8H12N+·Cl?·H2O, consists of hydro­phobic layers of dimethyl­anilinium cations parallel to the bc plane alternated by hydro­philic layers of chloride anions and water mol­ecules. The layers are linked by N—H?O and N—H?Cl hydrogen bonds involving the ammonium groups of the cations. The cohesion of the ionic structure is further stabilized by O—H?Cl hydrogen-bonding inter­actions. PMID:21582279

  8. Identification and Functional Analysis of an Ammonium Transporter in Streptococcus mutans

    PubMed Central

    Ardin, Arifah Chieko; Fujita, Kazuyo; Nagayama, Kayoko; Takashima, Yukiko; Nomura, Ryota; Nakano, Kazuhiko; Ooshima, Takashi; Matsumoto-Nakano, Michiyo

    2014-01-01

    Streptococcus mutans, a Gram-positive bacterium, is considered to be a major etiologic agent of human dental caries and reported to form biofilms known as dental plaque on tooth surfaces. This organism is also known to possess a large number of transport proteins in the cell membrane for export and import of molecules. Nitrogen is an essential nutrient for Gram-positive bacteria, though alternative sources such as ammonium can also be utilized. In order to obtain nitrogen for macromolecular synthesis, nitrogen-containing compounds must be transported into the cell. However, the ammonium transporter in S. mutans remains to be characterized. The present study focused on characterizing the ammonium transporter gene of S. mutans and its operon, while related regulatory genes were also analyzed. The SMU.1658 gene corresponding to nrgA in S. mutans is homologous to the ammonium transporter gene in Bacillus subtilis and SMU.1657, located upstream of the nrgA gene and predicted to be glnB, is a member of the PII protein family. Using a nrgA-deficient mutant strain (NRGD), we examined bacterial growth in the presence of ammonium, calcium chloride, and manganese sulfate. Fluorescent efflux assays were also performed to reveal export molecules associated with the ammonium transporter. The growth rate of NRGD was lower, while its fluorescent intensity was much higher as compared to the parental strain. In addition, confocal laser scanning microscopy revealed that the structure of biofilms formed by NRGD was drastically different than that of the parental strain. Furthermore, transcriptional analysis showed that the nrgA gene was co-transcribed with the glnB gene. These results suggest that the nrgA gene in S. mutans is essential for export of molecules and biofilm formation. PMID:25229891

  9. Identification and functional analysis of an ammonium transporter in Streptococcus mutans.

    PubMed

    Ardin, Arifah Chieko; Fujita, Kazuyo; Nagayama, Kayoko; Takashima, Yukiko; Nomura, Ryota; Nakano, Kazuhiko; Ooshima, Takashi; Matsumoto-Nakano, Michiyo

    2014-01-01

    Streptococcus mutans, a Gram-positive bacterium, is considered to be a major etiologic agent of human dental caries and reported to form biofilms known as dental plaque on tooth surfaces. This organism is also known to possess a large number of transport proteins in the cell membrane for export and import of molecules. Nitrogen is an essential nutrient for Gram-positive bacteria, though alternative sources such as ammonium can also be utilized. In order to obtain nitrogen for macromolecular synthesis, nitrogen-containing compounds must be transported into the cell. However, the ammonium transporter in S. mutans remains to be characterized. The present study focused on characterizing the ammonium transporter gene of S. mutans and its operon, while related regulatory genes were also analyzed. The SMU.1658 gene corresponding to nrgA in S. mutans is homologous to the ammonium transporter gene in Bacillus subtilis and SMU.1657, located upstream of the nrgA gene and predicted to be glnB, is a member of the PII protein family. Using a nrgA-deficient mutant strain (NRGD), we examined bacterial growth in the presence of ammonium, calcium chloride, and manganese sulfate. Fluorescent efflux assays were also performed to reveal export molecules associated with the ammonium transporter. The growth rate of NRGD was lower, while its fluorescent intensity was much higher as compared to the parental strain. In addition, confocal laser scanning microscopy revealed that the structure of biofilms formed by NRGD was drastically different than that of the parental strain. Furthermore, transcriptional analysis showed that the nrgA gene was co-transcribed with the glnB gene. These results suggest that the nrgA gene in S. mutans is essential for export of molecules and biofilm formation. PMID:25229891

  10. Sodium Chloride (Catheter Flush) Injection

    MedlinePLUS

    ... use a sodium chloride flush several times a day. Your health care provider will determine the number of sodium chloride flushes you will need a day. ... health care provider probably will give you several days supply of sodium chloride. You will be told ...

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

    PubMed

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

    2015-02-01

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

  12. Tn6188 - A Novel Transposon in Listeria monocytogenes Responsible for Tolerance to Benzalkonium Chloride

    PubMed Central

    Muhterem-Uyar, Meryem; Zaiser, Andreas; Stessl, Beatrix; Guinane, Caitriona M.; Cotter, Paul D.; Wagner, Martin; Schmitz-Esser, Stephan

