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Sample records for benzalkonium chloride susceptibility

  1. Effect of Oxygen Limitation and Starvation on the Benzalkonium Chloride Susceptibility of Escherichia coli

    DEFF Research Database (Denmark)

    Bjergbæk, L.A.; Haagensen, Janus Anders Juul; Molin, Søren

    2008-01-01

    Aims: To investigate the effect of oxygen limitation, glucose-starvation and temperature on the susceptibility of Escherichia coli towards the quaternary ammonium biocide benzalkonium chloride (BAC). Methods and Results: The effect of BAC on planktonic and sessile cells were investigated using...

  2. Antibiotic susceptibility in benzalkonium chloride-resistant and -susceptible Listeria monocytogenes strains.

    Science.gov (United States)

    Ortiz, Sagrario; López, Pilar; López, Victoria; Martínez-Suárez, Joaquín V

    2014-07-01

    This study aimed to investigate whether Listeria monocytogenes strains with resistance to a commonly used biocide display any cross-resistance to antibiotics. Using pulsed-field gel electrophoresis (PFGE), 29 different PFGE types were previously identified in an Iberian pig abattoir and processing plant. Only three PFGE types were resistant to benzalkonium chloride (BAC), but they represented a significant proportion of the PFGE types surviving in the plant after 4 years. In the present study, a subset of 29 strains, representing the 29 different PFGE types, underwent antibiotic susceptibility testing. Antibiotic susceptibility was assessed by Etest, utilizing 12 commonly prescribed antibiotics. All of the 29 strains were susceptible to all of the antibiotics tested. The study revealed that this group of different PFGE types of L. monocytogenes, including those resistant to BAC, possesses uniform sensitivity to antibiotics.

  3. Listeria monocytogenes Strains Selected on Ciprofloxacin or the Disinfectant Benzalkonium Chloride Exhibit Reduced Susceptibility to Ciprofloxacin, Gentamicin, Benzalkonium Chloride, and Other Toxic Compounds▿

    Science.gov (United States)

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

    2011-01-01

    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 μg/ml) or the quaternary ammonium disinfectant benzalkonium chloride (BC; 10 μg/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

  4. Benzalkonium Chloride and Glaucoma

    OpenAIRE

    Rasmussen, Carol A.; Kaufman, Paul L.; Kiland, Julie A.

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapo...

  5. Survival and susceptibility of Burkholderia cepacia complex in chlorhexidine gluconate and benzalkonium chloride.

    Science.gov (United States)

    Kim, Jeong Myeong; Ahn, Youngbeom; LiPuma, John J; Hussong, David; Cerniglia, Carl E

    2015-06-01

    The Burkholderia cepacia complex (BCC) includes opportunistic pathogenic bacteria that have occasionally been recovered from various pharmaceutical products, including antiseptics and disinfectants. Plausible reasons for the contamination include intrinsic sources, such as inadequate process controls, especially for water or equipment used during product manufacture, or extrinsic sources, such as improper handling and dilution or distribution in contaminated containers. Because the survival of BCC in antiseptics is a concern to the public health and pharmaceutical industry, we determined minimum inhibitory concentrations (MICs) of 36 BCC strains against the antiseptics, following exposure to chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) solutions (1-500 µg/ml for each chemical). Susceptibility to CHX and BZK varied across the BCC strains and was recorded as mean 90.3 and 111.1 µg/ml, respectively, at initial inoculation, which was significantly higher than the 46.4 and 61.1 µg/ml levels measured for BCC incubated in water for 40 days. After determining antiseptic MICs of individual BCC strains, BCC recovery was measured on Tryptic Soy Agar (TSA), Reasoner's Second Agar (R2A) and diluted preparations of these media under their sub-MICs. The survival of BCC was monitored for 14 days (336 h) in sub-MICs diluted to less than their antiseptic susceptible concentration value. Diluted TSA and R2A media exhibited greater efficiency of recovery for most BCC strains from the CHX and BZK solutions than full strength TSA or R2A. For BCC survival in antiseptic solutions, the cell number of BCC decreased rapidly within the first 20 min in both antiseptics, but after this, recovery remained constant in CHX and increased in BZK over the 14 day incubation period. The results indicate that BCC in water can remain viable with low susceptibility to antiseptics for 14 days, which suggests the necessity for improved detection methods and control measures to monitor

  6. Benzalkonium chloride and glaucoma.

    Science.gov (United States)

    Rasmussen, Carol A; Kaufman, Paul L; Kiland, Julie A

    2014-01-01

    Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology.

  7. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    OpenAIRE

    Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

    2012-01-01

    Topical application of benzalkonium chloride (BAK) to the eye causes dose-related corneal neurotoxicity. Corneal inflammation and reduction in aqueous tear production accompany neurotoxicity. Cessation of BAK treatment leads to recovery of corneal nerve density.

  8. EVALUATION OF BACTERICIDAL EFFECTIVENESS OF BENZALKONIUM CHLORIDE

    Directory of Open Access Journals (Sweden)

    K. Imandel

    1996-06-01

    Full Text Available Benzalkonium chloride is a quaternary ammounium Compounds derivative under different names such as Afxhang, Hamoon, Mahan etc, which have great and expanded use in sanitation and medical affairs. Bactericidal activity of these disinfectants was fulfilled according to National Standard Method No.2842 on Staph. Aureus, Sal. Typhimouium and E. coli. This laboratory test showed that, except Mahan that has not bactericidal efficacy on E.coli at concentration 0.4 percent, other disinfectants under the study in concentrations of 0.4, 0.8, 1, 1.2 percent have reliable antibacterial properties, and bacterial resistance to benzalkonium chloride has not occurred yet.

  9. Aspergilli Response to Benzalkonium Chloride and Novel-Synthesized Fullerenol/Benzalkonium Chloride Nanocomposite

    OpenAIRE

    Nikola Unković; Milica Ljaljević Grbić; Miloš Stupar; Jelena Vukojević; Vesna Janković; Danica Jović; Aleksandar Djordjević

    2015-01-01

    A comprehensive comparative analysis of antifungal potential of benzalkonium chloride and newly synthesized fullerenol/benzalkonium chloride nanocomposite was conducted to assess the possible impact of carbon-based nanocarrier on antimicrobial properties of the commonly used biocide. Physical characterization of synthesized nanocomposite showed zeta potential of +37.4 mV and inhomogeneous particles size distribution, with nanocomposite particles’ dimensions within 30–143 nm and maximum number...

  10. Aspergilli Response to Benzalkonium Chloride and Novel-Synthesized Fullerenol/Benzalkonium Chloride Nanocomposite.

    Science.gov (United States)

    Unković, Nikola; Ljaljević Grbić, Milica; Stupar, Miloš; Vukojević, Jelena; Janković, Vesna; Jović, Danica; Djordjević, Aleksandar

    2015-01-01

    A comprehensive comparative analysis of antifungal potential of benzalkonium chloride and newly synthesized fullerenol/benzalkonium chloride nanocomposite was conducted to assess the possible impact of carbon-based nanocarrier on antimicrobial properties of the commonly used biocide. Physical characterization of synthesized nanocomposite showed zeta potential of +37.4 mV and inhomogeneous particles size distribution, with nanocomposite particles' dimensions within 30-143 nm and maximum number of particles at 44 nm. The effect of pure and fullerenol nanocarrier-bound biocide was evaluated in eight Aspergillus species. In mycelial growth assay, nanocomposite was more potent, as fungicidal effect of 1.04/0.6 μg mL(-1) was obtained in all but one of the isolates (A. niger), while proportional concentration of pure biocide (0.6 μg mL(-1)) completely inhibited mycelial growth of only three Aspergillus species. However, conidia appear to be less susceptible to nanocomposite treatment, as lower fungistatic (MIC) and fungicidal (MFC) concentrations were obtained with biocide alone (MIC in range from 0.03 to 0.15 μg mL(-1) and MFC from 0.075 to 0.45 μg mL(-1)). To a different degree, both substances stimulated aflatoxin B1 production and inhibited ochratoxin A synthesis. Very low mycelium biomass yield, in range from 1.0 to 3.0 mg dry weight, was documented in both biocide and nanocomposite enriched medium.

  11. Mechanism of resistance to benzalkonium chloride by Pseudomonas aeruginosa.

    OpenAIRE

    Sakagami, Y; Yokoyama, H; Nishimura, H.; Ose, Y; Tashima, T.

    1989-01-01

    The mechanisms of resistance of Pseudomonas aeruginosa to benzalkonium chloride (BC) were studied. The effluence of cell components was observed in susceptible P. aeruginosa by electron microscopy, but resistant P. aeruginosa seemed to be undamaged. No marked changes in cell surface potential between Escherichia coli NIHJC-2 and a spheroplast strain were found. The contents of phospholipids (PL) and fatty and neutral lipids (FNL) in the cell walls of resistant P. aeruginosa were higher than t...

  12. Benzalkonium chloride. Health hazard evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    OpenAIRE

    Güler, Ekrem; Olgar, Şeref; Davutoğlu, Mehmet; Garipardıç, Mesut; Karabiber, Hamza

    2011-01-01

    Benzalkonium chloride (BAC) is a frequently used disinfectant and its most well-known side effect is contact dermatitis. In this report, two children who had vesicular dermatitis, headache, lethargy, fever and encephalopathy mimicking Herpes zoster encephalitis were presented. Their consciousness level improved on the second day. From the medical history it was understood that the mother had applied 20% BAC solution to the scalps of two children. The aim of the presentation of this report is ...

  14. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    OpenAIRE

    Ekrem Güler; Şeref Olgar; Mehmet Davutoğlu; Mesut Garipardıç; Hamza Karabiber

    2014-01-01

    Benzalkonium chloride (BAC) is a frequently used disinfectant and its most well-known side effect is contact dermatitis. In this report, two children who had vesicular dermatitis, headache, lethargy, fever and encephalopathy mimicking Herpes zoster encephalitis were presented. Their consciousness level improved on the second day. From the medical history it was understood that the mother had applied 20% BAC solution to the scalps of two children. The aim of the presentation of this report is...

  15. EVALUATION OF BACTERICIDAL EFFECTIVENESS OF BENZALKONIUM CHLORIDE

    OpenAIRE

    K. Imandel; M.B. Shaywaard; F. Mobaraki

    1996-01-01

    Benzalkonium chloride is a quaternary ammounium Compounds derivative under different names such as Afxhang, Hamoon, Mahan etc, which have great and expanded use in sanitation and medical affairs. Bactericidal activity of these disinfectants was fulfilled according to National Standard Method No.2842 on Staph. Aureus, Sal. Typhimouium and E. coli. This laboratory test showed that, except Mahan that has not bactericidal efficacy on E.coli at concentration 0.4 percent, other disinfectants under ...

  16. Inactivation of Viruses by Benzalkonium Chloride

    Science.gov (United States)

    Armstrong, J. A.; Froelich, E. J.

    1964-01-01

    Benzalkonium chloride (as Roccal or Zephiran) was found to inactivate influenza, measles, canine distemper, rabies, fowl laryngotracheitis, vaccinia, Semliki Forest, feline pneumonitis, meningopneumonitis, and herpes simplex viruses after 10 min of exposure at 30 C or at room temperature. Poliovirus and encephalomyocarditis virus were not inactivated under the same conditions. It was concluded that all viruses tested were sensitive except members of the picorna group. The literature was reviewed. PMID:4288740

  17. Resistant mechanism study of benzalkonium chloride selected Salmonella Typhimurium mutants.

    Science.gov (United States)

    Guo, Wei; Cui, Shenghui; Xu, Xiao; Wang, Haoyan

    2014-02-01

    Benzalkonium chloride is one of the invaluable biocides that is extensively used in healthcare settings as well as in the food processing industry. After exposing wild-type Salmonella Typhimurium 14028s or its AcrAB inactivation mutant to gradually increasing levels of benzalkonium chloride, resistance mutants S-41, S-150, S-AB-23, S-AB-38, and S-AB-73 were selected and these mutants also showed a 2-64-fold stable minimum inhibitory concentration (MIC) increase to chloramphenicol, ciprofloxacin, nalidixic acid, and tetracycline. In S-41 and S-150, the expression of acrB was increased 2.7- and 7.6-fold, and ΔtolC or ΔacrAB mutants of S-41 and S-150 showed the same MICs to all tested antimicrobials as the equivalent Salmonella Typhimurium 14028s mutants. However, in S-AB-23, S-AB-38, and S-AB-73, the expression of acrF was increased 96-, 230-, and 267-fold, respectively, and ΔtolC or ΔacrEF mutants of S-AB-23, S-AB-38, and S-AB-73 showed the similar MICs to all tested antimicrobials as the ΔtolC mutant of Salmonella Typhimurium 14028s. Our data showed that constitutively over-expressed AcrAB working through TolC was the main resistance mechanism in ST14028s benzalkonium chloride resistance mutants. However, after AcrAB had been inactivated, benzalkonium chloride-resistant mutants could still be selected and constitutively over-expressed, AcrEF became the dominant efflux pump working through TolC and being responsible for the increasing antimicrobial resistance. These data indicated that different mechanisms existed for acrB and acrF constitutive over-expression. Since exposure to benzalkonium chloride may lead to Salmonella mutants with a decreased susceptibility to quinolones, which is currently one of the drugs of choice for the treatment of life-threatening salmonelosis, research into the pathogenesis and epidemiology of the benzalkonium chloride resistance mutants will be of increasing importance.

  18. Aspergilli Response to Benzalkonium Chloride and Novel-Synthesized Fullerenol/Benzalkonium Chloride Nanocomposite

    Directory of Open Access Journals (Sweden)

    Nikola Unković

    2015-01-01

    Full Text Available A comprehensive comparative analysis of antifungal potential of benzalkonium chloride and newly synthesized fullerenol/benzalkonium chloride nanocomposite was conducted to assess the possible impact of carbon-based nanocarrier on antimicrobial properties of the commonly used biocide. Physical characterization of synthesized nanocomposite showed zeta potential of +37.4 mV and inhomogeneous particles size distribution, with nanocomposite particles’ dimensions within 30–143 nm and maximum number of particles at 44 nm. The effect of pure and fullerenol nanocarrier-bound biocide was evaluated in eight Aspergillus species. In mycelial growth assay, nanocomposite was more potent, as fungicidal effect of 1.04/0.6 μg mL−1 was obtained in all but one of the isolates (A. niger, while proportional concentration of pure biocide (0.6 μg mL−1 completely inhibited mycelial growth of only three Aspergillus species. However, conidia appear to be less susceptible to nanocomposite treatment, as lower fungistatic (MIC and fungicidal (MFC concentrations were obtained with biocide alone (MIC in range from 0.03 to 0.15 μg mL−1 and MFC from 0.075 to 0.45 μg mL−1. To a different degree, both substances stimulated aflatoxin B1 production and inhibited ochratoxin A synthesis. Very low mycelium biomass yield, in range from 1.0 to 3.0 mg dry weight, was documented in both biocide and nanocomposite enriched medium.

  19. Benzalkonium Chloride Intoxication Mimicking Herpes Zoster Encephalitis

    Directory of Open Access Journals (Sweden)

    Ekrem Güler

    2011-06-01

    Full Text Available Benzalkonium chloride (BAC is a frequently used disinfectant and its most well-known side effect is contact dermatitis. In this report, two children who had vesicular dermatitis, headache, lethargy, fever and encephalopathy mimicking Herpes zoster encephalitis were presented. Their consciousness level improved on the second day. From the medical history it was understood that the mother had applied 20% BAC solution to the scalps of two children. The aim of the presentation of this report is to draw attention to the fact that BAC application to the scalp for treating pediculosis capitis may resemble the herpes encephalitis clinical picture.

  20. AGING OF ADHESIVE INTERFACES TREATED WITH BENZALKONIUM CHLORIDE AND BENZALKONIUM METHACRYLATE

    OpenAIRE

    Sabatini, Camila; Pashley, David H.

    2015-01-01

    Inhibition of endogenous dentin matrix metalloproteinases (MMPs) within incompletely infiltrated hybrid layers can contribute to the preservation of resin-dentin bonds. This study evaluated the bond stability of interfaces treated with benzalkonium chloride (BAC) and benzalkonium methacrylate (MBAC), and its inhibitory properties in dentin MMP activity. Single-component adhesive ALL-BOND UNIVERSAL, modified with BAC or MBAC in concentrations of 0, 0.5, 1.0 and 2.0% was used for microtensile b...

  1. Interactions of benzalkonium chloride with soft and hard contact lenses

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, J.M.; Cheeks, L.; Green, K. (Medical College of Georgia, Augusta (USA))

    1990-02-01

    We measured the uptake and washout of benzalkonium chloride, using radioactive tracer, by representative hard and soft contact lenses. Uptake by soft contact lenses after 7 days of continuous exposure is high (30 to 56 micrograms/mg of lens weight), with a low percentage of washout in 24 hours (between 0.2% and 1.5% of total uptake). High-water content lenses absorb greater quantities of benzalkonium than do low-water content lenses. Hard lenses take up a much smaller quantity of benzalkonium but release between 30% and 60% of total uptake during washout for 24 hours. Fluorosilicone-acrylate polymer lenses adsorb and release the most preservative, while polymethylmethacrylate lenses (Paragon Optical Inc, Mesa, Ariz) adsorb and release the least. The released benzalkonium from either soft or hard lenses is of a sufficient concentration to be at or above the upper limits of safety.

  2. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    Science.gov (United States)

    Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

    2012-01-01

    Purpose. The aim of this study was to determine and characterize the effect of topical application of benzalkonium chloride (BAK) on corneal nerves in vivo and in vitro. Methods. Thy1-YFP+ neurofluorescent mouse eyes were treated topically with vehicle or BAK (0.01% or 0.1%). Wide-field stereofluorescence microscopy was performed to sequentially image the treated corneas in vivo every week for 4 weeks, and changes in stromal nerve fiber density (NFD) and aqueous tear production were determined. Whole-mount immunofluorescence staining of corneas was performed with antibodies to axonopathy marker SMI-32. Western immunoblot analyses were performed on trigeminal ganglion and corneal lysates to determine abundance of proteins associated with neurotoxicity and regeneration. Compartmental culture of trigeminal ganglion neurons was performed in Campenot devices to determine whether BAK affects neurite outgrowth. Results. BAK-treated corneas exhibited significantly reduced NFD and aqueous tear production, and increased inflammatory cell infiltration and fluorescein staining at 1 week (P < 0.05). These changes were most significant after 0.1% BAK treatment. The extent of inflammatory cell infiltration in the cornea showed a significant negative correlation with NFD. Sequential in vivo imaging of corneas showed two forms of BAK-induced neurotoxicity: reversible neurotoxicity characterized by axonopathy and recovery, and irreversible neurotoxicity characterized by nerve degeneration and regeneration. Increased abundance of beta III tubulin in corneal lysates confirmed regeneration. A dose-related significant reduction in neurites occurred after BAK addition to compartmental cultures of dissociated trigeminal ganglion cells. Although both BAK doses (0.0001% and 0.001%) reduced nerve fiber length, the reduction was significantly more with the higher dose (P < 0.001). Conclusion. Topical application of BAK to the eye causes corneal neurotoxicity, inflammation, and reduced aqueous

  3. Controversy: Is Benzalkonium Chloride Necessary in Antiglaucoma Drops?

    Science.gov (United States)

    Louati, Y

    2012-01-01

    ABSTRACT Medical therapy is the first-line option in glaucoma management, with benzalkonium chloride (BAC) being the most frequently used preservative in antiglaucoma medications. Its use is however, known to be associated with deleterious effects on the ocular surface. This review is an attempt to critically evaluate whether BAC really is indispensable for better bioavailability of antiglaucoma drugs and consequently, better IOP control. How to cite this article: Louati Y, Shaarawy T. Controversy: Is Benzalkonium Chloride Necessary in Antiglaucoma Drops? J Current Glau Prac 2012;6(3):104-107. PMID:26997764

  4. Mechanism of resistance to benzalkonium chloride by Pseudomonas aeruginosa.

    Science.gov (United States)

    Sakagami, Y; Yokoyama, H; Nishimura, H; Ose, Y; Tashima, T

    1989-01-01

    The mechanisms of resistance of Pseudomonas aeruginosa to benzalkonium chloride (BC) were studied. The effluence of cell components was observed in susceptible P. aeruginosa by electron microscopy, but resistant P. aeruginosa seemed to be undamaged. No marked changes in cell surface potential between Escherichia coli NIHJC-2 and a spheroplast strain were found. The contents of phospholipids (PL) and fatty and neutral lipids (FNL) in the cell walls of resistant P. aeruginosa were higher than those in the cell walls of susceptible P. aeruginosa. The amounts of BC adsorbed to PL and FNL of cell walls of BC-resistant P. aeruginosa were lower than those for BC-susceptible P. aeruginosa. Fifteen species of cellular fatty acids were identified by capillary gas chromatography and gas chromatography-mass spectrometry. The ability of BC to permeate the cell wall was reduced because of the increase in cellular fatty acids. These results suggested that the resistance of P. aeruginosa to BC is mainly a result of increased in the contents of PL and FNL. In resistant P. aeruginosa, the decrease in the amount of BC adsorbed is likely to be the result of increases in the contents of PL and FNL. Images PMID:2506813

  5. Epidemic septic arthritis caused by Serratia marcescens and associated with a benzalkonium chloride antiseptic.

    Science.gov (United States)

    Nakashima, A K; McCarthy, M A; Martone, W J; Anderson, R L

    1987-01-01

    During a 6-week period, 10 patients were admitted to a hospital for treatment of knee or shoulder joint infections due to Serratia species. Isolates from eight patients were identified as Serratia marcescens with identical biochemical characteristics and antibiotic susceptibility patterns. Before the onset of infections, all patients had been treated by two orthopedic surgeons who shared an office. Studies revealed that infections were associated with previous joint injections (P = 4.44 X 10(-5] of methylprednisolone and lidocaine. Environmental cultures revealed that a canister of cotton balls soaked in aqueous benzalkonium chloride and two multiple-dose vials of methylprednisolone previously used by office personnel were contaminated with the epidemic strain of S. marcescens. The canister may have served as a potential reservoir for contamination of sterile solutions and equipment used for joint injections, of skin at the injection site, and of hands of personnel. No further cases occurred after the use of aqueous benzalkonium chloride was discontinued. PMID:3298308

  6. Inactivation of human immunodeficiency virus type 1 in tissue culture fluid and in genital secretions by the spermicide benzalkonium chloride.

    Science.gov (United States)

    Wainberg, M A; Spira, B; Bleau, G; Thomas, R

    1990-01-01

    We have shown that the spermicidal agent benzalkonium chloride can exert a direct inhibitory effect on the viral reverse transcriptase activity of human immunodeficiency virus type 1 (HIV-1) when utilized at concentrations of 0.05% and higher. Exposure of HIV-1 to this disinfectant at concentrations of more than 0.05% was able to completely destroy viral infectivity, as assessed on susceptible target cells. We have further shown that HIV-1, which is present in both seminal and genital secretions, can be inactivated in such fluids by direct exposure to benzalkonium chloride. PMID:1688873

  7. The contribution of histamine release to bronchoconstriction provoked by inhaled benzalkonium chloride in asthma.

    Science.gov (United States)

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

    1988-01-01

    1. To investigate the possibility that benzalkonium chloride-induced bronchoconstriction results from the endogenous release of histamine, we examined the effect of the selective histamine antagonists terfenadine and astemizole, on the airways response to inhaled benzalkonium chloride and histamine in 12 asthmatic subjects. 2. Double-blind concentration- and time-course studies were undertaken, 3 h after treatment with terfenadine or matched placebo. 3. Benzalkonium chloride and histamine caused concentration-related falls in FEV1 in all subjects with benzalkonium chloride being 7.4 times less potent as a bronchoconstrictor agonist than histamine. Terfenadine displaced to the right the benzalkonium chloride and histamine concentration-response curves by 3.7 and 111 fold respectively. Terfenadine attenuated the initial (5 min) bronchoconstrictor response to benzalkonium chloride by 40%. However, over the whole 45 min period, the response was reduced by only 13% compared with 86% inhibition of the response to histamine. 4. In an open study, eight of the 12 subjects undertook a time course study with inhaled benzalkonium chloride after pretreatment with the chemically unrelated histamine antagonist astemizole. Astemizole inhibited benzalkonium chloride-induced bronchoconstriction to an almost identical degree as that achieved with terfenadine. 5. We conclude that the initial bronchoconstrictor effect of benzalkonium chloride is due, in part, to histamine release. However, the majority of the adverse effect relates to other, as yet unrecognised effects of this bacteriocidal substance. PMID:2451929

  8. Anaphylactic reaction following administration of nose drops containing benzalkonium chloride

    Directory of Open Access Journals (Sweden)

    Mezger Elke

    2012-10-01

    Full Text Available Abstract We describe a case of anaphylactic reaction in a 46-year-old female post application of decongestant nose drops containing benzalkonium chloride (BAC. With some latency, the patient complained of cough, dyspnea, sensation of heat, croakiness and pruritus. Since she showed all of these symptoms, typical of an anaphylactic reaction, we proceeded some weeks later with a prick test with solutions containing BAC, a cationic surfactant commonly used as an antibacterial preservative in many medical solutions. The prick test was positive, confirming the assumption of a hypersensitive reaction to BAC.

  9. Anaphylactic reaction following administration of nose drops containing benzalkonium chloride

    Science.gov (United States)

    2012-01-01

    We describe a case of anaphylactic reaction in a 46-year-old female post application of decongestant nose drops containing benzalkonium chloride (BAC). With some latency, the patient complained of cough, dyspnea, sensation of heat, croakiness and pruritus. Since she showed all of these symptoms, typical of an anaphylactic reaction, we proceeded some weeks later with a prick test with solutions containing BAC, a cationic surfactant commonly used as an antibacterial preservative in many medical solutions. The prick test was positive, confirming the assumption of a hypersensitive reaction to BAC. PMID:23078861

  10. EVALUATION OF FUNGICIDAL EFFICIENEY OF IRANIAN MADE BENZALKONIUM CHLORIDE

    Directory of Open Access Journals (Sweden)

    K. Imandel

    1995-12-01

    Full Text Available Fungicidal efficiency of Iranian made benzalkonium chloride named Akhgar, Afshang and Hamoon were evaluated on pure culture species of Aspergillus nijer, Candida ablicans and Mucour according to the standard method No. 2442 issued by the Institute of Standards and Industrial Research of Iran, from October 1993 to March 1994. Suspensions were prepared in a way that each cubic centimeter having 3.5×107 condia of Aspergillus nijer, 4×107 Candida albicans yeast cell and 2×107 Mucour spore, and Improved Neubauer slide counting cell were used for enumeration. These laboratory study showed that Lecithine and Tween were the best neutralizers with equal power. Usage of five dilutions of 0.4, 0.6, 0.8, 1 fungus separately at 6.5 to 6.7 pH, confirmed the correctness of dilution figure of 0.4 percent proposed by producer companies and showed that these fungi are still sensitive against Benzalkonium Chloride disinfectants.

  11. Aging of adhesive interfaces treated with benzalkonium chloride and benzalkonium methacrylate.

    Science.gov (United States)

    Sabatini, Camila; Pashley, David H

    2015-04-01

    Inhibition of endogenous dentin matrix metalloproteinases (MMPs) within incompletely infiltrated hybrid layers can contribute to the preservation of resin-dentin bonds. This study evaluated the bond stability of interfaces treated with benzalkonium chloride (BAC) and benzalkonium methacrylate (MBAC), and the inhibitory properties of these compounds on dentin MMP activity. Single-component adhesive ALL-BOND UNIVERSAL, modified with BAC or MBAC at concentrations of 0, 0.5, 1.0, and 2.0%, was used for microtensile bond strength (μTBS) evaluation after 24 h, 6 months, and 1 yr. Beams produced from human dentin were treated with 37% phosphoric acid, dipped in 0.5% BAC, 1.0% BAC, or water (control) for 60 s, and then incubated in SensoLyte generic MMP substrate to determine MMP activity. A significant decrease in the μTBS after 6 months and 1 yr was observed for the control group only. No significant differences among groups were shown at 24 h. After 6 months and 1 yr, the control group demonstrated significantly lower μTBS than all treatment groups. When applied for 60 s, 0.5% BAC inhibited total MMP activity by 31%, and 1.0% BAC inhibited total MMP activity by 54%. Both BAC and MBAC contributed to the preservation of resin-dentin bonds, probably because of their inhibitory properties of endogenous dentin proteinases.

  12. [Toxicity research status of benzalkonium chloride on ocular surface].

    Science.gov (United States)

    Huang, Caihong; Chen, Wensheng; Chen, Yongxiong; Liu, Zuguo

    2014-04-01

    Benzalkonium chloride (BAC) is the most commonly used preservative in ophthalmic preparations.So far large bodies of clinical and experimental studies have shown that use of topical drugs containing BAC can induce a series of ocular surface diseases, such as apoptosis.However, recently, some clinical studies have shown that ocular toxicity in patients treated with eye drops containing BAC has not apparent correlated with BAC.Some scholars consider that the limitations of the research lead people to recognize the BAC toxicity exaggeratedly.Here we summarize numerous clinical and experimental studies of BAC in the past few years, and focus on reviewing recent researches of the toxic effect of BAC on ocular surface.

  13. Matrix metalloproteinase inhibitory properties of benzalkonium chloride stabilizes adhesive interfaces.

    Science.gov (United States)

    Sabatini, Camila; Patel, Shaival K

    2013-12-01

    This study evaluated the effects of different concentrations of benzalkonium chloride (BAC) on the preservation of adhesive interfaces created with two etch-and-rinse adhesives and its inhibitory properties on dentin matrix metalloproteinase (MMP) activity. The following groups were tested with the adhesive systems Optibond Solo Plus and All-Bond 3: Group 1, adhesive without inhibitor (control); Group 2, topical 2.0% chlorhexidine (2.0% CHX); Group 3, phosphoric acid with 1.0%wt BAC (BAC-PA); Group 4, 0.25% BAC-adhesive (0.25% BAC); Group 5, 0.5% BAC-adhesive (0.5% BAC); Group 6, 1.0% BAC-adhesive (1.0% BAC); and Group 7, 2.0% BAC-adhesive (2.0% BAC). Composite cylinders were fabricated, and shear bond strength (SBS) was evaluated after 24 h, 6 months, and 18 months of storage. Extracts from concentrated demineralized human dentin powder were subjected to SDS-PAGE and incubated in the presence of 0.25, 0.5, 1.0, and 2.0% BAC. Overall, stable bonds were maintained for 18 months. Improved bond strengths were seen for 0.5% BAC and 1.0% BAC when bonding with Optibond Solo Plus, and for 0.25% BAC and 0.5% BAC when bonding with All-Bond 3. Zymographic analysis revealed complete inhibition of gelatinolytic activity with BAC. Benzalkonium chloride, at all concentrations, inhibited dentin proteolytic activity, which seems to have contributed to the improved bond stability after 18 months for specific combinations of BAC concentration and adhesive.

  14. Granular parakeratosis induced by benzalkonium chloride exposure from laundry rinse aids.

    Science.gov (United States)

    Robinson, Aaron J; Foster, Rachael S; Halbert, Anne R; King, Emma; Orchard, David

    2016-09-19

    Benzalkonium chloride is a quaternary ammonium cationic detergent present in a number of household products, which can act as a major skin irritant. We present the case of six children who developed granular parakeratosis after exposure to benzalkonium chloride in laundry rinse aids, presenting as a brightly erythematous, tender but minimally pruritic, intertriginous eruption followed by superficial desquamation. The eruptions resolved over 3-4 weeks after cessation of exposure.

  15. Nosocomial transmission of Serratia marcescens in a veterinary hospital due to contamination by benzalkonium chloride.

    Science.gov (United States)

    Fox, J G; Beaucage, C M; Folta, C A; Thornton, G W

    1981-01-01

    During a 1-year period, Serratia marcescens was isolated from 50% of all contaminate intravenous catheters from dogs and cats in a large veterinary hospital. S. marcescens was also isolated from respiratory tracts, genitourinary tracts, skin, and other sites in hospitalized animals. A total of 55% of the clinical isolates and 66% of the intravenous catheter isolates had the same API biochemical profile. The source of the S. marcescens was determined to be aqueous benzalkonium chloride (0.025%) sponge pots located in the intensive care unit, surgery rooms, and outpatient clinic areas of the hospital. Of the 11 S. marcescens isolates submitted to the Centers for Disease Control for serotyping (6 from aqueous benzalkonium chloride sponge pots, 5 from intravenous catheters), 8 were identified as serotype O10:H11. All S. marcescens isolates tested for antibiotic susceptibilities were multiply resistant; isolates were most frequently resistant to streptomycin, cephalothin, and ampicillin. This study demonstrates that improper use of disinfectants plays an important role in the nosocomial transmission of S. marcescens. PMID:7024303

  16. Zinc-related actions of sublethal levels of benzalkonium chloride: Potentiation of benzalkonium cytotoxicity by zinc.

    Science.gov (United States)

    Mitani, Tsuyoshi; Elmarhomy, Ahmed Ibrahim Elhossany; Dulamjav, Luvsandorj; Anu, Enkhtumur; Saitoh, Shohei; Ishida, Shiro; Oyama, Yasuo

    2017-04-25

    Benzalkonium chloride (BZK) is a common preservative used in pharmaceutical and personal care products. ZnCl2 was recently reported to significantly potentiate the cytotoxicity of some biocidal compounds. In the present study, therefore, we compared the cytotoxic potency of BZK and then further studied the Zn(2+)-related actions of the most cytotoxic agent among BZK, using flow cytometric techniques with appropriate fluorescent probes in rat thymocytes. Cytotoxicity of benzylcetyldimethylammonium (BZK-C16) was more potent that those of benzyldodecyldimethylammonium and benzyldimethyltetradecylammonium. ZnCl2 (1-10 μM) significantly potentiated the cytotoxicity of BZK-C16 at a sublethal concentration (1 μM). The co-treatment of cells with 3 μM ZnCl2 and 1 μM BZK-C16 increased the population of both living cells with phosphatidylserine exposed on membrane surfaces and dead cells. BZK-C16 at 0.3-1.0 μM elevated intracellular Zn(2+) levels by increasing Zn(2+) influx, and augmented the cytotoxicity of 100 μM H2O2. Zn(2+) is concluded to facilitate the toxicity of BZK. We suggest that the toxicity of BZK is determined after taking extracellular (plasma) and/or environmental Zn(2+) levels into account.