    2013-01-01

    Controlling the food-borne pathogen Listeria (L.) monocytogenes is of great importance from a food safety perspective, and thus for human health. The consequences of failures in this regard have been exemplified by recent large listeriosis outbreaks in the USA and Europe. It is thus particularly notable that tolerance to quaternary ammonium compounds such as benzalkonium chloride (BC) has been observed in many L. monocytogenes strains. However, the molecular determinants and mechanisms of BC tolerance of L. monocytogenes are still largely unknown. Here we describe Tn6188, a novel transposon in L. monocytogenes conferring tolerance to BC. Tn6188 is related to Tn554 from Staphylococcus (S.) aureus and other Tn554-like transposons such as Tn558, Tn559 and Tn5406 found in various Firmicutes. Tn6188 comprises 5117 bp, is integrated chromosomally within the radC gene and consists of three transposase genes (tnpABC) as well as genes encoding a putative transcriptional regulator and QacH, a small multidrug resistance protein family (SMR) transporter putatively associated with export of BC that shows high amino acid identity to Smr/QacC from S. aureus and to EmrE from Escherichia coli. We screened 91 L. monocytogenes strains for the presence of Tn6188 by PCR and found Tn6188 in 10 of the analyzed strains. These isolates were from food and food processing environments and predominantly from serovar 1/2a. L. monocytogenes strains harboring Tn6188 had significantly higher BC minimum inhibitory concentrations (MICs) (28.5 ± 4.7 mg/l) than strains without Tn6188 (14 ± 3.2 mg/l). Using quantitative reverse transcriptase PCR we could show a significant increase in qacH expression in the presence of BC. QacH deletion mutants were generated in two L. monocytogenes strains and growth analysis revealed that ?qacH strains had lower BC MICs than wildtype strains. In conclusion, our results provide evidence that Tn6188 is responsible for BC tolerance in various L. monocytogenes strains. PMID:24098567

  13. New urethane oligodimethacrylates with quaternary alkylammonium for formulating dental composites.

    PubMed

    Buruiana, Tinca; Melinte, Violeta; Popa, Ionela D; Buruiana, Emil C

    2014-04-01

    The aim of this study was to prepare urethane dimethacrylates containing quaternary alkyl (C16, C12) ammonium and polyethylene glycol short sequences (Mn, 400 g/mol) and to investigate their behaviour in some experimental formulations in order to evaluate their potential applicability in the dental composites field. The structure of urethane dimethacrylates has been confirmed by (1)H ((13)C) NMR and FTIR spectra, as well as by electrospray ionization tandem mass spectroscopy, and gel permeation chromatography measurements. The effects of the cationic macromers on the properties of the filled/non-filled composites were examined through FTIR, photoDSC, and specific measurements as volumetric polymerization shrinkage, water sorption/solubility, contact angle, mechanical parameters, and morphology. The monomer compositions based on cationic dimethacrylate (6.88-27.52 wt%), BisGMA-analogue (48.18-68.82 wt%) and TEGDMA (23.3 wt%) showed a good photoreactivity in terms of double bond conversion (DC, 50.07-68.81 %) and polymerization rate (Rp, 0.099-0.141 s(-1)) measured by photoDSC compared to a control sample (BisGMA-1/TEGDMA: DC, 45.91 %; Rp, 0.162 s(-1)), while the polymerization shrinkage increased in acceptable limits (5.37-7.74 vol%). The mechanical properties (compressive, flexural and diametral tensile strength) of the composite resin incorporating 70 wt% silanized zirconium silicate micro/nanopowder can be modulated by the initial co-monomer concentrations. PMID:24435527

  14. Ammonium Hydrosulfide: Coloring Jupiter's Clouds

    NASA Astrophysics Data System (ADS)

    Loeffler, Mark J.; Hudson, Reggie L.; Chanover, Nancy J.; Simon, Amy A.

    2015-11-01

    The appearance and composition of Jupiter’s Great Red Spot (GRS) have been studied for over a century, yet there still is no consensus for what is causing the GRS’s color. As the GRS is believed to originate in tropospheric clouds, it seems likely that one or more cloud components may contribute to the GRS's color. Recently, we have begun to investigate whether either ammonium hydrosulfide (NH4SH), a predicted cloud component, or its radiation-chemical products can produce color and/or an ultraviolet-visible spectrum similar to what has been observed on Jupiter via remote sensing (e.g., Simon et al., 2015). Our initial experiments relied on infrared spectroscopy to quantify the radiolytic and thermal stability of NH4SH and to identify the new chemical products formed during MeV ion irradiation (Loeffler et al., 2015). This DPS presentation will cover some of our most recent results detailing the ultraviolet-visible spectral and color changes observed during irradiation and post-irradiation warming of NH4SH ices. This work is funded by NASA’s Outer Planets and Planetary Atmospheres programs.

  15. Phase diagram of ammonium nitrate

    SciTech Connect

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-12-07

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N{sub 2}, N{sub 2}O, and H{sub 2}O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV{sup ?} transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

  16. Monitoring personnel exposure to vinyl chloride, vinylidene chloride and methyl chloride in an industrial work environment.

    PubMed

    Severs, L W; Skory, L K

    1975-09-01

    Pittsburgh PCB 12 times 30 activated carbon is found to be the most suitable of the commerically available carbons tested for personnel sampling of vinyl chloride, vinylidene chloride, and methyl chloride. The carbon is desorbed with CS2 at dry ice temperature or with a thermal desorption technique. PMID:1180218

  17. Quaternary Science Reviews 24 (2005) 19631968 Quaternary coastal morphology and sea-level

    E-print Network

    Laughlin, Robert B.

    2005-01-01

    Quaternary Science Reviews 24 (2005) 1963­1968 Editorial Quaternary coastal morphology and sea-level timescales. The position of sea level (ultimate base level) and changes of sea level over geological geomorphological and environmental change in adjacent landscapes. Sea level determines the lower limit

  18. 77 FR 65532 - Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation: Notice of Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ...Administration [A-821-811] Solid Fertilizer Grade Ammonium Nitrate From the Russian...the antidumping duty order on solid fertilizer grade ammonium nitrate (ammonium nitrate...Antidumping Duty Administrative Review: Solid Fertilizer Grade Ammonium Nitrate (Ammonium...

  19. Effect of Application of Ammonium Chloride and Calcium Chloride on Alfalfa Cation-Anion Content and Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Periparturient hypocalcemia, or milk fever, occurs in dairy cattle when their dietary cation-anion difference (DCAD) is too high. DCAD can be favorably altered to prevent milk fever by either decreasing K and Na or increasing Cl and S in forages for cows in late gestation. The objective of this st...