  17. Benzalkonium Chloride Induced Bronchoconstriction in Patients with Stable Bronchial Asthma

    Science.gov (United States)

    Lee, Byoung Hoon

    2007-01-01

    Background Although benzalkonium chloride (BAC)-induced bronchoconstriction occurs in patients with bronchial asthma, BAC-containing nebulizer solutions are still being used in daily practice in Korea. The aim of this study was to evaluate the effects of inhaled aqueous solutions containing BAC. Methods Thirty subjects with bronchial asthma and 10 normal controls inhaled up to three 600 µg nebulized doses of BAC using a jet nebulizer. FEV1 (forced expiratory volume at one second) was measured 15 minutes after each dose. Inhalations were repeated every 20 minutes until FEV1 decreased by 15% or more (defined as BAC-induced bronchoconstriction) or the 3 doses were administered. Results The percent fall in FEV1 in response to BAC inhalation was significantly higher in asthmatics than in normal subjects (p<0.05). BAC administration in subjects with asthma reached a plateau (maximal effect). BAC-induced bronchoconstriction was found in 6 asthmatics (20%), with two responders after the 2nd inhalation and after the 3rd inhalation. The percent fall in FEV1 in response to the 1st inhalation of BAC was significantly higher in asthmatics with higher bronchial hyperresponsiveness (BHR) than in those with lower BHR. Conclusions This study suggests that the available multi-dose nebulized solution is generally safe. However, significant bronchoconstriction can occur at a relatively low BAC dose in asthmatics with severe airway responsiveness. PMID:18309682

  18. Ocular toxicity of benzalkonium chloride homologs compared with their mixtures.

    Science.gov (United States)

    Okahara, Akihiko; Tanioka, Hidetoshi; Takada, Koichi; Kawazu, Kouichi

    2013-12-01

    This study was performed to assess the in vivo ocular toxicity of benzalkonium chloride (BAK) homologs compared with commercially available BAK (BAK mixture) and to assess the ocular toxicity of BAK homolog after repeated ocular application. Rabbit eyes were examined by ophthalmology and scanning electron microscopy (SEM) after 10 applications of BAK homologs with C12 (C12-BAK) and C14 (C14-BAK) alkyl chain lengths and a BAK mixture at concentrations of 0.001% (w/v), 0.003% (w/v), 0.005% (w/v), 0.01% (w/v) and 0.03% (w/v). The ocular toxicity of C12-BAK to rabbit eyes was examined by ophthalmology and histopathology after repeated ocular application for 39 weeks. In addition, the antimicrobial activities of C12-BAK and C14-BAK against A. niger, S. aureus and P. aeruginosa were assessed. Ocular toxicity of C12-BAK was less than those of the BAK mixture and C14-BAK. No ocular toxicity was noted after ocular application of 0.01% C12-BAK to rabbits for 39 weeks. C12-BAK showed antimicrobial activities at a concentration of 0.003%. These results suggest that the use of C12-BAK to replace BAK mixture as a preservative in ophthalmic solutions should be considered in order to reduce the incidence of the corneal epithelial cell injury induced clinically by BAK.

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

    Science.gov (United States)

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

    1988-01-01

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

  20. Assessment of the efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and Tetrahymena spp.

    Science.gov (United States)

    Vaerewijck, M J M; Sabbe, K; Baré, J; Spengler, H-P; Favoreel, H W; Houf, K

    2012-03-01

    The efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and two Tetrahymena spp. was determined based on the European Standard EN 1276:2009 suspension test. Trophozoite viability was assessed by determination of the membrane integrity using flow cytometry as a fast screening technique. Bovine serum albumin was added to simulate clean (0.3 g/liter) and dirty (3 g/liter) conditions. Benzalkonium chloride caused cell lysis at concentrations above 50 mg/liter under clean and dirty conditions. A concentration of 50 mg of free chlorine per liter had a strong biocidal effect on acanthamoebae and tetrahymenae after 15 min under clean and dirty conditions. Our results suggest that benzalkonium chloride and sodium hypochlorite were effective against the three microorganisms at concentrations commonly applied in the food industry.

  1. Benzalkonium chloride suppresses rabbit corneal endothelium intercellular gap junction communication.

    Directory of Open Access Journals (Sweden)

    Zhenhao Zhang

    Full Text Available Gap junction intercellular communication (GJIC plays a critical role in the maintenance of corneal endothelium homeostasis. We determined if benzalkonium chloride (BAK alters GJIC activity in the rabbit corneal endothelium since it is commonly used as a drug preservative in ocular eyedrop preparations even though it can have cytotoxic effects.Thirty-six adult New Zealand albino rabbits were randomly divided into three groups. BAK at 0.01%, 0.05%, and 0.1% was applied twice daily to one eye of each of the rabbits in one of the three groups for seven days. The contralateral untreated eyes were used as controls. Corneal endothelial morphological features were observed by in vivo confocal microscopy (IVCM. Immunofluorescent staining resolved changes in gap junction integrity and localization. Western blot analysis and RT-PCR evaluated changes in levels of connexin43 (Cx43 and tight junction zonula occludens-1 (ZO-1 gene and protein expression, respectively. Cx43 and ZO-1 physical interaction was detected by immunoprecipitation (IP. Primary rabbit corneal endothelial cells were cultured in Dulbecco's Modified Eagle Medium (DMEM containing BAK for 24 hours. The scrape-loading dye transfer technique (SLDT was used to assess GJIC activity.Topical administration of BAK (0.05%, 0.1% dose dependently disrupted corneal endothelial cell morphology, altered Cx43 and ZO-1 distribution and reduced Cx43 expression. BAK also markedly induced increases in Cx43 phosphorylation status concomitant with decreases in the Cx43-ZO-1 protein-protein interaction. These changes were associated with marked declines in GJIC activity.The dose dependent declines in rabbit corneal endothelial GJIC activity induced by BAK are associated with less Cx43-ZO-1 interaction possibly arising from increases in Cx43 phosphorylation and declines in its protein expression. These novel changes provide additional evidence that BAK containing eyedrop preparations should be used with caution to

  2. The anti-MMP activity of benzalkonium chloride

    Science.gov (United States)

    Tezvergil-Mutluay, Arzu; Mutluay, M. Murat; Gu, Li-sha; Zhang, Kai; Agee, Kelli A.; Carvalho, Ricardo M.; Manso, Adriana; Carrilho, Marcela; Tay, Franklin R.; Breschi, Lorenzo; Suh, Byoung-In; Pashley, David H.

    2013-01-01

    SUMMARY Objective This study evaluated the ability of benzalkonium chloride (BAC) to bind to dentine and to inhibit soluble recombinant MMPs and bound dentine matrix metalloproteinases (MMPs). Methods Dentine powder was prepared from extracted human molars. Half was left mineralized; the other half was completely demineralized. The binding of BAC to dentine powder was followed by measuring changes in the supernatant concentration using UV spectrometry. The inhibitory effects of BAC on rhMMP-2, -8 and -9 were followed using a commercially available in vitro proteolytic assay. Matrix-bound endogenous MMP-activity was evaluated in completely demineralized beams. Each beam was either dipped into BAC and then dropped into 1 mL of a complete medium (CM) or they were placed in 1 mL of CM containing BAC for 30 d. After 30 d, changes in the dry mass of the beams or in the hydroxyproline (HYP) content of hydrolyzates of the media were quantitated as indirect measures of matrix collagen hydrolysis by MMPs. Results Demineralized dentine powder took up 10-times more BAC than did mineralized powder. Water rinsing removed about 50% of the bound BAC, while rinsing with 0.5 M NaCl removed more than 90% of the bound BAC. BAC concentrations 0.5 wt% produced 100% inhibition of soluble recombinant MMP-2, -8 or -9, and inhibited matrix-bound MMPs between 55-66% when measured as mass loss or 76-81% when measured as solubilization of collagen peptide fragments. Conclusions BAC is effective at inhibiting both soluble recombinant MMPs and matrix-bound dentine MMPs in the absence of resins. PMID:20951183

  3. Sodium perbarate and benzalkonium chloride induce DNA damage in Chang conjunctival epithelial cells.

    Science.gov (United States)

    Zhang, Huina; Wu, Han; Yang, Jun; Ye, Juan

    2017-02-06

    Content and objective: To investigate and compare the toxic effects of benzalkonium chloride (BAC) and new type oxidative preservative sodium perborate (NaBO3) on DNA damage, reactive oxygen species (ROS), and cell survival in immortalized human Chang conjunctival cells.

  4. Gene expression in Listeria monocytogenes exposed to sublethal concentration of benzalkonium chloride.

    Science.gov (United States)

    Tamburro, Manuela; Ripabelli, Giancarlo; Vitullo, Monia; Dallman, Timothy James; Pontello, Mirella; Amar, Corinne Francoise Laurence; Sammarco, Michela Lucia

    2015-06-01

    In this study, tolerance at sublethal concentration of benzalkonium chloride and transcription levels of mdrL, ladR, lde, sigB and bcrABC genes in Listeria monocytogenes strains were evaluated. Viable cells reduction occurred in 45% of strains and clinical isolates showed lower sensitivity than isolates from foods. An increased transcription of an efflux system encoding gene was found in 60% of strains, and simultaneous mdrL overexpression and ladR underexpression occurred in 30% of isolates. A significant association between reduced benzalkonium chloride activity and both mdrL and sigB overexpression was observed; sigB expression also correlated with both mdrL and ladR genes. The bcrABC gene was only found in six strains, all isolated from foods and sensitive to benzalkonium chloride, and in four strains an underexpression was observed. Disinfection at sublethal concentration was less effective in clinical isolates, and mdrL and sigB expression was significantly affected by disinfection. Further insights are needed to understand the adaptation to benzalkonium chloride and to evaluate whether changes in gene expression could affect the L. monocytogenes virulence traits and persistence in the environment.

  5. Effect of benzalkonium chloride on the stability of the precorneal tear film in rabbit and man.

    Science.gov (United States)

    Wilson, W. S.; Duncan, A. J.; Jay, J. L.

    1975-01-01

    Benzalkonium chloride, a surface-active preservative commonly used in eyedrop preparations, has been shown to hasten the drying of the precorneal tear film. In the rabbit, 0.01 per cent benzalkonium (the concentration usually employed as a preservative) shortened the time required for the appearance of dry spots on the corneal surface by a factor of about four. In man, an approximately twofold hastening was demonstrated. This effect is thought to preclude the use of this substance as a preservative in eyedrop preparations for use as local anaesthetics. PMID:1203224

  6. Conservation and distribution of the benzalkonium chloride resistance cassette bcrABC in Listeria monocytogenes.

    Science.gov (United States)

    Dutta, Vikrant; Elhanafi, Driss; Kathariou, Sophia

    2013-10-01

    Analysis of a panel of 116 Listeria monocytogenes strains of diverse serotypes and sources (clinical, environment of food processing plants, and food) revealed that all but one of the 71 benzalkonium chloride-resistant (BC(r)) isolates harbored bcrABC, previously identified on a large plasmid (pLM80) of the 1998-1999 hot dog outbreak strain H7858. In contrast, bcrABC was not detected among BC-susceptible (BC(s)) isolates. The bcrABC sequences were highly conserved among strains of different serotypes, but variability was noted in sequences flanking bcrABC. The majority of the BC(r) isolates had either the pLM80-type of organization of the bcrABC region or appeared to harbor bcrABC on the chromosome, adjacent to novel sequences. Transcription of bcrABC was induced by BC (10 μg/ml) in strains of different serotypes and diverse bcrABC region organization. These findings reveal widespread dissemination of bcrABC across BC(r) L. monocytogenes strains regardless of serotype and source, while also suggesting possible mechanisms of bcrABC dissemination across L. monocytogenes genomes.

  7. Evaluation of antibiofilm effect of benzalkonium chloride, iodophore and sodium hypochlorite against biofilm of Pseudomonas aeruginosa of dairy origin.

    Science.gov (United States)

    Pagedar, Ankita; Singh, Jitender

    2015-08-01

    The present study was undertaken with objectives of; a) to investigate and compare Pseudomonas aeruginosa isolates from two dairies for biofilm formation potential and, b) to compares three common biocides for biofilm eradication efficiencies. Amongst the isolates from commercial dairy, 70 % were strong and/or moderate biofilm former in comparison to 40 % isolates from small scale dairy. All isolates, irrespective of source, exhibited higher susceptibility to biocides in planktonic stage than in biofilm. Antibiofilm efficiencies of three biocides i.e. benzalkonium chloride, sodium hypochlorite and iodophore were determined in terms of their microbial biofilms eradicating concentration (MBEC). Our findings show that the three biocides were ineffective against preformed biofilms at recommended in-use concentrations. Biofilms were the most resistant to benzalkonium chloride and least against iodophore. A trend of decreasing MBECs was observed with extended contact time. The findings of present study warrant for a systematic approach for selecting types and concentrations of biocide for application as antibiofilm agent in food industry.

  8. Comparative biocidal activity of peracetic acid, benzalkonium chloride and ortho-phthalaldehyde on 77 bacterial strains.

    Science.gov (United States)

    Bridier, A; Briandet, R; Thomas, V; Dubois-Brissonnet, F

    2011-07-01

    Despite numerous reports on biocide activities, it is often difficult to have a reliable and relevant overview of bacterial resistance to disinfectants because each work challenges a limited number of strains and tested methods are often different. The aim of this study was to evaluate the bactericidal activity of three different disinfectants commonly used in industrial or medical environments (peracetic acid, benzalkonium chloride and ortho-phthalaldehyde) against 77 bacterial strains from different origins using one standard test method (NF EN 1040). Results highlight the existence of high interspecific variability of resistance to disinfectants and, contrary to widespread belief, Gram-positive strains generally appeared more resistant than Gram-negative strains. Resistance was also variable among strains of the same species such as Bacillus subtilis to peracetic acid, Pseudomonas aeruginosa to benzalkonium chloride and Staphylococcus aureus to ortho-phthalaldehyde.

  9. Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride

    OpenAIRE

    Youngbeom Ahn; Jeong Myeong Kim; Ohgew Kweon; Seong-Jae Kim; Jones, Richard C.; Kellie Woodling; Goncalo Gamboa da Costa; LiPuma, John J.; David Hussong; Marasa, Bernard S.; Cerniglia, Carl E.

    2016-01-01

    ABSTRACT Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethyl...

  10. Fourteen-year survival of Pseudomonas cepacia in a salts solution preserved with benzalkonium chloride.

    Science.gov (United States)

    Geftic, S G; Heymann, H; Adair, F W

    1979-01-01

    A strain of Pseudomonas cepacia that survived for 14 years (1963 to 1977) as a contaminant in an inorganic salt solution which contained commercial 0.05% benzalkonium chloride (CBC) as an antimicrobial preservative, was compared to a recent clinical isolate of P. cepacia. Ammonium acetate was present in the concentrated stock CBC solution, and served as a carbon and nitrogen source for growth when carried over into the salts solution with the CBC. The isolate's resistance to pure benzalkonium chloride was increased step-wise to a concentration of 16%. Plate counts showed 4 x 10(3) colony-forming units per ml in the salts solution. Comparison of growth rates, mouse virulence, antibiotics resistance spectra, and substrate requirements disclosed no differences between the contaminant and a recently isolated clinical strain of P. cepacia. The results indicate that it is critical that pharmaceutical solutions containing benzalkonium chloride as an antimicrobial preservative be formulated without extraneous carbon and nitrogen sources or be preserved with additional antimicrobial agents. PMID:453827

  11. Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride.

    Science.gov (United States)

    Ahn, Youngbeom; Kim, Jeong Myeong; Kweon, Ohgew; Kim, Seong-Jae; Jones, Richard C; Woodling, Kellie; Gamboa da Costa, Gonçalo; LiPuma, John J; Hussong, David; Marasa, Bernard S; Cerniglia, Carl E

    2016-11-22

    Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethylbenzylammonium chloride (C10BDMA-Cl), hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB) to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread.

  12. Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride

    Directory of Open Access Journals (Sweden)

    Youngbeom Ahn

    2016-11-01

    Full Text Available Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl, dodecyldimethylbenzylammonium chloride (C12BDMA-Cl, decyldimethylbenzylammonium chloride (C10BDMA-Cl, hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread.

  13. A hybridization approach to efficient TiO{sub 2} photodegradation of aqueous benzalkonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Suchithra, Padmajan Sasikala, E-mail: schithraps@gmail.com [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium); Carleer, Robert [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium); Ananthakumar, Solaippan [Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019 (India); Yperman, Jan, E-mail: jan.yperman@uhasselt.be [Research group of Applied and Analytical Chemistry, University Hasselt, Agoralaan, Gebouw D, BE-3590 Diepenbeek (Belgium)

    2015-08-15

    Graphical abstract: Hybridization of AC onto TiO{sub 2} tends the catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic surfactants. The photodegradation of benzalkonium chloride (BKC) is investigated. - Highlights: • Activated carbon-TiO{sub 2} composite (ACT) surface tends negative upon UV irradiation. • ACT effectively photodegrade cationic surfactant benzalkonium chloride (BKC). • Optimum pH for UV-photodegradation of BKC is 8 to 9 and reaction time is 2 h. • Aromatic moiety of BKC is degraded faster than long alkyl chain. • UV–vis spectroscopy is sensitive to detect aqueous BKC from 1 μg/mL. - Abstract: TiO{sub 2} get positively charged upon UV-irradiation and repel the cationic pollutants away from the surface. Hybridization of AC onto TiO{sub 2} (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 1 h UV-irradiation, but complete mineralization of BKC is achieved with 2 h UV-irradiation. We propose that BKC photodegradation starts by central fission of benzyl C−N bond followed by dealkylation, and demethylation steps.

  14. Comparative Phenotypic and Genotypic Analysis of Swiss and Finnish Listeria monocytogenes Isolates with Respect to Benzalkonium Chloride Resistance.

    Science.gov (United States)

    Meier, Anja B; Guldimann, Claudia; Markkula, Annukka; Pöntinen, Anna; Korkeala, Hannu; Tasara, Taurai

    2017-01-01

    Reduced susceptibility of Listeria monocytogenes to benzalkonium chloride (BC), a quaternary ammonium compound widely used in food processing and hospital environments, is a growing public health and food safety concern. The minimal inhibitory concentration of BC on 392 L. monocytogenes strains from Switzerland (CH) and Finland (FIN) was determined. Within this strain collection, benzalkonium chloride resistance was observed in 12.3% (24/195) of Swiss and 10.6% (21/197) of Finnish strains. In both countries, the highest prevalence of BC-resistant strains (CH: 29.4%; FIN: 38.9%) was detected among serotype 1/2c strains. Based on PCR analysis, genes coding for the qacH efflux pump system were detected for most of the BC-resistant strains (CH: 62.5%; FIN: 52.4%). Some Swiss BC-resistant strains harbored genes coding for the bcrABC (16.7%) efflux pump system, while one Finnish BC-resistant strain harbored the emrE gene previously only described among BC-resistant L. monocytogenes strains from Canada. Interestingly, a subset of BC-resistant strains (CH: 5/24, 20.8%; FIN: 9/21, 42.8%) lacked genes for efflux pumps currently known to confer BC resistance in L. monocytogenes. BC resistance analysis in presence of reserpine showed that the resistance was completely or partially efflux pump dependent in 10 out of the 14 strains lacking the known BC resistance genes. Sequence types 155 and ST403 were over-representated among these strains suggesting that these strains might share similar but yet unknown mechanisms of BC resistance.

  15. Survival of Serratia marcescens in benzalkonium chloride and in multiple-dose medication vials: relationship to epidemic septic arthritis.

    Science.gov (United States)

    Nakashima, A K; Highsmith, A K; Martone, W J

    1987-01-01

    In an epidemic of septic arthritis due to Serratia marcescens, the intra-articular injection of contaminated methylprednisolone may have played a key role. The epidemic strain was found in used multiple-dose vials of methylprednisolone and in a canister of cotton balls soaked in benzalkonium chloride. The cotton balls had been used for antisepsis and disinfection. Growth characteristics of the epidemic strain of S. marcescens were compared with those of control strains of S. marcescens which had been obtained from unrelated nosocomial outbreaks. The epidemic strain was able to survive in 1:100 dilutions of benzalkonium chloride and was able to grow to greater than 10(5) CFU/ml in multiple-dose vials of methylprednisoline; control strains could not be recovered after 24 h in the same solutions. The preservative in methylprednisolone is gamma-myristyl picolinium chloride, a compound chemically related to benzalkonium chloride. We speculate that the epidemic strain of S. marcescens, which was resistant to benzalkonium chloride, had cross-resistance to gamma-myristyl picolinium chloride. If the cotton balls were used to disinfect the tops of the multiple-dose vials of methylprednisolone, small numbers of organisms subsequently introduced into the solution could have grown to high concentrations. PMID:3298309

  16. Benzalkonium chloride and heavy-metal tolerance in Listeria monocytogenes from retail foods.

    Science.gov (United States)

    Xu, Dongyang; Li, Yanli; Zahid, M Shamim Hasan; Yamasaki, Shinji; Shi, Lei; Li, Jian-rong; Yan, He

    2014-11-03

    Phenotypic and genotypic tolerance in 71 Listeria monocytogenes isolates from different varieties of foods to benzalkonium chloride (BC) and cadmium were investigated by susceptibility test and molecular methods. To investigate the role of efflux pumps in BC tolerance, reserpine, an efflux pump inhibitor, was added to the BC tolerant strains. Tolerance to BC and cadmium were 26.8% (19/71) and 49.3% (35/71) respectively. Strains with BC tolerance were significantly more frequent among those of serotype 4b (100%, 6/6) than among those of serotype 1/2a (or 3a) (13.5%, 5/37), which represent the predominant number of strains (52.1%, 37/71). Tolerance to cadmium was encountered among 62.2% (23/37) and 50.0% (3/6) of the serotype 1/2a (or 3a) and 4b strains, respectively, and among 19.0% (4/21) of the strains of the serotype 1/2c. All of the 10 (14.1%) isolates found to be BC and cadmium co-tolerance were isolated from raw meat or quick-frozen food made of wheat flour and rice. Five multi-drug resistant strains were tolerant to cadmium as well. Among 71 isolates examined, one contained qacA and three contained qacEΔ1-sul. To the best of our knowledge, this is the first detection of qacA and qacEΔ1-sul in L. monocytogenes, an indication of the possible horizontal transfer of the two genes. Addition of reserpine to the tolerant strains resulted in the loss of tolerance among seven out of 19 BC strains, suggesting a certain role the efflux pump played in mediating BC tolerance. Of the three distinct cadA types known to date in L. monocytogenes, the cadA1 and cadA2 genes were detected among 24 (33.8%) and three (4.2%) isolates respectively. The presence of cadA1 and cadA2 largely corresponded to the susceptibility phenotype. A subset (9/35 [25.7%]) of the cadmium-tolerant isolates lacked the known cadmium resistance determinants. These findings suggest that food products could act as a reservoir for L. monocytogenes harboring tolerance to BC and cadmium and will further

  17. Resistance of Pseudomonas to Quaternary Ammonium Compounds. I. Growth in Benzalkonium Chloride Solution

    Science.gov (United States)

    Adair, Frank W.; Geftic, Sam G.; Gelzer, Justus

    1969-01-01

    Resistant cells of Pseudomonas aeruginosa and a waterborne Pseudomonas sp. (strain Z-R) were able to multiply in nitrogen-free minimal salts solution containing various concentrations of commercially prepared, ammonium acetate-buffered benzalkonium chloride (CBC), a potent antimicrobial agent. As the CBC concentration increased, growth increased until a point was reached at which the extent of growth leveled off or was completely depressed. Minimal salts solutions of pure benzalkonium chloride (PBC) containing no ammonium acetate did not support bacterial growth. When ammonium acetate was added to PBC solutions in the same concentrations found in CBC solutions, growth patterns developed that were comparable to those found with CBC. Likewise, (NH4)2SO4 added to PBC solutions supported growth of both organisms. P. aeruginosa was initially resistant to CBC levels of 0.02% and it was adapted to tolerate levels as high as 0.36%. Strain Z-R was naturally resistant to 0.4% CBC. Since ammonium acetate, carried over by the CBC used in drug formulations and disinfectant solutions, has the potential to support the growth of resistant bacteria and thus make possible the risk of serious infection, it is suggested that regulations allowing the presence of ammonium acetate in CBC solution be reconsidered. PMID:4984761

  18. Cluster of postinjection abscesses related to corticosteroid injections and use of benzalkonium chloride.

    Science.gov (United States)

    Olson, R K; Voorhees, R E; Eitzen, H E; Rolka, H; Sewell, C M

    1999-01-01

    Benzalkonium chloride (BC) is an unreliable disinfectant. A matched case-control study and environmental investigation were conducted to determine the cause of and risk factors for a cluster of postinjection abscesses at a private medical clinic where BC was used as a disinfectant. Twenty-eight case-patients who had an abscess at the injection site were matched with 126 control patients who had received an intramuscular injection at the clinic on the same day. Risk factors for abscess development in a multivariable logistic model were corticosteroid injection and being female. All case-patients had received a corticosteroid injection from a multidose vial. Cultures of abscesses from 20 of 23 case-patients grew Pseudomonas aeruginosa. Cultures of BC prepared at the clinic also grew P aeruginosa, suggesting that BC was the source of infection. Injection site cleaning with BC did not appear to be the route of infection since use of BC at the time of injection was not associated with abscess development. A more likely route of infection was injection of contaminated corticosteroid from multidose vials that could have been inoculated with pseudomonads via needle puncture after vial septa were wiped with contaminated BC. Benzalkonium chloride should not be used to clean injection vial septa or injection sites. PMID:10214100

  19. Cytotoxicity of prostaglandin analog eye drops preserved with benzalkonium chloride in multiple corneoconjunctival cell lines

    Science.gov (United States)

    Ayaki, Masahiko; Iwasawa, Atsuo

    2010-01-01

    Purpose: This study evaluated the cytotoxicity of five prostaglandin analog ophthalmic solutions on four ocular surface cell lines, ie, Chang (human conjunctiva), SIRC (rabbit cornea), RC-1 (rabbit cornea), and BCE C/D-1b (bovine cornea). Methods: Cell viability was measured by neutral red and MTT assays in cells treated for 10, 30, or 60 minutes with various doses of prostaglandins (undiluted, and 2- and 10-fold dilutions). The number of cell lines with viability ≥50% in the presence of selected dilution of the drug (CVS50) was used for comparison. In addition, 24 cell viability comparisons (four cell lines, two assays, and three exposure times) were made between latanoprost (Xalatan®) and each other solution at each dose. A comparison between the newly introduced tafluprost (Tapros®) with 0.01% benzalkonium chloride was also made. Results: The order of cell viability determined by CVS50 was Travatan Z® (travoprost with the SofZia system) > Tapros ≥ Travatan® (travoprost) = Xalatan > Rescula® (unoproston). This was consistent with the results of direct comparisons between Xalatan and the other drugs. There was no clear difference in cell viability between Tapros and benzalkonium chloride. Conclusions: Use of two assays, multiple cell lines, and various dilutions and exposure times provided a unique evaluation of cytotoxicity among ophthalmic solutions. CVS50 was useful for comparison of the cell viability of the solutions. PMID:20823934

  20. Effect of benzalkonium chloride on viability and energy metabolism in exponential- and stationary-growth-phase cells of Listeria monocytogenes

    NARCIS (Netherlands)

    Luppens, S.B.I.; Abee, T.; Oosterom, J.

    2001-01-01

    The difference in killing exponential- and stationary-phase cells of Listeria monocytogenes by benzalkonium chloride (BAC) was investigated by plate counting and linked to relevant bioenergetic parameters. At a low concentration of BAC (8 mg liter-1), a similar reduction in viable cell numbers was o

  1. Mixed species biofilms of Listeria monocytogenes and Lactobacillus plantarum show enhanced resistance to benzalkonium chloride and peracetic acid

    NARCIS (Netherlands)

    Veen, van der S.; Abee, T.

    2011-01-01

    We investigated the formation of single and mixed species biofilms of Listeria monocytogenes strains EGD-e and LR-991, with Lactobacillus plantarum WCFS1 as secondary species, and their resistance to the disinfectants benzalkonium chloride and peracetic acid. Modulation of growth, biofilm formation,

  2. In vivo wound-healing effects of novel benzalkonium chloride-loaded hydrocolloid wound dressing.

    Science.gov (United States)

    Jin, Sung Giu; Yousaf, Abid Mehmood; Jang, Sun Woo; Son, Mi-Won; Kim, Kyung Soo; Kim, Dong-Wuk; Li, Dong Xun; Kim, Jong Oh; Yong, Chul Soon; Choi, Han-Gon

    2015-05-01

    The purpose of this study was to evaluate the wound-healing effects of a novel benzalkonium chloride (BC)-loaded hydrocolloid wound dressing (HCD). A BC-loaded HCD was prepared with various constituents using a hot melting method, and its mechanical properties and antimicrobial activities were assessed. The in vivo wound healings of the BC-loaded HCD in various would models were evaluated in rats compared with a commercial wound dressing, Duoderm™. This BC-loaded HCD gave better skin adhesion, swelling, mechanical strength, and flexibility compared with the commercial wound dressing. It showed excellent antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. In addition, as compared with the commercial wound dressing, it showed more improved wound healings and tissue restoration effect on the excision, infection, and abrasion wounds in rats. Thus, this novel BC-loaded HCD would be an excellent alternative to the commercial wound dressing for treatment of various wounds.

  3. Corrosive Esophagitis with Benzalkonium Chloride in a Two Days Old Neonate.

    Science.gov (United States)

    Civan, Hasret Ayyildiz; Gulcu, Didem; Erkan, Tulay

    2016-09-01

    Benzalkonium chloride (BAC) is a caustic agent which is used in farms, homes and hospitals for cleaning skin and wounds as an antiseptic solution. It may lead to digestive system injuries in case of ingestion. We present a two-days-old newborn case which was carried to the emergency unit with complaints of poor breastfeeding, uneasiness and crying for 4-6 hours. Her mom confessed that she had given a spoon of 10% BAC solution for her cough. Initial laboratory tests were in normal ranges. A gastroscopy performed in the second hour of her admission revealed an hyperemic and edematous mucosa in the middle third of esophagus and a circumferential ulceration followed in the distal portion. Hereupon, a conservative treatment for 10 days was administered and the control gastroscopy demonstrated that the damage was almost totally improved. She was the youngest case with this etiology and successfully treated with conservative approach.

  4. Reduced virulence of Pseudomonas aeruginosa grown in the presence of benzalkonium chloride.

    Science.gov (United States)

    Adair, F W; Liauw, H L; Geftic, S G; Gelzer, J

    1975-01-01

    Resistant cells of Pseudomonas aeruginosa ATCC 9027 which were grown in the presence of 1 mg of benzalkonium chloride (BC) per ml caused only a mild conjunctivitis when they were dropped onto the scratched corneas of rabbits. In contrast, cells of the BC-sensitive parent strain induced a severe keratoconjunctivitis. In addition, the BC-grown cells also had a reduced capacity to produce kidney infections in mice as compared to the parent strain. BC-grown cells acted as weak complex antigens which conferred slight protection against lethal doses of BC-grown cells. No cross-protection to cells of the parent strain occurred. The data indicate that growth in the presence of BC results in cells with reduced virulence. Images PMID:809470

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

    Science.gov (United States)

    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.

  6. Antifungal activity of benzalkonium chloride, dettol , and chlorhexidine on opportunistic isolated fungi from the environment and operating rooms in private clinics of Tehran in 2011

    Directory of Open Access Journals (Sweden)

    Hossein Nowrozi

    2013-11-01

    Conclusion: Benzalkonium chloride and Dettol had a complete antifungal activity, but chlorhexidine was found to be the least effective agent.. Therefore, the tested concentrations give out their most fungicidal activity as disinfectants, if their durability is taken into account.

  7. Effects of Benzalkonium Chloride on THP-1 Differentiated Macrophages In Vitro

    Science.gov (United States)

    Michée, Sylvain; Brignole-Baudouin, Françoise; Riancho, Luisa; Rostene, William; Baudouin, Christophe; Labbé, Antoine

    2013-01-01

    Purpose To characterize the effects of benzalkonium chloride (BAK) in THP-1 differentiated cells in vitro. Methods Macrophages were obtained after differentiation of THP-1 cells, a human monocytic leukemia cell line. Macrophages were exposed for 24 h to 33 nM (10−5%) benzalkonium chloride (BAK), 10 nM dinitrochlorobenzene (DNCB), 100 ng/mL lipopolysaccharide (LPS), 5 ng/mL tumor necrosis factor alpha (TNF-α) or phosphate buffered saline (PBS) as controls. The expression of CD11b, CD11c, CD33 and CD54 was evaluated using immunohistochemistry and flow cytometry (FCM). Phagocytosis function was analyzed using carboxylate-modified fluorescent microspheres and quantified by FCM. Migration was evaluated in cocultures with conjunctival epithelial cells. Cytokine production was detected and quantified in culture supernatants using a human cytokine array. Results Stimulation of THP-1-derived macrophages with a low concentration of BAK increased CD11b and CD11c expression and decreased CD33. Macrophages exposed to BAK, LPS and TNF-α had increased phagocytosis. In contrast to LPS, BAK and TNF-α increased macrophage migration. Cytokines in supernatants of macrophages exposed to BAK revealed an increased release of CCL1, CCL4/MIP-1β, TNF-α, soluble CD54/ICAM-1 and IL-1β. Conclusion In vitro, BAK has a direct stimulating effect on macrophages, increasing phagocytosis, cytokine release, migration and expression of CD11b and CD11c. Long-term exposure to low concentrations of BAK should be considered as a stimulating factor responsible for inflammation through macrophage activation. PMID:23991114

  8. Effects of benzalkonium chloride on THP-1 differentiated macrophages in vitro.

    Directory of Open Access Journals (Sweden)

    Sylvain Michée

    Full Text Available PURPOSE: To characterize the effects of benzalkonium chloride (BAK in THP-1 differentiated cells in vitro. METHODS: Macrophages were obtained after differentiation of THP-1 cells, a human monocytic leukemia cell line. Macrophages were exposed for 24 h to 33 nM (10(-5% benzalkonium chloride (BAK, 10 nM dinitrochlorobenzene (DNCB, 100 ng/mL lipopolysaccharide (LPS, 5 ng/mL tumor necrosis factor alpha (TNF-α or phosphate buffered saline (PBS as controls. The expression of CD11b, CD11c, CD33 and CD54 was evaluated using immunohistochemistry and flow cytometry (FCM. Phagocytosis function was analyzed using carboxylate-modified fluorescent microspheres and quantified by FCM. Migration was evaluated in cocultures with conjunctival epithelial cells. Cytokine production was detected and quantified in culture supernatants using a human cytokine array. RESULTS: Stimulation of THP-1-derived macrophages with a low concentration of BAK increased CD11b and CD11c expression and decreased CD33. Macrophages exposed to BAK, LPS and TNF-α had increased phagocytosis. In contrast to LPS, BAK and TNF-α increased macrophage migration. Cytokines in supernatants of macrophages exposed to BAK revealed an increased release of CCL1, CCL4/MIP-1β, TNF-α, soluble CD54/ICAM-1 and IL-1β. CONCLUSION: In vitro, BAK has a direct stimulating effect on macrophages, increasing phagocytosis, cytokine release, migration and expression of CD11b and CD11c. Long-term exposure to low concentrations of BAK should be considered as a stimulating factor responsible for inflammation through macrophage activation.