  20. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...7783-20-2) occurs naturally and consists of colorless or white, odorless crystals or granules. It is prepared by the neutralization of sulfuric acid with ammonium hydroxide. (b) The ingredient meets the specifications of the “Food...

  1. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...7783-20-2) occurs naturally and consists of colorless or white, odorless crystals or granules. It is prepared by the neutralization of sulfuric acid with ammonium hydroxide. (b) The ingredient meets the specifications of the “Food...

  2. Biodegradation of rocket propellent waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqui, S. M. Z.

    1975-01-01

    The impact of the biodegradation rate of ammonium perchlorate on the environment was studied in terms of growth, metabolic rate, and total biomass of selected animal and plant species. Brief methodology and detailed results are presented.

  3. 21 CFR 184.1135 - Ammonium bicarbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...bicarbonate (NH4 HCO3 , CAS Reg. No. 1066-33-7) is prepared by reacting gaseous carbon dioxide with aqueous ammonia. Crystals of ammonium bicarbonate are precipitated from solution and subsequently washed and dried. (b) The ingredient...

  4. 21 CFR 184.1135 - Ammonium bicarbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...bicarbonate (NH4 HCO3 , CAS Reg. No. 1066-33-7) is prepared by reacting gaseous carbon dioxide with aqueous ammonia. Crystals of ammonium bicarbonate are precipitated from solution and subsequently washed and dried. (b) The ingredient...

  5. The Irish quaternary fauna project

    NASA Astrophysics Data System (ADS)

    Woodman, Peter; Mccarthy, Margaret; Monaghan, Nigel

    Much of Ireland's Pleistocene and Early Holocene mammalian faunas are derived from a series of late 19th/early 20th century cave excavations. In many instances it would appear that the deposits containing these faunal remains were disturbed. This project assessed the chronological range of the mammalian species present in the caves using 14C dating, in particular accelerator mass spectrometry (AMS). The research has shown that (1) a wide range of mammals colonised Ireland in the period between at least 45 ka and 20 ka, with some elements surviving until close to the Last Glacial Maximum; (2) a more restricted range of species re-colonised Ireland during the Lateglacial period, with evidence for a slightly more temperature fauna being replaced by an Arctic fauna at about 11 ka; (3) certain elements of Ireland's Holocene fauna may have survived through from the Lateglacial into the Holocene; (4) there is a lack of evidence for red deer, Cervus elaphus, being present in the Early Holocene in Ireland; and (5) horse is only documented in the Irish Holocene from 4 ka. The paper also discusses the implications of the Quaternary Fauna Project for the Late Pleistocene of Ireland, the mechanism and period of colonisation of Ireland as well as the introduction of domesticates in the Mid Holocene.

  6. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO...

  7. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed with..., blasting, type B, and Explosives, blasting, type E, Division 1.5 compatibility group D. (f) No...

  8. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed with..., blasting, type B, and Explosives, blasting, type E, Division 1.5 compatibility group D. (f) No...

  9. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed with..., blasting, type B, and Explosives, blasting, type E, Division 1.5 compatibility group D. (f) No...

  10. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed with..., blasting, type B, and Explosives, blasting, type E, Division 1.5 compatibility group D. (f) No...

  11. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed with..., blasting, type B, and Explosives, blasting, type E, Division 1.5 compatibility group D. (f) No...

  12. Oxomemazine hydro-chloride.

    PubMed

    Siddegowda, M S; Butcher, Ray J; Akkurt, Mehmet; Yathirajan, H S; Ramesh, A R

    2011-08-01

    IN THE TITLE COMPOUND [SYSTEMATIC NAME: 3-(5,5-dioxo-phen-othia-zin-10-yl)-N,N,2-trimethyl-propanaminium chloride], C(18)H(23)N(2)O(2)S(+)·Cl(-), the dihedral angle between the two outer aromatic rings of the phenothia-zine unit is 30.5?(2)°. In the crystal, the components are linked by N-H?Cl and C-H?Cl hydrogen bonds and C-H?? inter-actions. PMID:22090928

  13. Oxomemazine hydro­chloride

    PubMed Central

    Siddegowda, M. S.; Butcher, Ray J.; Akkurt, Mehmet; Yathirajan, H. S.; Ramesh, A. R.

    2011-01-01

    In the title compound [systematic name: 3-(5,5-dioxo­phen­othia­zin-10-yl)-N,N,2-trimethyl­propanaminium chloride], C18H23N2O2S+·Cl?, the dihedral angle between the two outer aromatic rings of the phenothia­zine unit is 30.5?(2)°. In the crystal, the components are linked by N—H?Cl and C—H?Cl hydrogen bonds and C—H?? inter­actions. PMID:22090928

  14. 40 CFR 721.10569 - Tricyclic quaternary amine salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Tricyclic quaternary amine salt (generic). 721.10569 Section 721...721.10569 Tricyclic quaternary amine salt (generic). (a) Chemical substance...generically as tricyclic quaternary amine salt (PMN P-08-471) is subject to...

  15. 40 CFR 721.10569 - Tricyclic quaternary amine salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tricyclic quaternary amine salt... Specific Chemical Substances § 721.10569 Tricyclic quaternary amine salt (generic). (a) Chemical substance... tricyclic quaternary amine salt (PMN P-08-471) is subject to reporting under this section for...

  16. 40 CFR 721.10569 - Tricyclic quaternary amine salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tricyclic quaternary amine salt... Specific Chemical Substances § 721.10569 Tricyclic quaternary amine salt (generic). (a) Chemical substance... tricyclic quaternary amine salt (PMN P-08-471) is subject to reporting under this section for...