  9. Cytotoxicity of prostaglandin analog eye drops preserved with benzalkonium chloride in multiple corneoconjunctival cell lines

    Directory of Open Access Journals (Sweden)

    Masahiko Ayaki

    2010-08-01

    Full Text Available Masahiko Ayaki1, Atsuo Iwasawa21Department of Ophthalmology, Saitama National Hospital, Wako, 2Department of Clinical Pathology, Showa University Fujigaoka Hospital, Yokohama, JapanPurpose: This study evaluated the cytotoxicity of five prostaglandin analog ophthalmic ­solutions on four ocular surface cell lines, ie, Chang (human conjunctiva, SIRC (rabbit cornea, RC-1 (rabbit cornea, and BCE C/D-1b (bovine cornea.Methods: Cell viability was measured by neutral red and MTT assays in cells treated for 10, 30, or 60 minutes with various doses of prostaglandins (undiluted, and 2- and 10-fold dilutions. The number of cell lines with viability ≥50% in the presence of selected dilution of the drug (CVS50 was used for comparison. In addition, 24 cell viability comparisons (four cell lines, two assays, and three exposure times were made between latanoprost (Xalatan® and each other solution at each dose. A comparison between the newly introduced tafluprost (Tapros® with 0.01% benzalkonium chloride was also made.Results: The order of cell viability determined by CVS50 was Travatan Z® (travoprost with the SofZia system> Tapros ≥ Travatan® (travoprost = Xalatan > Rescula® (unoproston. This was consistent with the results of direct comparisons between Xalatan and the other drugs. There was no clear difference in cell viability between Tapros and benzalkonium chloride.Conclusions: Use of two assays, multiple cell lines, and various dilutions and exposure times provided a unique evaluation of cytotoxicity among ophthalmic solutions. CVS50 was useful for comparison of the cell viability of the solutions.Keywords: glaucoma, cornea, cell viability score

  10. Efficacy and tolerability of benzalkonium chloride-free travoprost in glaucoma patients switched from benzalkonium chloride-preserved latanoprost or bimatoprost

    Directory of Open Access Journals (Sweden)

    García-Feijoo J

    2016-10-01

    Full Text Available Julian García-Feijoo,1 Francisco J Muñoz-Negrete,2 Douglas A Hubatsch,3 Gemma C Rossi4 On behalf of the study investigators 1Department of Ophthalmology, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Universidad Complutense, OFTARED, 2Hospital UniversItario Ramón y Cajal, Universidad de Alcalá, IRYCIS, OFTARED, Madrid, Spain; 3Alcon Laboratories, Inc., Fort Worth, TX, USA; 4Department of Ophthalmology, University Eye Clinic, IRCCS Policlinico San Matteo Foundation, Pavia, Italy Introduction: The preservative benzalkonium chloride (BAK is used to preserve several topical, intraocular pressure (IOP-lowering glaucoma medications but can cause tolerability concerns that may lead to decreased adherence to treatment and ultimately diminish the effectiveness of IOP control. The study aimed to determine the efficacy and tolerability of BAK-free travoprost preserved with polyquaternium-1 in glaucoma patients switched from BAK-preserved latanoprost or bimatoprost.Methods: This 12-week, open-label study was conducted in Europe between December 2011 and February 2013. We enrolled adult patients with open-angle glaucoma or ocular hypertension who were receiving BAK-preserved latanoprost 0.005% or bimatoprost 0.01% and, in the opinion of the investigator, would benefit from transition to BAK-free travoprost 0.004% preserved with polyquaternium-1 because of tolerability concerns. Assessments included IOP, proportion of patients with IOP ≤18 mmHg, ocular surface status, hyperemia, patient treatment preference, and adherence. Adverse events were recorded throughout the study.Results: Of the 202 patients screened, 187 patients were included in the intent-to-treat population (mean age, 66.6 years; range, 19–90 years. The mean IOP significantly reduced from baseline (17.0 mmHg to week 6 (mean change, -1.17 mmHg; P<0.001 and week 12 (-1.16 mmHg; P<0.001. At week 12, more patients achieved IOP ≤18 mmHg (81.2% versus 73.3% at

  11. Control of Listeria monocytogenes contamination in an Iberian pork processing plant and selection of benzalkonium chloride-resistant strains.

    Science.gov (United States)

    Ortiz, Sagrario; López, Victoria; Martínez-Suárez, Joaquín V

    2014-05-01

    The aims of this study were to characterize the different strains of Listeria monocytogenes collected at an Iberian pork processing plant and to investigate whether their specific characteristics were associated with prolonged survival in the plant. Using pulsed-field gel electrophoresis (PFGE), 29 PFGE types were previously identified during a three-year period. Eight of these PFGE types persisted in the plant during that period. In the present study, a subset of 29 PFGE type strains, which represented the 29 different PFGE types, was further characterized by assessing the potential virulence, and using motility, surface attachment, and antimicrobial susceptibility tests. After changing the disinfection procedures in the plant, the isolation rate of L. monocytogenes decreased, and only four of the 29 PFGE types, including three of the eight persistent PFGE types, were found the following year. These four "surviving" PFGE types included three from PCR serogroup IIa that were characterized by their low virulence mutations and low-level resistance to benzalkonium chloride (BAC). Furthermore, these PFGE types comprised the only BAC-resistant isolates found in the study, and they appear to have been selected due to the control of Listeria contamination. The resistance to increased sublethal concentrations of disinfectants may lead to prolonged survival of L. monocytogenes in food plants.

  12. Long-term exposure to benzalkonium chloride disinfectants results in change of microbial community structure and increased antimicrobial resistance.

    Science.gov (United States)

    Tandukar, Madan; Oh, Seungdae; Tezel, Ulas; Konstantinidis, Konstantinos T; Pavlostathis, Spyros G

    2013-09-03

    The effect of benzalkonium chlorides (BACs), a widely used class of quaternary ammonium disinfectants, on microbial community structure and antimicrobial resistance was investigated using three aerobic microbial communities: BACs-unexposed (DP, fed a mixture of dextrin/peptone), BACs-exposed (DPB, fed a mixture of dextrin/peptone and BACs), and BACs-enriched (B, fed only BACs). Long-term exposure to BACs reduced community diversity and resulted in the enrichment of BAC-resistant species, predominantly Pseudomonas species. Exposure of the two microbial communities to BACs significantly decreased their susceptibility to BACs as well as three clinically relevant antibiotics (penicillin G, tetracycline, ciprofloxacin). Increased resistance to BACs and penicillin G of the two BACs-exposed communities is predominantly attributed to degradation or transformation of these compounds, whereas resistance to tetracycline and ciprofloxacin is largely due to the activity of efflux pumps. Quantification of several key multidrug resistance genes showed a much higher number of copies of these genes in the DPB and B microbial communities compared to the DP community. Collectively, our findings indicate that exposure of a microbial community to BACs results in increased antibiotic resistance, which has important implications for both human and environmental health.

  13. [Simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis].

    Science.gov (United States)

    Song, Baohua; Ding, Xiaojing; Li, Jia; Wang, Zhi

    2012-09-01

    Benzalkonium chloride (BAC) is a mixture of alkyl substituted benzyl dimethylammonium chloride homologs (C12-BAC, C14-BAC and C16-BAC). Chlorhexidine acetate is a widely used effective component in compound chemical disinfectants. A method for the simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis (CE) was established. The CE analysis was carried out using an uncoated capillary with 50 microm i. d. and 37 cm total length. The running buffer was 150 mmol/L NaH2PO4-62.5 mmol/L H3PO4 (pH 2.5) containing 40% (v/v) acetonitrile. The sample medium was 50 mmol/L acetic acid-acetonitrile (1:1, v/v). The detection wavelength was 214 nm. The factors such as the buffer concentration and pH, the content of acetonitrile, which influenced the separation and accurate assay of compound chemical disinfectants were investigated in detail. The intra-day and inter-day precisions of the method were below 3. 0% and 3.7%, respectively. The limits of detection (LOD, signal to noise ratio (S/N) = 3) for chlorhexidine acetate, C12-BAC, Cl4-BAC and C16-BAC were 0. 3, 0.5, 0.5 and 0.5 mg/L, respectively. The limits of quantification (LOQ, S/N = 10) were 1.0, 1.5, 1.5, and 1.5 mg/L, respectively. The corrected peak area and the mass concentration of the four components mentioned above showed good linear relationships within the ranges of 1.0 - 400 mg/L, 1. 5 - 200 mg/L, 1.5 - 200 mg/L and 1.5 - 200 mg/L, with linear correlation coefficients (r) of 0.9995, 0.9998, 0.999 7 and 0.9998, respectively. The established method was used for the determination of the four disinfectants in the compound chemical disinfectants. The results were in good agreement with those obtained by the high performance liquid chromatographic method.

  14. Technical Note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

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    J. Gloël

    2015-08-01

    Full Text Available Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2 is routinely used for such preservation, but its handling and subsequent disposal incur significant risks and expense. Benzalkonium chloride (BAC has been used previously for freshwater samples. Here, we assess BAC as a less hazardous alternative microbial inhibitor for marine samples prior to the measurement of oxygen-to-argon (O2/Ar ratios, as used for the determination of plankton net community production. BAC at a concentration of 50 mg dm−3 inhibited microbial activity for at least three days in seawater with chlorophyll a (Chl a concentrations up to 1 mg m−3, possibly longer when Chl a concentrations were lower. BAC concentrations of 100 and 200 mg dm−3 were no more effective than 50 mg dm−3. With fewer risks to human health and the environment, and no requirement for expensive waste disposal, BAC could be a viable alternative to HgCl2 for short-term preservation of seawater samples, but is not a replacement for HgCl2 in the case of oxygen triple isotope analysis, which requires storage over weeks to months. In any event, further tests on a case-by-case basis should be undertaken if use of BAC was considered, since its inhibitory activity may depend on concentration and composition of the microbial community.

  15. Technical note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

    Science.gov (United States)

    Gloël, J.; Robinson, C.; Tilstone, G. H.; Tarran, G.; Kaiser, J.

    2015-12-01

    Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2) is routinely used for such preservation, but its handling and subsequent disposal incur environmental risks and significant expense. There is therefore a strong motivation to find less hazardous alternatives. Benzalkonium chloride (BAC) has been used previously as microbial inhibitor for freshwater samples. Here, we assess the use of BAC for marine samples prior to the measurement of oxygen-to-argon (O2 / Ar) ratios, as used for the determination of biological net community production. BAC at a concentration of 50 mg dm-3 inhibited microbial activity for at least 3 days in samples tested with chlorophyll a (Chl a) concentrations up to 1 mg m-3. BAC concentrations of 100 and 200 mg dm-3 were no more effective than 50 mg dm-3. With fewer risks to human health and the environment, and no requirement for expensive waste disposal, BAC could be a viable alternative to HgCl2 for short-term preservation of seawater samples, but is not a replacement for HgCl2 in the case of oxygen triple isotope analysis, which requires storage over weeks to months. In any event, further tests on a case-by-case basis should be undertaken if use of BAC was considered, since its inhibitory activity may depend on concentration and composition of the microbial community.

  16. Efficacy and tolerability of benzalkonium chloride-free travoprost in glaucoma patients switched from benzalkonium chloride-preserved latanoprost or bimatoprost

    Science.gov (United States)

    García-Feijoo, Julian; Muñoz-Negrete, Francisco J; Hubatsch, Douglas A; Rossi, Gemma C

    2016-01-01

    Introduction The preservative benzalkonium chloride (BAK) is used to preserve several topical, intraocular pressure (IOP)-lowering glaucoma medications but can cause tolerability concerns that may lead to decreased adherence to treatment and ultimately diminish the effectiveness of IOP control. The study aimed to determine the efficacy and tolerability of BAK-free travoprost preserved with polyquaternium-1 in glaucoma patients switched from BAK-preserved latanoprost or bimatoprost. Methods This 12-week, open-label study was conducted in Europe between December 2011 and February 2013. We enrolled adult patients with open-angle glaucoma or ocular hypertension who were receiving BAK-preserved latanoprost 0.005% or bimatoprost 0.01% and, in the opinion of the investigator, would benefit from transition to BAK-free travoprost 0.004% preserved with polyquaternium-1 because of tolerability concerns. Assessments included IOP, proportion of patients with IOP ≤18 mmHg, ocular surface status, hyperemia, patient treatment preference, and adherence. Adverse events were recorded throughout the study. Results Of the 202 patients screened, 187 patients were included in the intent-to-treat population (mean age, 66.6 years; range, 19–90 years). The mean IOP significantly reduced from baseline (17.0 mmHg) to week 6 (mean change, −1.17 mmHg; P<0.001) and week 12 (−1.16 mmHg; P<0.001). At week 12, more patients achieved IOP ≤18 mmHg (81.2% versus 73.3% at baseline), and ocular surface disease severity improved from baseline to week 12. Most patients preferred BAK-free travoprost (74.9%) versus their previous medication and were very confident in their adherence (84.1%). Reduced visual acuity and eye pruritus were the most common adverse events (2.5% each). Conclusion BAK-free travoprost 0.004% preserved with polyquaternium-1 was efficacious and well tolerated and may be an advantageous prostaglandin analog option for patients with open-angle glaucoma or ocular hypertension

  17. Amniotic membrane extract ameliorates benzalkonium chloride-induced dry eye in a murine model.

    Science.gov (United States)

    Xiao, Xinye; Luo, Pingping; Zhao, Hui; Chen, Jingyao; He, Hui; Xu, Yuxue; Lin, Zhirong; Zhou, Yueping; Xu, Jianjiang; Liu, Zuguo

    2013-10-01

    Human amniotic membrane (AM) is avascular but contains various beneficial bioactive factors, its extract (AE) is also effective in treating many ocular surface disorders. In this study, we for the first time evaluated the therapeutic effects of AE on dry eye induced by benzalkonium chloride in a BALB/c mouse model. Topical application of AE (1.5 and 3 μg/eye/day) resulted in significantly longer tear break-up time on Day 3 and 6, lower fluorescein staining scores on Day 3, and lower inflammatory index on Day 6. AE reduced corneal epithelial K10 expression, inflammatory infiltration, and levels of TNF-α, IL-1β and IL-6 in BAC treated mice than that in the control mice. Moreover, decreased TUNEL positive cells in cornea and increased goblet cells in conjunctiva were also observed in AE treated corneas. Finally, AE induced more Ki-67 positive cells in corneal epithelium of dry eye mouse. Taken together, our data provide further support for BAC induced dry eye model as a valuable for dry eye study and suggest a great potential for AE as a therapeutic agent in the clinical treatment of dry eye.

  18. Preservation of resin-dentin interfaces treated with benzalkonium chloride adhesive blends.

    Science.gov (United States)

    Sabatini, Camila; Ortiz, Pilar A; Pashley, David H

    2015-04-01

    Reducing collagen degradation within hybrid layers may contribute to the preservation of adhesive interfaces. This study evaluated the stability of resin-dentin interfaces treated with benzalkonium chloride (BAC)-modified adhesive blends and assessed collagen degradation in dentin matrices treated with BAC. The etch-and-rinse adhesive, Adper Single Bond Plus, modified with 0.5% and 1.0% BAC, was evaluated for microtensile bond strength (μTBS) and nanoleakage (NL) after 24 h and 1 yr. Thirty completely demineralized dentin beams from human molars were dipped for 60 s in deionized water (DW; control), or in 0.5% or 1.0% BAC, and then incubated in simulated body fluid (SBF). Collagen degradation was assessed by quantification of the dry mass loss and the amount of hydroxyproline (HYP) released from hydrolyzed specimens after 1 or 4 wk. Although all groups demonstrated a significant increase in NL after 1 yr, adhesive modified with 0.5% BAC showed stable bond strength after 1 yr (9% decrease) relative to the control (44% decrease). Significantly less HYP release and dry mass loss were observed for both 0.5% and 1.0% BAC relative to the control. This in vitro study demonstrates that BAC contributes to the preservation of resin-dentin bonds for up to 1 yr by reducing collagen degradation.

  19. Role of Efflux Pumps in Adaptation and Resistance of Listeria monocytogenes to Benzalkonium Chloride

    Science.gov (United States)

    Romanova, N. A.; Wolffs, P. F. G.; Brovko, L. Y.; Griffiths, M. W.

    2006-01-01

    In this study, potential mechanisms underlying resistance and adaptation to benzalkonium chloride (BC) in Listeria monocytogenes were investigated. Two groups of strains were studied. The first group consisted of strains naturally sensitive to BC which could be adapted to BC. The second group consisted of naturally resistant strains. For all adapted isolates, there was a correlation between the resistance to BC and ethidium bromide, but this was not the case for the naturally resistant isolates. To investigate the role of efflux pumps in adaptation or resistance, reserpine, an efflux pump inhibitor, was added to the strains. Addition of reserpine to the sensitive and adapted strains resulted in a decrease in the MIC for BC, whereas no such decrease was observed for the resistant strains, indicating that efflux pumps played no role in the innate resistance of certain strains of L. monocytogenes to this compound. Two efflux pumps (MdrL and Lde) have been described in L. monocytogenes. Studies showed low and intermediate levels of expression of the genes encoding the efflux pumps for two selected resistant strains, H7764 and H7962, respectively. Adaptation to BC of sensitive isolates of L. monocytogenes resulted in significant increases in expression of mdrl (P < 0.05), but no such increase was observed for lde for two adapted strains of L. monocytogenes, LJH 381 (P = 0.91) and C719 (P = 0.11). This indicates that the efflux pump Mdrl is at least partly responsible for the adaptation to BC. PMID:16672496

  20. Effects of artificial tears on rabbit ocular surface healing after exposure to benzalkonium chloride.

    Science.gov (United States)

    Zhang, Yuqiu; Cao, Hong; Lin, Tong; Gong, Lan

    2016-10-01

    The aim of the study was to observe the effect of different artificial tears on healing the drug-induced keratopathy. To this aim, 64 rabbits received topical administration of 0.01% benzalkonium chloride to establish models and were divided into four groups. The control group received ocular saline solution (Saline), while the others were treated with Refresh Plus® (RF), Hycosan® (H) and Systane® Ultra (SU). Surface abnormalities were examined daily using slit-lamp. Fluorescein staining, histopathological and transmission electron microscopic (TEM) examination were performed at day 0, 2 weeks, and 1 and 2 months. A significant difference was observed between RF and SU, but not between H and SU at 2 weeks. TEM examination revealed new microvilli close to the cavity surface, and the number of microvilli in SU was greater than in H at 2 weeks and 1 month. Based on the results, the effect in the SU group was the most significant. Eye drops with nontoxic preservative such as SU are an alternative to treat drug-induced keratopathy.

  1. Postadaptational Resistance to Benzalkonium Chloride and Subsequent Physicochemical Modifications of Listeria monocytogenes

    Science.gov (United States)

    To, Monica S.; Favrin, Stacy; Romanova, Nadya; Griffiths, Mansel W.