  17. Calcium sulphate in ammonium sulphate solution

    USGS Publications Warehouse

    Sullivan, E.C.

    1905-01-01

    Calcium sulphate, at 25?? C., is two-thirds as soluble in dilute (o.i mol per liter) and twice as soluble in concentrated (3 mois per liter) ammonium sulphate solution as in water. The specific electric conductivity of concentrated ammonium sulphate solutions is lessened by saturating with calcium sulphate. Assuming that dissociation of ammonium sulphate takes place into 2NH4?? and SO4" and of calcium sulphate into Ca and SO4" only, and that the conductivity is a measure of such dissociation, the solubility of calcium sulphate in dilute ammonium sulphate solutions is greater than required by the mass-law. The conductivity of the dilute mixtures may be accurately calculated by means of Arrhenius' principle of isohydric solutions. In the data obtained in these calculations, the concentration of non-dissociated calcium sulphate decreases with increasing ammonium sulphate. The work as a whole is additional evidence of the fact that we are not yet in possession of all the factors necessary for reconciling the mass-law to the behavior of electrolytes. The measurements above described were made in the chemical laboratory of the University of Michigan.

  18. Catalytic enantioselective synthesis of quaternary carbon stereocentres

    NASA Astrophysics Data System (ADS)

    Quasdorf, Kyle W.; Overman, Larry E.

    2014-12-01

    Quaternary carbon stereocentres--carbon atoms to which four distinct carbon substituents are attached--are common features of molecules found in nature. However, before recent advances in chemical catalysis, there were few methods of constructing single stereoisomers of this important structural motif. Here we discuss the many catalytic enantioselective reactions developed during the past decade for the synthesis of single stereoisomers of such organic molecules. This progress now makes it possible to incorporate quaternary stereocentres selectively in many organic molecules that are useful in medicine, agriculture and potentially other areas such as flavouring, fragrances and materials.

  19. Catalytic Enantioselective Synthesis of Quaternary Carbon Stereocenters

    PubMed Central

    Quasdorf, Kyle W.; Overman, Larry E.

    2015-01-01

    Preface Quaternary carbon stereocenters–carbon atoms to which four distinct carbon substituents are attached–are common features of molecules found in nature. However, prior to recent advances in chemical catalysis, there were few methods available for constructing single stereoisomers of this important structural motif. Here we discuss the many catalytic enantioselective reactions developed during the past decade for synthesizing organic molecules containing such carbon atoms. This progress now makes it possible to selectively incorporate quaternary stereocenters in many high-value organic molecules for use in medicine, agriculture, and other areas. PMID:25503231

  20. 21 CFR 184.1297 - Ferric chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ferric chloride. 184.1297 Section 184.1297 Food... Specific Substances Affirmed as GRAS § 184.1297 Ferric chloride. (a) Ferric chloride (iron (III) chloride... hydrogen chloride. The pure material occurs as hydroscopic, hexagonal, dark crystals. Ferric...

  1. 21 CFR 184.1297 - Ferric chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ferric chloride. 184.1297 Section 184.1297 Food... Specific Substances Affirmed as GRAS § 184.1297 Ferric chloride. (a) Ferric chloride (iron (III) chloride... hydrogen chloride. The pure material occurs as hydroscopic, hexagonal, dark crystals. Ferric...

  2. 21 CFR 184.1297 - Ferric chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ferric chloride. 184.1297 Section 184.1297 Food... Specific Substances Affirmed as GRAS § 184.1297 Ferric chloride. (a) Ferric chloride (iron (III) chloride... hydrogen chloride. The pure material occurs as hydroscopic, hexagonal, dark crystals. Ferric...

  3. 21 CFR 184.1297 - Ferric chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ferric chloride. 184.1297 Section 184.1297 Food... GRAS § 184.1297 Ferric chloride. (a) Ferric chloride (iron (III) chloride, FeC13, CAS Reg. No. 7705-08-0) may be prepared from iron and chlorine or from ferric oxide and hydrogen chloride. The...

  4. Arctic climates of the Quaternary

    NASA Astrophysics Data System (ADS)

    Spielhagen, R. F.; Bauch, H. A.; Frank, M.; Haley, B. A.

    2009-04-01

    The Atlantic Water (AW) inflow through the Fram Strait and across the Barents Sea and the freshwater runoff and brine rejection from sea ice formation on and close to the surrounding shelves are important processes for the formation of modern water masses in the interior Arctic Ocean. From microfossil and sedimentological data, isotopic data from planktic and benthic foraminifers, and 143Nd/144Nd ratios in leached sediment coatings from several well-dated Arctic sediment cores it is possible to reconstruct the variable influence of both processes on surface and intermediate waters in the Late Quaternary. Interglacials and interstadials were characterized by a broken sea ice cover with some open waters (leads) and a strong subsurface AW advection of Atlantic Water, feeding the deeper water masses. During the last ca. 250 ky such events usually were of a relatively short duration (10 ky or less), at times when the northern Eurasian shelves were ice-free. An exception is the last 50 ky interval, when a continuous inflow is recorded. Low Nd ratios indicate also a strong AW contribution to the intermediate waters since 50 ka and during MIS 5e. This conclusion is corroborated by high benthic carbon isotope values, indicative of well-ventilated waters at ca. 1500 m water depth. The good correlation between microfossil contents and insolation values suggests a dominant solar control of the AW inflow history. The time intervals of extended glaciations in northern Eurasia at ca. 190-130, 80-90, and 50-60 ka were characterized by a weak or lacking AW inflow and a strong input of terrestrial ice-rafted debris (IRD). Deglaciations were marked by strong influxes of freshwater from melting ice sheets and/or discharges from previously ice-dammed lakes. High Nd ratios indicate a significant contribution of brines from northern Siberian shelf/ice sheet margins to intermediate waters on the Lomonosov Ridge. The strongest freshwater events occurred at ca. 130 and 52 ka and resulted in an enhanced stratification of the upper water masses and poorly ventilated halocline and deep waters. While sediment records from the northernmost North Atlantic indicate a trend towards warmer peak interglacials and lesser IRD input during peak glacials in the last 500 ky, Arctic records do not reveal such a development. First strong IRD input occurred only during the Saalian glaciation, while earlier and even more extensive glaciations in northern Asia probably did not reach the Arctic paleo-coastline.

  5. Synthesis of Tertiary and Quaternary Amine Derivatives from Wood Resin as Chiral NMR Solvating Agents.

    PubMed

    Laaksonen, Tiina; Heikkinen, Sami; Wähälä, Kristiina

    2015-01-01

    Chiral tertiary and quaternary amine solvating agents for NMR spectroscopy were synthesized from the wood resin derivative (+)-dehydroabietylamine (2). The resolution of enantiomers of model compounds [Mosher's acid (3) and its n-Bu?N salt (4)] (guests) by (+)-dehydroabietyl-N,N-dimethylmethanamine (5) and its ten different ammonium salts (hosts) was studied. The best results with 3 were obtained using 5 while with 4 the best enantiomeric resolution was obtained using (+)-dehydroabietyl-N,N-dimethylmethanaminium bis(trifluoromethane-sulfonimide) (6). The compounds 5 and 6 showed a 1:1 complexation behaviour between the host and guest. The capability of 5 and 6 to recognize the enantiomers of various ?-substituted carboxylic acids and their n-Bu?N salts in enantiomeric excess (ee) determinations was demonstrated. A modification of the RES-TOCSY NMR pulse sequence is described, allowing the enhancement of enantiomeric discrimination when the resolution of multiplets is insufficient. PMID:26610454

  6. On the evaporation of ammonium sulfate solution

    SciTech Connect

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-07-16

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

  7. On the evaporation of ammonium sulfate solution

    PubMed Central

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-01-01

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 ± 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor–liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly. PMID:19861551

  8. Evaluation of 0.1% ammonium hydroxide to replace sodium tripolyphosphate in fresh meat injection brines.

    PubMed

    Cerruto-Noya, C A; VanOverbeke, D L; DeWitt, C A Mireles

    2009-09-01

    Paired USDA Select beef strip loins (n = 10), aged 2 d, were injected with either an alkaline-based (3.6% sodium chloride, 1% Herbalox seasoning, adjusted to pH 10 with ammonium hydroxide [approximately 0.1%, FFC grade]) or a phosphate-based (3.6% sodium chloride, 1% Herbalox seasoning, 4.5% sodium tripolyphosphate) brine. Steaks were evaluated for 19 d. Overall, phosphate-injected steaks performed better than alkaline-injected steaks with respect to cook yield, water holding capacity, lipid oxidation, color stability, tenderness, and juiciness. Phosphate-injected steaks also had less purge than alkaline-injected steaks, as confirmed by composition analysis. Phosphate-injected steaks were higher in moisture and ash content, and were nearly 2% lower in protein content. Alkaline-injected steaks had significantly lower aerobic (approximately 1 log lower) and anaerobic (approximately 2 log lower) plate counts. Final meat pH probably contributed to the differences observed between treatments. The final pH of phosphate-injected steak was 5.99 while that of alkaline-injected steak was 5.73. Further research should be conducted to determine the concentration of ammonium hydroxide needed in the alkaline-based brine to increase the final meat pH to similar levels found in the phosphate-injected steaks. PMID:19895455

  9. Examples Class 2 Calcium Chloride

    E-print Network

    Cambridge, University of

    Examples Class 2 Calcium Chloride The orthorhombic unit cell of CaCl2 has a = 0.624 nm, b = 0 of this structure on (001). Figure 1: The structure projection for cal- cium chloride 1. What is the Bravais lattice

  10. Quaternary Geochronology 1 (2006) 7485 Research paper

    E-print Network

    Briner, Jason P.

    2006-01-01

    of complete shielding by the LIS. The lack of glacial erosion for at least the past 400 kyr suggests Island; Glacial history; Interglaciation; Erosion 1. Introduction The large-scale physiography of BaffinQuaternary Geochronology 1 (2006) 74­85 Research paper Limited ice-sheet erosion and complex

  11. Enantioselective construction of remote quaternary stereocentres

    NASA Astrophysics Data System (ADS)

    Mei, Tian-Sheng; Patel, Harshkumar H.; Sigman, Matthew S.

    2014-04-01

    Small molecules that contain all-carbon quaternary stereocentres--carbon atoms bonded to four distinct carbon substituents--are found in many secondary metabolites and some pharmaceutical agents. The construction of such compounds in an enantioselective fashion remains a long-standing challenge to synthetic organic chemists. In particular, methods for synthesizing quaternary stereocentres that are remote from other functional groups are underdeveloped. Here we report a catalytic and enantioselective intermolecular Heck-type reaction of trisubstituted-alkenyl alcohols with aryl boronic acids. This method provides direct access to quaternary all-carbon-substituted ?-, ?-, ?-, ?- or ?-aryl carbonyl compounds, because the unsaturation of the alkene is relayed to the alcohol, resulting in the formation of a carbonyl group. The scope of the process also includes incorporation of pre-existing stereocentres along the alkyl chain, which links the alkene and the alcohol, in which the stereocentre is preserved. The method described allows access to diverse molecular building blocks containing an enantiomerically enriched quaternary centre.