    2002-01-01

    Many studies have demonstrated that bacteria, including Listeria monocytogenes, are capable of adapting to disinfectants used in industrial settings after prolonged exposure to sublethal concentrations. However, the consequent alterations of the cell surface due to sanitizer adaptation of this pathogen are not fully understood. Two resistant and four sensitive L. monocytogenes strains from different sources were progressively subcultured with increasing sublethal concentrations of a surfactant, benzalkonium chloride (BC). To evaluate the effects of acquired tolerance to BC, parent and adapted strains were compared by using several morphological and physiological tests. Sensitive strains showed at least a fivefold increase in the MIC, while the MIC doubled for resistant strains after the adaptation period. The hydrophobicities of cells of parent and adapted strains were similar. Serological testing indicated that antigen types 1 and 4 were both present on the cell surface of adapted cells. The data suggest that efflux pumps are the major mechanism of adaptation in sensitive strains and are less important in originally resistant isolates. A different, unknown mechanism was responsible for the original tolerance of resistant isolates. In an originally resistant strain, there was a slight shift in the fatty acid profile after adaptation, whereas sensitive strains had similar profiles. Electron micrographs revealed morphological differences after adaptation. The changes in cell surface antigens, efflux pump utilization, and fatty acid profiles suggest that different mechanisms are used by resistant and sensitive strains for adaptation to BC. PMID:12406712

  2. Removal of Listeria monocytogenes dual-species biofilms using combined enzyme-benzalkonium chloride treatments.

    Science.gov (United States)

    Rodríguez-López, Pedro; Carballo-Justo, Alba; Draper, Lorraine A; Cabo, Marta L

    2017-01-01

    The effects of pronase (PRN), cellulase (CEL) or DNaseI alone or combined with benzalkonium chloride (BAC) against Listeria monocytogenes-carrying biofilms were assayed. The best removal activity against L. monocytogenes-Escherichia coli biofilms was obtained using DNaseI followed by PRN and CEL. Subsequently, a modified logistic model was used to quantify the combined effects of PRN or DNaseI with BAC. A better BAC performance after PRN compared to DNaseI eradicating L. monocytogenes was observed. In E. coli the effects were the opposite. Finally, effects of DNaseI and DNaseI-BAC treatments were compared against two different L. monocytogenes-carrying biofilms. DNaseI-BAC was more effective against L. monocytogenes when co-cultured with E. coli. Nonetheless, comparing the removal effects after BAC addition, these were higher in mixed-biofilms with Pseudomonas fluorescens. However, a high number of released viable cells was observed after combined treatments. These results open new perspectives of enzymes as an anti-biofilm strategy for environmental pathogen control.

  3. Determination of Benzalkonium Chloride in Nasal Drops by High-Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Danijela A. Kostić

    2012-01-01

    Full Text Available A high-performance liquid chromatography (HPLC system was used in the reversed phase mode for the determination of benzalkonium chloride (BKC in nosal drops. A Chromolit RP-18e, 100 x 4.6, (UM6077/035 column was used at 40 °C. The mobile phase, optimized through an experimental design, was a 70:30 (v/v mixture of 0.057M Na-heksansulphonate potassium, dihydrogen orthophosphate buffer (pH 2.9 and acetonitrile, pumped at a flow rate of 1.75 mL/min at maintaining column temperature at 40 °C. Maximum UV detection was achieved at 215 nm. The method was validated in terms of selectivity, linearity, repeatability, precision and accuracy. The method was successfully applied for the determination of BKC in a pharmaceutical formulation of nasal drop solution without any interference from common excipients and drug substance. All the validation parameters were within the acceptance range, concordant to ICH guidelines.

  4. Benzalkonium Chloride Accelerates the Formation of the Amyloid Fibrils of Corneal Dystrophy-associated Peptides*

    Science.gov (United States)

    Kato, Yusuke; Yagi, Hisashi; Kaji, Yuichi; Oshika, Tetsuro; Goto, Yuji

    2013-01-01

    Corneal dystrophies are genetic disorders resulting in progressive corneal clouding due to the deposition of amyloid fibrils derived from keratoepithelin, also called transforming growth factor β-induced protein (TGFBI). The formation of amyloid fibrils is often accelerated by surfactants such as sodium dodecyl sulfate (SDS). Most eye drops contain benzalkonium chloride (BAC), a cationic surfactant, as a preservative substance. In the present study, we aimed to reveal the role of BAC in the amyloid fibrillation of keratoepithelin-derived peptides in vitro. We used three types of 22-residue synthetic peptides covering Leu110-Glu131 of the keratoepithelin sequence: an R-type peptide with wild-type R124, a C-type peptide with C124 associated with lattice corneal dystrophy type I, and a H-type peptide with H124 associated with granular corneal dystrophy type II. The time courses of spontaneous amyloid fibrillation and seed-dependent fibril elongation were monitored in the presence of various concentrations of BAC or SDS using thioflavin T fluorescence. BAC and SDS accelerated the fibrillation of all synthetic peptides in the absence and presence of seeds. Optimal acceleration occurred near the CMC, which suggests that the unstable and dynamic interactions of keratoepithelin peptides with amphipathic surfactants led to the formation of fibrils. These results suggest that eye drops containing BAC may deteriorate corneal dystrophies and that those without BAC are preferred especially for patients with corneal dystrophies. PMID:23861389

  5. Ultrastructural Alterations Associated with the Growth of Resistant Pseudomonas aeruginosa in the Presence of Benzalkonium Chloride

    Science.gov (United States)

    Hoffmann, Hans-Peter; Geftic, Sam G.; Gelzer, Justus; Heymann, Hans; Adair, Frank W.

    1973-01-01

    Cells of Pseudomonas aeruginosa resistant to benzalkonium chloride (BC) underwent unique ultrastructural reorganizations when they were grown in the presence of 1 mg of BC/ml. The resistant cells usually contained a single, centrally positioned pseudovacuole. The pseudovacuole was surrounded by a diffuse substance that spread irregularly throughout the cytoplasm. The presence of the pseudovacuole seemed to cause a physical compartmentalization of the cytoplasm into random pockets of ribosomes and nuclear material. Contained within the pseudovacuole was a horseshoe-shaped, electron-dense body which was bounded by a trilaminar membrane 5.2 nm in width. These bodies averaged 77 nm when measured through the long axis. The surfaces of resistant cells were covered by an additional layer not found in sensitive cells. Thin sections of sensitive cells which had been treated with 1 mg of BC/ml showed little or no lysis. The cytoplasm appeared to be deeply stained and coagulated. Ribosomes were no longer distinctly visible. Although the cell wall remained intact, the cell membrane was dissolved and fragmented. BC-grown resistant cells could not be successfully stained by standard techniques; however, details were demonstrated with the aid of a combination of 1.5% glutaraldehyde, 1% osmium tetroxide, and 1% phosphotungstic acid prepared in 0.1 m sodium dimethylarsonate buffer (pH 6.8). Images PMID:4120070

  6. Determination of benzalkonium chloride in viscous ophthalmic drops of azithromycin by high-performance liquid chromatography *

    Science.gov (United States)

    Shen, Yan; Xu, Sheng-jie; Wang, Shi-chun; Tu, Jia-sheng

    2009-01-01

    A high-performance liquid chromatography (HPLC) system was used in the reversed phase mode for the determination of benzalkonium chloride (BKC) in azithromycin viscous ophthalmic drops. A Venusil-XBP(L)-C18 (150 mm×4.6 mm, 5 μm) column was used at 50 °C. The mobile phase consisted of a mixture of methanol-potassium phosphate (16:5, v/v). Two sample preparation methods were compared. The results suggested that, compared with an extraction procedure, a deproteinization procedure was much quicker and more convenient. Using the deproteinization procedure for sample preparation, calibration curves were linear in the range 5.0~50 μg/ml. The within-day and inter-day coefficients of variation were less than 10%. The average recoveries were determined as 96.70%, 98.52%, and 97.96% at concentrations of 10.0, 30.0, and 50.0 μg/ml, respectively. Variability in precision did not exceed 5%. In conclusion, this HPLC method using a simple sample treatment procedure appears suitable for monitoring BKC content in azithromycin viscous ophthalmic drops. PMID:19946951

  7. Detection of benzalkonium chloride resistance in community environmental isolates of staphylococci.

    Science.gov (United States)

    He, Gui-Xin; Landry, Michael; Chen, Huizhong; Thorpe, Conner; Walsh, Dennis; Varela, Manuel F; Pan, Hongmiao

    2014-05-01

    We isolated a total of 653 strains from 64 community environmental samples in Massachusetts, USA. Among these isolates, 9.65 % (63 strains) were benzalkonium chloride (BC)-resistant staphylococci. All BC-resistant strains were collected from surfaces upon which antibacterial wipes or antibacterial sprays containing 0.02-0.12 % BC had frequently been used in the fitness centres. However, isolates from surfaces upon which antibacterial wipes or antibacterial sprays had not been used were all sensitive to BC. All BC-resistant strains were also resistant to erythromycin, penicillin and ampicillin. In addition, 51 strains showed resistance to cetyltrimethylammonium bromide (CTAB), 15 strains showed resistance to chloramphenicol, 12 strains showed resistance to ciprofloxacin and four strains showed resistance to meticillin. Resistance gene analysis demonstrated that 41 strains contained qacA/B, 30 strains had qacC, 25 strains contained qacG, 16 strains had qacH and eight strains contained qacJ. These data indicate that application of BC is associated with environmental staphylococcal antimicrobial resistance.

  8. Ion mobility spectrometry as a fast analytical tool in benzalkonium chloride homologs determination.

    Science.gov (United States)

    Gallart-Mateu, D; Armenta, S; Esteve-Turrillas, F A; de la Guardia, M

    2017-03-01

    A novel procedure is proposed for the determination by ion mobility spectrometry (IMS) of C12, C14 and C16 benzalkonium chloride (BAC) homologs. The proposed method requires minimum sample treatment and the measurement was made in less than one minute. A high sensitivity was obtained for BAC determination by IMS with limit of detection values from 37 to 69µgL(-1). Accuracy of the proposed methodology was evaluated through the analysis of aqueous and alcoholic samples spiked with BAC at concentration levels from 0.002% to 20% (w/v), providing recovery values from 91% to 104%. BAC was determined in sanitary alcohols, nasal sprays, postharvest products, algaecides, and treated swimming pool water. Results obtained by the proposed IMS methodology were statistically comparable to those provided by a liquid chromatography-ultraviolet (LC-UV) reference methodology. The Green Certificate evaluation of the proposed IMS methodology provided 91 score points in the Eco-Scale as compared with 77 for LC-UV method.

  9. Efflux pump-mediated benzalkonium chloride resistance in Listeria monocytogenes isolated from retail food.

    Science.gov (United States)

    Jiang, Xiaobing; Yu, Tao; Liang, Yu; Ji, Shengdong; Guo, Xiaowei; Ma, Jianmin; Zhou, Lijun

    2016-01-18

    In this study, efflux pump-mediated benzalkonium chloride (BC) resistance, including plasmid-encoded (Qac protein family and BcrABC) and chromosome-borne efflux pumps, was investigated in Listeria monocytogenes from retail food in China. Among the 59 L. monocytogenes strains, 13 (22.0%) strains were resistant to BC. The PCR results showed that bcrABC was harbored by 2 of 13 BC resistant strains. However, none of the qac genes were detected among the 59 strains. The bcrABC was absent in both of the plasmid cured strains, indicating that this BC resistance determinant was plasmid-encoded in the two bcrABC-positive strains. In the presence of reserpine, most of the bcrABC-negative strains had decreases in the MICs of BC, suggesting the existence of other efflux pumps and their role in BC resistance. After exposed to reserpine, the reduction in BC MICs was observed in the two cured strains, indicating that efflux pumps located on chromosome was also involved in BC resistance. Our findings suggest that food products may act as reservoirs for BC resistant isolates of L. monocytogenes and plasmid- and chromosome-encoded efflux pumps could mediate the BC resistance of L. monocytogenes, which is especially relevant to the adaption of this organism in food-related environments with frequent BC use.

  10. Hyperosmolarity and Benzalkonium Chloride Differently Stimulate Inflammatory Markers in Conjunctiva-Derived Epithelial Cells in vitro.

    Science.gov (United States)

    Warcoin, Elise; Clouzeau, Chloé; Roubeix, Christophe; Raveu, Anne-Laure; Godefroy, David; Riancho, Luisa; Baudouin, Christophe; Brignole-Baudouin, Françoise

    2016-12-10

    Tear hyperosmolarity is known to cause ocular surface inflammation in dry eye syndrome. Benzalkonium chloride (BAK), an eyedrop preservative, is known to induce dry eye in long-term-treated patients. Analyzing the modulation of the proinflammatory potential of hyperosmolarity in the presence of BAK on the conjunctiva could give new insights into the effect of this preservative on the disease. In a hyperosmolar model on a conjunctiva-derived cell line, and in the presence of BAK, we evaluated key inflammatory markers [CCL2, IL-8, IL-6, macrophage migration inhibitory factor (MIF) and intercellular adhesion molecule (ICAM)-1] as well as the osmoprotectant element nuclear factor of activated T cells (NFAT)5 using ELISA, RT-qPCR or immunofluorescence staining. Hyperosmolarity highly stimulated CCL2 and NFAT5 in these cells. BAK alone only increased IL-6 expression. The stress-combined condition stimulated CCL2, NFAT5, MIF and IL-8 secretion. ICAM-1 was not modulated by any of the conditions tested. In this model, hyperosmolarity and BAK induced the release of different proinflammatory mediators, and, when combined, they lead to the release of additional inflammatory cytokines. This in vitro study highlights the importance of avoiding long-term ophthalmic treatments containing BAK, as tear film hyperosmolarity can be a result of its detergent action.

  11. Study of the hormetic effect of disinfectants chlorhexidine, povidone iodine and benzalkonium chloride.

    Science.gov (United States)

    Morales-Fernández, L; Fernández-Crehuet, M; Espigares, M; Moreno, E; Espigares, E

    2014-01-01

    The study of the dose-response relationship of disinfectants is of great importance in treating infection, the objective being to use concentrations above the minimal bactericidal concentration (MBC). Below these concentrations, the bacteriostatic or bactericidal effect may be insufficient. Moreover, at low concentrations, a hormetic effect may be observed, producing a stimulation of growth instead of inhibitory action. Hormesis is not well known in the context of antimicrobial substances. This study investigates the possible existence of a hormetic effect in three commonly used antiseptics-chlorhexidine digluconate, povidone iodine and benzalkonium chloride-on strains of reference of Staphylococcus aureus and Pseudomonas aeruginosa. Growth curves were determined for different concentrations of the disinfectants. The variables studied-concentration of disinfectant, instantaneous growth rate and number of generations-were analysed using linear, quadratic and cubic models to adjust for the variables. The three disinfectants tested show a significant hormetic effect with P. aeruginosa and a less significant effect with S. aureus. These findings point to a dose-response effect that is not linear at low concentrations, while hormetic effects observed at some low concentrations result in greater bacterial growth. In infected wounds, materials or surfaces where microorganisms may occupy zones of difficult access for a disinfectant, the hormetic effect may have important consequences.

  12. Similar Microbial Consortia and Genes Are Involved in the Biodegradation of Benzalkonium Chlorides in Different Environments.

    Science.gov (United States)

    Ertekin, Emine; Hatt, Janet K; Konstantinidis, Konstantinos T; Tezel, Ulas

    2016-04-19

    Benzalkonium chlorides (BACs) are emerging pollutants. Identification of microorganisms and the genes involved in the biodegradation of BACs is crucial for better understanding the fate of BACs in the environment and developing treatment strategies. Four microbial communities degrading BACs were developed from sewage (SEW), activated sludge (AS), soil (SOIL) and sea sediment (SEA) samples. According to 16S rRNA pyrosequencing and shotgun metagenome sequencing analyses, the most abundant species represented uncharacterized members of the Pseudomonas and Achromobacter genera. BAC biotransformation rates of the enriched microbial communities were 2.8, 3.2, 17.8, and 24.3 μM hr(-1) for SEA, AS, SOIL, and SEW, respectively, and were positively correlated with the relative abundance of a particular Pseudomonas sp. strain, BIOMIG1. The strain BIOMIG1 mineralizes BACs at a rate up to 2.40 μmol hr(-1) 10(-11) cells. Genomes of four BAC degrading and nondegrading BIOMIG1 phenotypes were sequenced and differentially compared with each other. As a result, a gene cluster encoding for transporters, an integrase and a dioxygenase were involved in BAC biotransformation. Our results suggest that BIOMIG1 plays a key role on the fate of BACs in the environment and genes, other than those reported to date, are involved in BAC biotransformation in various habitats.

  13. Synthesis, Structure and Antimicrobial Properties of Novel Benzalkonium Chloride Analogues with Pyridine Rings.

    Science.gov (United States)

    Brycki, Bogumił; Małecka, Izabela; Koziróg, Anna; Otlewska, Anna

    2017-01-13

    Quaternary ammonium compounds (QACs) are a group of compounds of great economic significance. They are widely used as emulsifiers, detergents, solubilizers and corrosion inhibitors in household and industrial products. Due to their excellent antimicrobial activity QACs have also gained a special meaning as antimicrobials in hospitals, agriculture and the food industry. The main representatives of the microbiocidal QACs are the benzalkonium chlorides (BACs), which exhibit biocidal activity against most bacteria, fungi, algae and some viruses. However, the misuses of QACs, mainly at sublethal concentrations, can lead to an increasing resistance of microorganisms. One of the ways to avoid this serious problem is the introduction and use of new biocides with modified structures instead of the biocides applied so far. Therefore new BAC analogues P13-P18 with pyridine rings were synthesized. The new compounds were characterized by NMR, FT-IR and ESI-MS methods. PM3 semiempirical calculations of molecular structures and the heats of formation of compounds P13-P18 were also performed. Critical micellization concentrations (CMCs) were determined to characterize the aggregation behavior of the new BAC analogues. The antimicrobial properties of novel QACs were examined by determining their minimal inhibitory concentration (MIC) values against the fungi Aspergillus niger, Candida albicans, Penicillium chrysogenum and bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The MIC values of N,N-dimethyl-N-(4-methylpyridyl)-N-alkylammonium chlorides for fungi range from 0.1 to 12 mM and for bacteria, they range from 0.02 to 6 mM.

  14. Synthesis, Structure and Antimicrobial Properties of Novel Benzalkonium Chloride Analogues with Pyridine Rings

    Directory of Open Access Journals (Sweden)

    Bogumił Brycki

    2017-01-01

    Full Text Available Quaternary ammonium compounds (QACs are a group of compounds of great economic significance. They are widely used as emulsifiers, detergents, solubilizers and corrosion inhibitors in household and industrial products. Due to their excellent antimicrobial activity QACs have also gained a special meaning as antimicrobials in hospitals, agriculture and the food industry. The main representatives of the microbiocidal QACs are the benzalkonium chlorides (BACs, which exhibit biocidal activity against most bacteria, fungi, algae and some viruses. However, the misuses of QACs, mainly at sublethal concentrations, can lead to an increasing resistance of microorganisms. One of the ways to avoid this serious problem is the introduction and use of new biocides with modified structures instead of the biocides applied so far. Therefore new BAC analogues P13–P18 with pyridine rings were synthesized. The new compounds were characterized by NMR, FT-IR and ESI-MS methods. PM3 semiempirical calculations of molecular structures and the heats of formation of compounds P13–P18 were also performed. Critical micellization concentrations (CMCs were determined to characterize the aggregation behavior of the new BAC analogues. The antimicrobial properties of novel QACs were examined by determining their minimal inhibitory concentration (MIC values against the fungi Aspergillus niger, Candida albicans, Penicillium chrysogenum and bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The MIC values of N,N-dimethyl-N-(4-methylpyridyl-N-alkylammonium chlorides for fungi range from 0.1 to 12 mM and for bacteria, they range from 0.02 to 6 mM.

  15. Development and validation of a rapid ultra-high performance liquid chromatography method for the assay of benzalkonium chloride using a quality-by-design approach.

    Science.gov (United States)

    Mallik, Rangan; Raman, Srividya; Liang, Xiaoli; Grobin, Adam W; Choudhury, Dilip

    2015-09-25

    A rapid robust reversed-phase UHPLC method has been developed for the analysis of total benzalkonium chloride in preserved drug formulation. A systematic Quality-by-Design (QbD) method development approach using commercial, off the shelf software (Fusion AE(®)) has been used to optimize the column, mobile phases, gradient time, and other HPLC conditions. Total benzalkonium chloride analysis involves simple sample preparation. The method uses gradient elution from an ACE Excel 2 C18-AR column (50mm×2.1mm, 2.0μm particle size), ammonium phosphate buffer (pH 3.3; 10mM) as aqueous mobile phase and methanol/acetonitrile (85/15, v/v) as the organic mobile phase with UV detection at 214nm. Using these conditions, major homologs of the benzalkonium chloride (C12 and C14) have been separated in less than 2.0min. The validation results confirmed that the method is precise, accurate and linear at concentrations ranging from 0.025mg/mL to 0.075mg/mL for total benzalkonium chloride. The recoveries ranged from 99% to 103% at concentrations from 0.025mg/mL to 0.075mg/mL for total benzalkonium chloride. The validation results also confirmed the robustness of the method as predicted by Fusion AE(®).

  16. Reasoned opinion on the dietary risk assessment for proposed temporary maximum residue levels (MRLs of didecyldimethylammonium chloride (DDAC and benzalkonium chloride (BAC

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2014-04-01

    Full Text Available EFSA was requested by the European Commission to perform a dietary exposure assessment for the proposed temporary maximum residue levels (MRLs for didecyldimethylammonium chloride (DDAC and benzalkonium chloride (BAC (0.1 mg/kg, respectively, for all food commodities covered by the EU MRL legislation. Based on the information, EFSA did not identify potential consumer health risks for these proposed MRLs. Thus, the proposed MRLs are considered to be sufficiently protective. However, due to the limited data available, the risk assessments are affected by a high degree of uncertainty.

  17. Bactericidal Property of the Benzalkonium Chloride in Industrial Circulating Water%洁儿灭在工业循环水中的杀菌性能研究

    Institute of Scientific and Technical Information of China (English)

    孙彩霞; 陈燕敏; 吴晋英; 黄长山

    2016-01-01

    In the thesis,the bactericidal property of benzalkonium chloride was tested by the method of plate counting. The bactericidal effciency was improved with increasing the concentration of benzalkonium chloride. At the same time the bacterial agent which prepared by the benzalkonium chloride had a better scale inbibtion effect , and could be sately applied to industrial circulating water pipeline system.%通过平板计数法考察了不同浓度的洁儿灭对工业循环水中异养菌的杀菌性能,结果显示,洁儿灭杀菌效率随着浓度的增加而增加,且由洁儿灭配制而成的杀菌剂阻垢性能较好,能安全地应用到工业循环水管道系统中。

  18. A Time-Limited and Partially Reversible Model of Hypoganglionosis Induced by Benzalkonium Chloride Treatment.

    Science.gov (United States)

    Yu, Hui; Pan, Weikang; Wang, HuaiJie; Gao, Ya

    2016-05-01

    Serosal application of benzalkonium chloride (BAC) has been previously applied to produce a model of aganglionosis; however, confusion remains regarding the extent of chemical ablation of enteric myenteric plexus after BAC treatment. The time sequence of BAC-induced effects on the myenteric plexus of the rat colon was determined and followed the morphologic changes. After sacrifice of animals 7, 14, 28, 56, 84 or 168 days postintervention, colonic tissue samples were removed, fixed in formalin, and cut into 5-μm longitudinal sections for histological analysis. The neural analysis was used to re-evaluate BAC treatments for the appropriate model. Compared with rats in sham groups, rats in 0.1 %-30-min BAC group maintained only 15.27 ± 4.80 % of ganglia per section in a 1-cm/5-μm slice and 11.76 ± 2.30 % of ganglionic cells after 28 days, the lower and stable number of ganglionic cells between Day 7 and 84 (from 11.67 ± 2.10 to 19.05 ± 5.10 %). Although an increase, ganglionic cell numbers did not recover at Day168 when compared with the numbers in sham groups. The results showed that characteristics of rats in the 0.1 %-30-min BAC group between Day 7 and 84 most closely kept in stable state, suggesting that these treatment parameters are ideal for producing a hypoganglia model of hypoganglionosis.

  19. A mouse dry eye model induced by topical administration of benzalkonium chloride

    Science.gov (United States)

    Lin, Zhirong; Liu, Xiaochen; Zhou, Tong; Wang, Yihui; Bai, Li; He, Hui

    2011-01-01

    Purpose To develop a dry eye model of mouse induced by topical administration of benzalkonium chloride (BAC) and investigate the possible mechanisms. Methods BAC at concentration of 0.2% was applied to the mouse ocular surface for 7 days. Phenol red thread tear test, tear break-up time (BUT) test, corneal inflammatory index scoring, fluorescein and rose bengal test were performed to evaluate the toxic effects of BAC on the ocular surface. Global specimens were collected on day (D) 7 and labeled with a series of antibodies including cytokeratin 10 (K10) and mucin 5AC (MUC5AC). Apoptosis of ocular surface epithelium was evaluated by in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Histologic analysis and transmission electron microscopy (TEM) were performed on D7. Results BAC at a concentration of 0.2% successfully induced a dry eye condition with decreased tear volume and BUTs, increased corneal fluorescein and rose bengal scores. The Inflammatory index was increased in accompanyment with higher tumor necrosis factor-α (TNF-α) expression and more inflammatory infiltration in the cornea. Immunolabeling revealed positive K10 expression in BAC-treated corneal epithelium and fewer MUC5AC-positive cells in the BAC-treated conjunctival fornix. TUNEL assay showed more apoptotic cells in the corneal basal epithelium. TEM showed that the size and intervals of the microvillis were both reduced in the corneal epithelium. Conclusions Topical administration of 0.2% BAC in mouse induces changes resembling that of dry eye syndrome in humans, and thus, represents a novel model of dry eye. PMID:21283525

  20. Toxic effect in the lungs of rats after inhalation exposure to benzalkonium chloride

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    Radosław Świercz

    2013-08-01

    Full Text Available Background: Benzalkonium chloride (BAC is a quaternary ammonium compound (QAC toxic to microorganisms. Inhalation is one of the major possible routes of human exposure to BAC. Materials and Methods: Experiments were performed on female Wistar rats. The rats were exposed to aerosol of BAC water solution at the target concentration of 0 (control group and 35 mg/m3 for 5 days (6 h/day and, after a 2-week interval, the animals were challenged (day 21 with BAC aerosol at the target concentration of 0 (control group and 35 mg/m3 for 6 h. Results: Compared to the controls, the animals exposed to BAC aerosol were characterized by lower food intake and their body weight was significantly smaller. As regards BAC-exposed group, a significant increase was noted in relative lung mass, total protein concentration, and MIP-2 in BALF both directly after the termination of the exposure and 18 h afterwards. Significantly higher IL-6 and IgE concentrations in BALF and a decrease in the CC16 concentration in BALF were found in the exposed group immediately after the exposure. The leukocyte count in BALF was significantly higher in the animals exposed to BAC aerosol compared to the controls. In the lungs of rats exposed to BAC the following effects were observed: minimal perivascular, interstitial edema, focal aggregates of alveolar macrophages, interstitial mononuclear cell infiltrations, thickened alveolar septa and marginal lipoproteinosis. Conclusion: Inhalation of BAC induced a strong inflammatory response and a damage to the blood-air barrier. Reduced concentrations of CC16, which is an immunosuppressive and anti-inflammatory protein, in combination with increased IgE concentrations in BALF may be indicative of the immuno-inflammatory response in the animals exposed to BAC aerosol by inhalation. Histopathological examinations of tissue samples from the BAC-exposed rats revealed a number of pathological changes found only in the lungs.

  1. Corneal alternations induced by topical application of benzalkonium chloride in rabbit.

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    Wensheng Chen

    Full Text Available Benzalkonium chloride (BAC is the most common preservative in ophthalmic preparations. Here, we investigated the corneal alternations in rabbits following exposure to BAC. Twenty-four adult male New Zealand albino rabbits were randomly divided into three groups. BAC at 0.01%, 0.05%, or 0.1% was applied twice daily to one eye each of rabbits for 4 days. The contralateral untreated eyes were used as control. Aqueous tear production and fluorescein staining scores of BAC-treated eyes were compared with those of controls. The structure of the central cornea was examined by in vivo confocal microscopy. Expression of mucin-5 subtype AC (MUC5AC in conjunctiva was detected by immunostainig on cryosections. Corneal barrier function was assessed in terms of permeability to carboxy fluorescein (CF. The distribution and expression of ZO-1, a known marker of tight junction, and reorganization of the perijunctional actomyosin ring (PAMR were examined by immunofluorescence analysis. Although there were no significant differences between control and BAC-treated eyes in Schirmer scores, corneal fluorescein scores and the number of conjunctival MUC5AC staining cells, in vivo confocal microscopy revealed significant epithelial and stromal defects in all BAC-treated corneas. Moreover, BAC at 0.1% resulted in significant increases in central corneal thickness and endothelial CF permeability, compared with those in control eyes, and endothelial cell damage with dislocation of ZO-1 and disruption of PAMR. Topical application of BAC can quickly impair the whole cornea without occurrence of dry eye. A high concentration of BAC breaks down the barrier integrity of corneal endothelium, concomitant with the disruption of PAMR and remodeling of apical junctional complex in vivo.

  2. Corneal Alternations Induced by Topical Application of Benzalkonium Chloride in Rabbit

    Science.gov (United States)

    Chen, Wensheng; Li, Zhiyuan; Hu, Jiaoyue; Zhang, Zhenhao; Chen, Lelei; Chen, Yongxiong; Liu, Zuguo

    2011-01-01

    Benzalkonium chloride (BAC) is the most common preservative in ophthalmic preparations. Here, we investigated the corneal alternations in rabbits following exposure to BAC. Twenty-four adult male New Zealand albino rabbits were randomly divided into three groups. BAC at 0.01%, 0.05%, or 0.1% was applied twice daily to one eye each of rabbits for 4 days. The contralateral untreated eyes were used as control. Aqueous tear production and fluorescein staining scores of BAC-treated eyes were compared with those of controls. The structure of the central cornea was examined by in vivo confocal microscopy. Expression of mucin-5 subtype AC (MUC5AC) in conjunctiva was detected by immunostainig on cryosections. Corneal barrier function was assessed in terms of permeability to carboxy fluorescein (CF). The distribution and expression of ZO-1, a known marker of tight junction, and reorganization of the perijunctional actomyosin ring (PAMR) were examined by immunofluorescence analysis. Although there were no significant differences between control and BAC-treated eyes in Schirmer scores, corneal fluorescein scores and the number of conjunctival MUC5AC staining cells, in vivo confocal microscopy revealed significant epithelial and stromal defects in all BAC-treated corneas. Moreover, BAC at 0.1% resulted in significant increases in central corneal thickness and endothelial CF permeability, compared with those in control eyes, and endothelial cell damage with dislocation of ZO-1 and disruption of PAMR. Topical application of BAC can quickly impair the whole cornea without occurrence of dry eye. A high concentration of BAC breaks down the barrier integrity of corneal endothelium, concomitant with the disruption of PAMR and remodeling of apical junctional complex in vivo. PMID:22022526

  3. Resistance to benzalkonium chloride, peracetic acid and nisin during formation of mature biofilms by Listeria monocytogenes.

    Science.gov (United States)

    Saá Ibusquiza, P; Herrera, J J R; Cabo, M L

    2011-05-01

    Increase of resistance to the application of benzalkonium chloride (BAC), peracetic acid (PA) and nisin during biofilm formation at 25 °C by three strains of Listeria monocytogenes (CECT 911, CECT 4032, CECT 5873 and BAC-adapted CECT 5873) in different scenarios was compared. For this purpose, resistance after 4 and 11-days of biofilm formation was quantified in terms of lethal dose 90% values (LD(90)), determined according with a dose-response logistic mathematical model. Microscopic analyses after 4 and 11-days of L. monocytogenes biofilm formation were also carried out. Results demonstrated a relation between the microscopic structure and the resistance to the assayed biocides in matured biofilms. The worst cases being biofilms formed by the strain 4032 (in both stainless steel and polypropylene), which showed a complex "cloud-type" structure that correlates with the highest resistance of this strain against the three biocides during biofilm maturation. However, that increase in resistance and complexity appeared not to be dependent on initial bacterial adherence, thus indicating mature biofilms rather than planctonic cells or early-stage biofilms must be considered when disinfection protocols have to be optimized. PA seemed to be the most effective of the three disinfectants used for biofilms. We hypothesized both its high oxidizing capacity and low molecular size could suppose an advantage for its penetration inside the biofilm. We also demonstrated that organic material counteract with the biocides, thus indicating the importance of improving cleaning protocols. Finally, by comparing strains 5873 and 5873 adapted to BAC, several adaptative cross-responses between BAC and nisin or peracetic acid were identified.

  4. Biopolymer-modified graphite oxide nanocomposite films based on benzalkonium chloride-heparin intercalated in graphite oxide

    Energy Technology Data Exchange (ETDEWEB)

    Meng Na; Zhou Ninglin; Shen Jian [Jiangsu Engineering Research Center for Biomedical Function Materials, Nanjing Normal University, Nanjing 210046 (China); Zhang Shuangquan, E-mail: zhouninglin@njnu.edu.cn, E-mail: jshen@njnu.edu.cn, E-mail: shuangquanz@yahoo.com [Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210046 (China)

    2010-05-07

    Heparin is a potent anticoagulant agent that interacts strongly with antithrombin III to prevent the formation of fibrin clots. In the present work, poly(dimethylsiloxane)(PDMS)/graphite oxide-benzalkonium chloride-heparin (PDMS/modified graphite oxide) nanocomposite films were obtained by the solution intercalation technique as a possible drug delivery system. The heparin-benzalkonium chloride (BAC-HEP) was intercalated into graphite oxide (GO) layers to form GO-BAC-HEP (modified graphite oxide). Nanocomposite films were characterized by XRD, SEM, TEM, ATR-FTIR and TGA. The modified graphite oxide was observed to be homogeneously dispersed throughout the PDMS matrix. The effect of modified graphite oxide on the mechanical properties of the nanocomposite film was investigated. When the modified graphite oxide content was lower than 0.2 wt%, the nanocomposites showed excellent mechanical properties. Furthermore, nanocomposite films become delivery systems that release heparin slowly to make the nanocomposite films blood compatible. The in vitro studies included hemocompatibility testing for effects on platelet adhesion, platelet activation, plasma recalcification profiles, and hemolysis. Results from these studies showed that the anticoagulation properties of PDMS/GO-BCA-HEP nanocomposite films were greatly superior to those for no treated PDMS. Cell culture assay indicated that PDMS/GO-BCA-HEP nanocomposite films showed enhanced cell adhesion.

  5. Biopolymer-modified graphite oxide nanocomposite films based on benzalkonium chloride-heparin intercalated in graphite oxide

    Science.gov (United States)

    Meng, Na; Zhang, Shuang-Quan; Zhou, Ning-Lin; Shen, Jian

    2010-05-01

    Heparin is a potent anticoagulant agent that interacts strongly with antithrombin III to prevent the formation of fibrin clots. In the present work, poly(dimethylsiloxane)(PDMS)/graphite oxide-benzalkonium chloride-heparin (PDMS/modified graphite oxide) nanocomposite films were obtained by the solution intercalation technique as a possible drug delivery system. The heparin-benzalkonium chloride (BAC-HEP) was intercalated into graphite oxide (GO) layers to form GO-BAC-HEP (modified graphite oxide). Nanocomposite films were characterized by XRD, SEM, TEM, ATR-FTIR and TGA. The modified graphite oxide was observed to be homogeneously dispersed throughout the PDMS matrix. The effect of modified graphite oxide on the mechanical properties of the nanocomposite film was investigated. When the modified graphite oxide content was lower than 0.2 wt%, the nanocomposites showed excellent mechanical properties. Furthermore, nanocomposite films become delivery systems that release heparin slowly to make the nanocomposite films blood compatible. The in vitro studies included hemocompatibility testing for effects on platelet adhesion, platelet activation, plasma recalcification profiles, and hemolysis. Results from these studies showed that the anticoagulation properties of PDMS/GO-BCA-HEP nanocomposite films were greatly superior to those for no treated PDMS. Cell culture assay indicated that PDMS/GO-BCA-HEP nanocomposite films showed enhanced cell adhesion.

  6. Effects of chronic exposure to benzalkonium chloride in Oncorhynchus mykiss: cholinergic neurotoxicity, oxidative stress, peroxidative damage and genotoxicity.