  12. 21 CFR 173.255 - Methylene chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Methylene chloride. 173.255 Section 173.255 Food and Drugs...and Related Substances § 173.255 Methylene chloride. Methylene chloride may be present in food under the following...

  13. 21 CFR 173.255 - Methylene chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Methylene chloride. 173.255 Section 173.255 Food and Drugs...and Related Substances § 173.255 Methylene chloride. Methylene chloride may be present in food under the following...

  14. 21 CFR 173.375 - Cetylpyridinium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Cetylpyridinium chloride. 173.375 Section 173.375 Food and...Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No. 123-93-5) may be...

  15. 21 CFR 582.3845 - Stannous chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Stannous chloride. 582.3845 Section 582.3845 Food...Chemical Preservatives § 582.3845 Stannous chloride. (a) Product. Stannous chloride. (b) Tolerance. This substance...

  16. 21 CFR 173.255 - Methylene chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Methylene chloride. 173.255 Section 173.255 Food and Drugs...and Related Substances § 173.255 Methylene chloride. Methylene chloride may be present in food under the following...

  17. 21 CFR 582.5446 - Manganese chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food...Dietary Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use. This...

  18. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of...

  19. 21 CFR 173.375 - Cetylpyridinium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Cetylpyridinium chloride. 173.375 Section 173.375 Food and...Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No. 123-03-05) may be...

  20. 21 CFR 173.375 - Cetylpyridinium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Cetylpyridinium chloride. 173.375 Section 173.375 Food and...Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No. 123-93-5) may be...

  1. 21 CFR 173.255 - Methylene chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Methylene chloride. 173.255 Section 173.255 Food and Drugs...and Related Substances § 173.255 Methylene chloride. Methylene chloride may be present in food under the following...

  2. 21 CFR 582.5622 - Potassium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Potassium chloride. 582.5622 Section 582.5622 Food...Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

  3. 21 CFR 582.3845 - Stannous chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Stannous chloride. 582.3845 Section 582.3845 Food...Chemical Preservatives § 582.3845 Stannous chloride. (a) Product. Stannous chloride. (b) Tolerance. This substance...

  4. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of...

  5. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Dimethyldialkylammonium chloride. 173.400 Section 173.400 Food and...Additives § 173.400 Dimethyldialkylammonium chloride. Dimethyldialkylammonium chloride may be safely used in food in accordance...

  6. 21 CFR 582.5622 - Potassium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Potassium chloride. 582.5622 Section 582.5622 Food...Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

  7. 75 FR 33824 - Barium Chloride From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-15

    ...731-TA-149 (Third Review)] Barium Chloride From China Determination On the basis...the antidumping duty order on barium chloride from China would be likely to lead to...4157 (June 2010), entitled Barium Chloride from China: Investigation No....

  8. 21 CFR 582.5622 - Potassium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Potassium chloride. 582.5622 Section 582.5622 Food...Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

  9. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2009-04-01 true Dimethyldialkylammonium chloride. 173.400 Section 173.400 Food and...Additives § 173.400 Dimethyldialkylammonium chloride. Dimethyldialkylammonium chloride may be safely used in food in accordance...

  10. 21 CFR 173.255 - Methylene chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Methylene chloride. 173.255 Section 173.255 Food and Drugs...and Related Substances § 173.255 Methylene chloride. Methylene chloride may be present in food under the following...

  11. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of...

  12. 21 CFR 173.375 - Cetylpyridinium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Cetylpyridinium chloride. 173.375 Section 173.375 Food and...Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No. 123-93-5) may be...

  13. 75 FR 19657 - Barium Chloride From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-15

    ...731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States International...the antidumping duty order on barium chloride from China...the antidumping duty order on barium chloride from China would be likely to lead...

  14. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Dimethyldialkylammonium chloride. 173.400 Section 173.400 Food and...Additives § 173.400 Dimethyldialkylammonium chloride. Dimethyldialkylammonium chloride may be safely used in food in accordance...

  15. 21 CFR 582.3845 - Stannous chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Stannous chloride. 582.3845 Section 582.3845 Food...Chemical Preservatives § 582.3845 Stannous chloride. (a) Product. Stannous chloride. (b) Tolerance. This substance...

  16. 21 CFR 173.375 - Cetylpyridinium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2009-04-01 true Cetylpyridinium chloride. 173.375 Section 173.375 Food and...Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No. 123-03-05) may be...

  17. 21 CFR 582.5446 - Manganese chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food...Dietary Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use. This...

  18. 21 CFR 582.5446 - Manganese chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food...Dietary Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use. This...

  19. 21 CFR 582.5622 - Potassium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Potassium chloride. 582.5622 Section 582.5622 Food...Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

  20. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Dimethyldialkylammonium chloride. 173.400 Section 173.400 Food and...Additives § 173.400 Dimethyldialkylammonium chloride. Dimethyldialkylammonium chloride may be safely used in food in accordance...

  1. 21 CFR 582.5622 - Potassium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Potassium chloride. 582.5622 Section 582.5622 Food...Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

  2. 21 CFR 582.5446 - Manganese chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food...Dietary Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use. This...

  3. 21 CFR 582.3845 - Stannous chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Stannous chloride. 582.3845 Section 582.3845 Food...Chemical Preservatives § 582.3845 Stannous chloride. (a) Product. Stannous chloride. (b) Tolerance. This substance...

  4. 21 CFR 582.5446 - Manganese chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food...Dietary Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use. This...

  5. 21 CFR 173.400 - Dimethyldialkylammonium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Dimethyldialkylammonium chloride. 173.400 Section 173.400 Food and...Additives § 173.400 Dimethyldialkylammonium chloride. Dimethyldialkylammonium chloride may be safely used in food in accordance...

  6. 21 CFR 582.3845 - Stannous chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Stannous chloride. 582.3845 Section 582.3845 Food...Chemical Preservatives § 582.3845 Stannous chloride. (a) Product. Stannous chloride. (b) Tolerance. This substance...

  7. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Agriculture 3 2010-01-01 2010-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Quality Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the...

  8. 7 CFR 58.434 - Calcium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Agriculture 3 2011-01-01 2011-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture...Quality Specifications for Raw Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the...

  9. Flow and morphological conditions associated with the directional solidification of aqueous ammonium chloride. Annual performance report

    SciTech Connect

    Magirl, C.S.; Incropera, F.P.

    1993-01-01

    Using 27% aq. NH{sub 4}Cl solutions as transparent analog, shadowgraphy and dye injection were used to observe flow and morphology in unidirectional solidification (UDS) from below. Dendritic crystals that form at the cold surface reject lighter, solute-deficient fluid, and instability is shown by finger-type double-diffusive convection. As the mushy two-phase region grows, perturbations at the liquidus interface cause localized remelting and downward development of channels. Solsutal plumes emanate from the channels, and in time, double-diffusive convection layers also form in the melt. When the solution is chilled at the sides as well as at the bottom, conditions are influenced by detachment and settling of crystals from the sidewall and by plumes from slanted channels. When a slow, oscillatory rocking motion is imposed on UDS, the freckle-type segregates in the final cast is suppressed. Within the melt, plumes and double-diffusive convection are eliminated. Inertially induced convection mixes the melt and produces a dense slurry. Although channels are eliminated from the bottom mushy region, overall heat transfer and macrosegregation in the cavity are unaffected by the slow rocking. Numerical simulations qualitatively predict trends in the field variables and provide insights on interdendritic flows and macrosegregation (freckle-, A-type segregates), although its quantitative predictions are hampered by simplifying assumptions.

  10. Surface tension measurements of aqueous ammonium chloride (NH4Cl) in air

    NASA Technical Reports Server (NTRS)

    Lowry, S. A.; Mccay, M. H.; Mccay, T. D.; Gray, P. A.

    1989-01-01

    Aqueous NH4Cl's solidification is often used to model metal alloy solidification processes. The present determinations of the magnitude of the variation of aqueous NH4Cl's surface tension as a function of both temperature and solutal concentration were conducted at 3, 24, and 40 C over the 72-100 wt pct water solutal range. In general, the surface tension increases 0.31 dyn/cm per percent decrease in wt pct of water, and decreases 0.13 dyn/cm for each increase in deg C. Attention is given to the experimental apparatus employed.

  11. Aggregation and chimney formation during the solidification of ammonium chloride T. H. Solomon,* R. R. Hartley,

    E-print Network

    Solomon, Tom

    . In particular a solid-liquid mixture ``mushy layer'' forms in which growing solid NH4Cl crystals form a solid flows that carry seed crystals from the upper cold boundary to the warmer side and bottom boundaries. Ballistic deposition of these seed crystals leads to aggregation patterns with significant voids filled

  12. An in vivo microperfusion study of distal tubule bicarbonate reabsorption in normal and ammonium chloride rats.

    PubMed Central

    Levine, D Z

    1985-01-01

    For many years it has been thought that distal nephron hydrogen ion secretion can be importantly modulated by factors such as sodium delivery, sodium avidity, and potassium stores. Free flow micropuncture studies have also indicated that the rate of bicarbonate delivery may also alter the rate of bicarbonate reabsorption. The present studies were undertaken to examine possible luminal influences on total CO2 reabsorption in microperfused distal tubules in the rat in vivo. Tubules from normal and acidotic rats were perfused with five solutions in a manner that induced changes in bicarbonate load, sodium and potassium fluxes (JNa, JK), and luminal sulfate concentration. in each collected perfusate, simultaneous analyses were undertaken to determine water reabsorption, Na, and K concentrations using graphite furnace atomic absorption spectroscopy and total CO2 by microcalorimetry. Using factorial analysis of covariance to account for confounding effects on total CO2 flux (JtCO2) such as water reabsorption, distal tubules of acidotic rats reabsorbed CO2 in the range of 50-112 pmol X min-1 X mm-1 X These JtCO2 values were not significantly correlated with HCO3 load, JNa, or JK despite changes in the latter from net reabsorption to net secretion. Distal tubules of rats with normal acid-base status had JtCO2 values which were neither significantly different from zero nor correlated with changes in JK and JNa. Further, doubling the load from 250-500 pmol/min (by doubling the perfusion rate of 25-mM HCO3 solutions) did not stimulate JtCO2 in these normal animals. Accordingly, these acute in vivo microperfusion studies indicate for the first time that neither load nor potassium or sodium fluxes are important modulators of distal tubule bicarbonate reabsorption. PMID:2982915

  13. Ammonium chloride complex formation during downstream microwave ammonia plasma treatment of parylene-C

    SciTech Connect

    Pruden, K.G.; Beaudoin, S.P.

    2005-11-15

    In this work, parylene-C is exposed to the effluent from a microwave ammonia plasma with a goal of producing primary amine groups on the parylene-C. These amine groups are desired as sites for the attachment of various biomolecules that will influence the biocompatibility of the parylene-C. Ammonia plasma treatment is an effective approach for creating amine species on polymers. In this work, attenuated total reflectance infrared spectroscopy studies showed that no primary amine groups resulted from this treatment of parylene-C. Instead, reactive nitrogen-bearing radicals from the plasma appear to have been complexed by chlorine in the polymer. The formation of these complexes scavenged nitrogen-bearing radicals from the plasma and prevented the formation of nitrogenous species, such as the desired primary amines, on the parylene-C. These results are consistent with results of ammonia plasma treatment of other chlorinated polymers and suggest that alternative approaches are required to create nitrogen-bearing species on parylene-C.

  14. Flow and morphological conditions associated with the directional solidification of aqueous ammonium chloride

    SciTech Connect

    Magirl, C.S.; Incropera, F.P.

    1993-01-01

    Using 27% aq. NH[sub 4]Cl solutions as transparent analog, shadowgraphy and dye injection were used to observe flow and morphology in unidirectional solidification (UDS) from below. Dendritic crystals that form at the cold surface reject lighter, solute-deficient fluid, and instability is shown by finger-type double-diffusive convection. As the mushy two-phase region grows, perturbations at the liquidus interface cause localized remelting and downward development of channels. Solsutal plumes emanate from the channels, and in time, double-diffusive convection layers also form in the melt. When the solution is chilled at the sides as well as at the bottom, conditions are influenced by detachment and settling of crystals from the sidewall and by plumes from slanted channels. When a slow, oscillatory rocking motion is imposed on UDS, the freckle-type segregates in the final cast is suppressed. Within the melt, plumes and double-diffusive convection are eliminated. Inertially induced convection mixes the melt and produces a dense slurry. Although channels are eliminated from the bottom mushy region, overall heat transfer and macrosegregation in the cavity are unaffected by the slow rocking. Numerical simulations qualitatively predict trends in the field variables and provide insights on interdendritic flows and macrosegregation (freckle-, A-type segregates), although its quantitative predictions are hampered by simplifying assumptions.

  15. Hydrometallurgical extraction of zinc from CaO treated EAF dust in ammonium chloride solution.

    PubMed

    Miki, Takahiro; Chairaksa-Fujimoto, Romchat; Maruyama, Katsuya; Nagasaka, Tetsuya

    2016-01-25

    Zinc in Electric Arc Furnace dust or EAF dust mainly exists as ZnFe2O4 and ZnO. While ZnO can be simply dissolved into either an acidic or alkaline solution, it is difficult to dissolve ZnFe2O4. In our previous work, we introduced a process called "CaO treatment", a preliminary pyrometallurgical process designed to transform the ZnFe2O4 in the EAF dust into ZnO and Ca2Fe2O5. The halogens and others heavy metals were favorably vaporized during CaO treatment with no essential evaporation loss of zinc and iron, leaving CaO treated dust which consisted mainly of ZnO and Ca2Fe2O5 and no problematic ZnFe2O4 compound. In this work, the selective leaching of zinc over iron and calcium in the CaO treated dust was investigated using an NH4Cl solution. The effects of temperature, reaction time and NH4Cl concentration on dissolution behavior were examined. While most of the zinc in the CaO treated dust was extracted after 2h at 70°C with 2M NH4Cl, only about 20% of calcium was leached in NH4Cl solution. However, the iron did not dissolve and remained as Ca2Fe2O5 in residue. It was confirmed that zinc can be effectively recovered using NH4Cl solution. PMID:26448494

  16. Influence of cetyltrimethyl ammonium bromide on nutrient uptake and cell responses of Chlorella vulgaris.

    PubMed

    Liang, Zhijie; Ge, Fei; Zeng, Hui; Xu, Yin; Peng, Fang; Wong, Minghung

    2013-08-15

    The removal of nutrients by algae is regarded as a vital process in wastewater treatment, however algal cell activity can be inhibited by some toxic chemicals during the biological process. This study investigated the uptake of ammonia nitrogen (NH??) and total phosphorus (TP) by a green alga (Chlorella vulgaris) and algal cell responses under the stress of cetyltrimethyl ammonium bromide (CTAB), a representative for quaternary ammonium compounds (QACs, cationic surfactants). When the concentration of CTAB increased from 0 to 0.6 mg/L, the uptake efficiencies of NH?? and TP decreased from 88% to 18% and from 96% to 15%, respectively. Algal cell responses showed a decline in photosynthesis activity as indicated by the increase of chlorophyll autofluorescence from 2.9 a.u. to 25.3 a.u.; and a decrease of cell viability from 88% to 51%; and also a drop in esterase activity as indicated by the decrease in fluorescence of fluorescein diacetate stained cells from 71.5 a.u. to 4.7 a.u. Additionally, a transcription and translation response was confirmed by an enhancement of PO peak and amide II peak in algal cellular macromolecular composition stimulated by CTAB. The results suggest that QACs in wastewater may inhibit nutrient uptake by algae significantly through declining algal cell activities. PMID:23721850

  17. Diamond Head Revisited with Ammonium Dichromate.

    ERIC Educational Resources Information Center

    Arrigoni, Edward

    1981-01-01

    The classroom demonstration using ammonium dichromate to simulate a volcanic eruption can be modified into a more dramatic and accurate representation of the geologic processes involved in the formation of a volcanic crater. The materials, demonstration setup, safety procedures, and applications to instruction are presented. (Author/WB)

  18. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... is manufactured by the reaction of 99.5 percent ammonia gas and 99 percent formic acid in a... safe use of the additive, in addition to the other information required by the Federal Food, Drug, and... ammonium formate. (d) To assure safe use of the additive, in addition to the other information required...

  19. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) The additive is manufactured by the reaction of 99.5 percent ammonia gas and 99 percent formic acid in...) To assure safe use of the additive, in addition to the other information required by the Federal Food... labeled as containing ammonium formate. (d) To assure safe use of the additive, in addition to the...

  20. 76 FR 70366 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ... Department previously announced a series of public meetings on the same topic on October 2, 2011 (see 76 FR... public comment on August 3, 2011. See 73 FR 64280 (advance notice of proposed rulemaking); 76 FR 46908... the Department's Ammonium Nitrate Security Program Web site, at...