    Science.gov (United States)

    Antunes, S C; Nunes, B; Rodrigues, S; Nunes, R; Fernandes, J; Correia, A T

    2016-07-01

    Benzalkonium chloride (BAC) is one of the most used conservatives in pharmaceutical preparations. However, its use is limited to a small set of external use formulations, due to its high toxicity. Benzalkonium chloride effects are related to the potential exertion of deleterious effects, mediated via oxidative stress and through interaction with membrane enzymes, leading to cellular damage. To address the ecotoxicity of this specific compound rainbow trouts were chronically exposed to BAC at environmental relevant concentrations (ranging from 0.100 to 1.050mg/L), and the biological response of cholinergic neurotoxicity, modulation of the antioxidant defense, phase II metabolism, lipid peroxidation and genotoxicity was studied. The obtained results showed a dual pattern of antioxidant response, with significant alterations in catalase activity (starting at 0.180mg/L), and lipid peroxidation, for intermediate (0.180 and 0.324mg/L) concentrations. No significant alterations occurred for glutathione-S-transferases activity. An unexpected increased of the acetylcholinesterase activity was also recorded for the individuals exposed to higher concentrations of BAC (starting at 0.180mg/L). Furthermore, exposure to BAC resulted in the establishment of genotoxic alterations, observable (for the specific case of the comet assay results) for all tested BAC concentrations. However, and considering that the oxidative response was not devisable, other mechanisms may be involved in the genotoxic effects reported here.

  7. Tn6188 - a novel transposon in Listeria monocytogenes responsible for tolerance to benzalkonium chloride.

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    Anneliese Müller

    Full Text Available 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 ΔqacH strains had lower BC MICs than wildtype strains. In conclusion, our results provide evidence that Tn6188 is responsible for BC tolerance in various L

  8. Toxicity of antiglaucoma drugs with and without benzalkonium chloride to cultured human corneal endothelial cells

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    Masahiko Ayaki

    2010-10-01

    Full Text Available Masahiko Ayaki1, Atsuo Iwasawa2, Yoichi Inoue31Department of Ophthalmology, Saitama National Hospital, Wako, Japan; 2Life Particle Interaction Engineering Creation, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan; 3Department of Ophthalmology, Olympia Eye Hospital, Tokyo, JapanPurpose: The toxicity of antiglaucoma medications to ocular surface cells has been evaluated extensively; however, the toxicity to corneal endothelial cells (CECs remains elusive. Our aim is to evaluate the toxicity of antiglaucoma medications to CECs using an in vitro toxicity assay.Methods: Primary cultures of human (H CECs derived from eye bank specimens were established. Following exposure of HCECs to test solutions for 10, 30, or 60 minutes, or 48 hours, we measured cell viability using a WST-1 assay. Test solutions were diluted in culture media and included 0.5% Timoptol®, preservative-free 0.5% timolol maleate, 1% Trusopt®, preservative-free 1% dorzolamide, Travatan®, Travatan Z®, Xalatan®, and benzalkonium chloride (BAK. To assess cell viability, the value of the test culture well after treatment was expressed as a percentage of that of the control well. Toxicity of each solution was compared using the cell viability score (CVS.Results: After exposure to 10-fold dilutions of test solutions for 48 hours, HCEC viabilities were 48.5% for 0.5% Timoptol, 80.9% for preservative-free 0.5% timolol maleate, 47.0% for 1% Trusopt, 71.7% for preservative-free 1% dorzolamide, 55.5% for Travatan, 88.5% for Travatan Z, and 52.5% for Xalatan. Exposure to test solutions diluted 100-fold or more resulted in HCEC viabilities > 80%, with the exception of preservative-free 1% dorzolamide, which resulted in a viability of 72.0% at a dilution of 100-fold. Based on CVS, the order of cell viability was Travatan Z ≥ preservative-free timolol maleate = preservative-free dorzolamide > 0.5% Timoptol = 1% Trusopt > Travatan ≥ Xalatan. Assessment of the

  9. Reduction of cytotoxicity of benzalkonium chloride and octenidine by Brilliant Blue G.

    Science.gov (United States)

    Bartok, Melinda; Tandon, Rashmi; Alfaro-Espinoza, Gabriela; Ullrich, Matthias S; Gabel, Detlef

    2015-01-01

    The irritative effects of preservatives found in ophthalmologic solution, or of antiseptics used for skin disinfection is a consistent problem for the patients. The reduction of the toxic effects of these compounds is desired. Brilliant Blue G (BBG) has shown to meet the expected effect in presence of benzalkonium chloride (BAK), a well known preservative in ophthalmic solutions, and octenidine dihydrochloride (Oct), used as antiseptic in skin and wound disinfection. BBG shows a significant protective effect on human corneal epithelial (HCE) cells against BAK and Oct toxicity, increasing the cell survival up to 51 % at the highest BAK or Oct concentration tested, which is 0.01 %, both at 30 min incubation. Although BBG is described as a P2x7 receptor antagonist, other selective P2x7 receptor antagonists, OxATP (adenosine 5'-triphosphate-2',3'-dialdehyde) and DPPH (N'-(3,5-dichloropyridin-4-yl)-3-phenylpropanehydrazide), did not reduce the cytotoxicity of neither BAK nor Oct. Therefore we assume that the protective effect of BBG is not due to its action on the P2x7 receptor. Brilliant Blue R (BBR), a dye similar to BBG, was also tested for protective effect on BAK and Oct toxicity. In presence of BAK no significant protective effect was observed. Instead, with Oct a comparable protective effect was seen with that of BBG. To assure that the bacteriostatic effect is not affected by the combinations of BAK/BBG, Oct/BBG and Oct/BBR, bacterial growth inhibition was analyzed on different Gram-negative and Gram-positive bacteria. All combinations of BAK or Oct with BBG hinder growth of Gram-positive bacteria. The combinations of 0.001 % Oct and BBR above 0.025 % do not hinder the growth of B. subtilis. For Gram-negative bacteria, BBG and BBR reduce, but do not abolish, the antimicrobial effect of BAK nor of Oct. In conclusion, the addition of BBG at bacterial inhibitory concentrations is suggested in the ready-to-use ophthalmic preparations and antiseptic solutions.

  10. Evaluation of Biomarkers of Inflammation in Response to Benzalkonium Chloride on Corneal and Conjunctival Epithelial Cells

    Science.gov (United States)

    Chen, Dongmei; Asbell, Penny A.

    2009-01-01

    Abstract Purpose Most eye drops contain preservatives; benzalkonium chloride (BAK) is most common. Recent data demonstrated BAK adding to toxicity. BAK is degraded into hydrogen peroxide (H2O2), which in even small amounts is known to be an irritant. Increased toxicity should cause localized inflammation with increased elaboration of inflammatory biomarkers. To evaluate the inflammation BAK causes to the ocular surface, enzyme linked immunosorbant assays (ELISAs) were utilized to quantify the levels of inflammatory biomarkers in response to BAK and/or H2O2. Methods Immortalized human conjunctival and corneal epithelial cells were exposed to: BAK (0.001%–0.1%), hydrogen peroxide (H2O2) (0.01%–0.1%), and cell media for 1 h. Cytokine quantification was performed via enzyme-linked immunosorbent assays [ELISAs]). Additional experimentation was performed in which testing solutions were replaced with media after 1 h and the resulting supernatants quantified after 24 h. Results BAK induced significant amounts of interleukin (IL-) 1 and tumor necrosis factor (TNF), but only moderate amounts of C-reactive protein (CRP), IL- 10 and 12, and H2O2. Lower concentrations of BAK induced proportionally less elaboration. Replacing the test solutions with media and providing 23 h for cytokine elaboration significantly increased TNF, but not IL-1. Lipopolysaccharide (LPS) positive controls induced substantial elaboration/release of both IL-1 and TNF as did in increasing the exposure to the full 24 h. Conclusions After 1 h of exposure, BAK increased quantities of all biomarkers. The biomarkers in decreasing order of induction/upregulation were: TNF ≥ IL-1 ≥ IL-12 ≥ IL-10 ≥ CRP. Even low concentrations caused some degree of inflammation. Replacing the testing solution with media and providing 23 h for cytokine elaboration, significantly increased the elaboration/release of TNF, but not IL-1, as compared to the 1-h BAK exposure. Whereas increasing the exposure to the full 24 h

  11. Corneal toxicity secondary to inadvertent use of benzalkonium chloride preserved viscoelastic material in cataract surgery

    Science.gov (United States)

    Eleftheriadis, H; Cheong, M; Sandeman, S; Syam, P P; Brittain, P; Klintworth, G K; Lloyd, A; Liu, C

    2002-01-01

    Aims: To study the long term toxic effects of intraocular benzalkonium chloride (BAC). Methods: 19 patients exposed to intraocular BAC preserved viscoelastic during cataract surgery in February 1999 developed severe striate keratopathy immediately postoperatively. 16 patients, including two who underwent penetrating keratoplasty, were studied in the period April to June 2000. Ocular symptoms, visual acuity, biomicroscopy, intraocular pressure, dilated funduscopy, specular endothelial microscopy, and corneal pachymetry findings were recorded. The corneal and iris specimens of the two patients who underwent keratoplasty were studied by light, transmission, and scanning electron microscopy. Results: Six males and 10 females, aged 64–98 years, were studied 14–16 months postoperatively. All patients were symptomatic. 12 patients had best corrected visual acuity of 6/12 or better and four patients of between 6/18 and 6/60. Five patients had corneal epithelial oedema and 11 had Descemet's membrane folds. The central corneal thickness, 620 (SD 71) μm, in affected eyes was significantly higher (p<0.005, two tailed paired t test) than that of the contralateral eyes, 563 (SD 48) μm. The endothelial cell density was significantly lower (p<0.0001, two tailed paired t test) in affected eyes: 830 (SD 280) cells/mm2v 2017 (SD 446) cells/mm2. The mean average cell area was significantly higher in the BAC treated eyes: 1317 (SD 385) μm2v 521 (SD 132) μm2. There was no significant difference in the coefficient of variation of cell size between the two eyes (p=0.3, two tailed paired t test). Two corneal specimens displayed morphological features of bullous keratopathy and other non-specific abnormalities. Extracellular melanosomes were present in a portion of the iris of one case. Conclusion: BAC is toxic to the corneal endothelium when used intraocularly, leading to severe striate keratopathy. This cleared in most cases but left varying degrees of residual stromal thickening

  12. Hyperosmolarity potentiates toxic effects of benzalkonium chloride on conjunctival epithelial cells in vitro

    Science.gov (United States)

    Godefroy, David; Riancho, Luisa; Rostène, William; Baudouin, Christophe; Brignole-Baudouin, Françoise

    2012-01-01

    Purpose Benzalkonium chloride (BAK), the most commonly used preservative in eye drops, is known to induce ocular irritation symptoms and dry eye in long-term treated patients and animal models. As tear film hyperosmolarity is diagnostic of some types of dry eye disease, we determined in vitro on conjunctival epithelial cells the cytoxicity of BAK in hyperosmolar conditions through cell viability, apoptosis, and oxidative stress assays. Methods The Wong Kilbourne derivative of Chang conjunctival epithelial cells were cultured for 24 h or 48 h either in NaCl-induced hyperosmolar conditions (400–425–500 mOsM), in low concentrations of BAK (10−4%, 3.10−4%, and 5.10−4%), or in combination of both. We investigated cell viability through lysosomal integrity evaluation, cell death (cell membrane permeability and chromatin condensation), and oxidative stress (reactive oxygen species, superoxide anion) using spectrofluorimetry. Immunohistochemistry was performed for cytoskeleton shrinkage (phalloidin staining), mitochondrial permeability transition pore (cytochrome c release), the apoptosis effector active caspase-3, and the caspase-independent apoptosis factor AIF. We also observed early effects induced by the experimental conditions on the conjunctival cell layers using phase contrast imaging of live cells. Results As compared to standard culture solutions, hyperosmolar stress potentiated BAK cytotoxicity on conjunctival cells through the induction of oxidative stress; reduction of cell viability; cell membrane permeability increase; cell shrinkage with cell blebbing, as shown in phase contrast imaging of live cells; and chromatin condensation. Like BAK, but to a much lesser extent, hyperosmolarity increased cell death in a concentration-dependent manner through a caspase-dependent apoptosis characterized by a release of cytochrome c in the cytoplasm from mitochondria and the activation of caspase-3. Moreover, the caspase-independent apoptosis factor AIF was

  13. Tn6188 - a novel transposon in Listeria monocytogenes responsible for tolerance to benzalkonium chloride.

    Science.gov (United States)

    Müller, Anneliese; Rychli, Kathrin; 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 ΔqacH 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

  14. The influence of subminimal inhibitory concentrations of benzalkonium chloride on biofilm formation by Listeria monocytogenes.

    Science.gov (United States)

    Ortiz, Sagrario; López, Victoria; Martínez-Suárez, Joaquín V

    2014-10-17

    Disinfectants, such as benzalkonium chloride (BAC), are commonly used to control Listeria monocytogenes and other pathogens in food processing plants. Prior studies have demonstrated that the resistance to BAC of L. monocytogenes was associated with the prolonged survival of three strains of molecular serotype 1/2a in an Iberian pork processing plant. Because survival in such environments is related to biofilm formation, we hypothesised that the influence of BAC on the biofilm formation potential of L. monocytogenes might differ between BAC-resistant strains (BAC-R, MIC≥10mg/L) and BAC-sensitive strains (BAC-S, MIC≤2.5mg/L). To evaluate this possibility, three BAC-R strains and eight BAC-S strains, which represented all of the molecular serotype 1/2a strains detected in the sampled plant, were compared. Biofilm production was measured using the crystal violet staining method in 96-well microtitre plates. The BAC-R strains produced significantly (p<0.05) less biofilm than the BAC-S in the absence of BAC, independent of the rate of planktonic growth. In contrast, when the biofilm values were measured in the presence of BAC, one BAC-R strain (S10-1) was able to form biofilm at 5mg/L of BAC, which prevented biofilm formation among the rest of the strains. A genetic determinant of BAC resistance recently described in L. monocytogenes (Tn6188) was detected in S10-1. When a BAC-S strain and its spontaneous mutant BAC-R derivative were compared, resistance to BAC led to biofilm formation at 5mg/L of BAC and to a significant (p<0.05) stimulation of biofilm formation at 1.25mg/L of BAC, which significantly (p<0.05) reduced the biofilm level in the parent BAC-S strain. Our results suggest that the effect of subminimal inhibitory concentrations of BAC on biofilm production by L. monocytogenes might differ between strains with different MICs and even between resistant strains with similar MICs but different genetic determinants of BAC resistance. For BAC-R strains similar

  15. Toxicity of antiglaucoma drugs with and without benzalkonium chloride to cultured human corneal endothelial cells

    Science.gov (United States)

    Ayaki, Masahiko; Iwasawa, Atsuo; Inoue, Yoichi

    2010-01-01

    Purpose The toxicity of antiglaucoma medications to ocular surface cells has been evaluated extensively; however, the toxicity to corneal endothelial cells (CECs) remains elusive. Our aim is to evaluate the toxicity of antiglaucoma medications to CECs using an in vitro toxicity assay. Methods Primary cultures of human (H) CECs derived from eye bank specimens were established. Following exposure of HCECs to test solutions for 10, 30, or 60 minutes, or 48 hours, we measured cell viability using a WST-1 assay. Test solutions were diluted in culture media and included 0.5% Timoptol®, preservative-free 0.5% timolol maleate, 1% Trusopt®, preservative-free 1% dorzolamide, Travatan®, Travatan Z®, Xalatan®, and benzalkonium chloride (BAK). To assess cell viability, the value of the test culture well after treatment was expressed as a percentage of that of the control well. Toxicity of each solution was compared using the cell viability score (CVS). Results After exposure to 10-fold dilutions of test solutions for 48 hours, HCEC viabilities were 48.5% for 0.5% Timoptol, 80.9% for preservative-free 0.5% timolol maleate, 47.0% for 1% Trusopt, 71.7% for preservative-free 1% dorzolamide, 55.5% for Travatan, 88.5% for Travatan Z, and 52.5% for Xalatan. Exposure to test solutions diluted 100-fold or more resulted in HCEC viabilities >80%, with the exception of preservative-free 1% dorzolamide, which resulted in a viability of 72.0% at a dilution of 100-fold. Based on CVS, the order of cell viability was Travatan Z ≥ preservative-free timolol maleate = preservative-free dorzolamide > 0.5% Timoptol = 1% Trusopt > Travatan ≥ Xalatan. Assessment of the combined effect of drug and BAK revealed that latanoprost reduced the toxicity of BAK. Conclusion Antiglaucoma eye drops produced HCEC toxicity that appeared to depend on the presence of BAK. Because dilution of the antiglaucoma solutions resulted in markedly lower HCEC toxicity, HCEC damage due to antiglaucoma medication may

  16. Enhanced microbial biomass assay using mutant luciferase resistant to benzalkonium chloride.

    Science.gov (United States)

    Hattori, Noriaki; Sakakibara, Tatsuya; Kajiyama, Naoki; Igarashi, Toshinori; Maeda, Masako; Murakami, Seiji

    2003-08-15

    In a biomass assay based on adenosine 5(')-triphosphate (ATP) bioluminescence, extracellular ATP is removed; then intracellular ATP is extracted from the microorganism by an ATP extractant and subsequently reacted with luciferase. To provide a highly sensitive assay, the concentration of benzalkonium chloride (BAC) in the ATP extractant was optimized by using a mutant luciferase resistant to BAC. The use of 0.2% BAC, which was acceptable for the luciferase, simultaneously achieved the maximum extraction of intracellular ATP from microorganisms and the inactivation of the ATP-eliminating enzymes for removal of extracellular ATP. The detection limit (blank+3 SD) for ATP was 1.8x10(-14)M (1.8x10(-18)mol/assay) in the presence of the ATP extractant with coefficients of variation of 0.7 to 6.3%. The reagent system coupled with the ATP-eliminating enzymes allowed for the detection of 93 colony-forming units (CFU)/ml of Escherichia coli ATCC 25922, 170CFU/ml of Pseudomonas aeruginosa ATCC 27853, 170CFU/ml of Proteus mirabilis ATCC 29906, 68CFU/ml of Staphylococcus aureus ATCC 25923, and 7.7CFU/ml of Bacillus subtilis ATCC 6051. The yeast cell of Saccharomyces cerevisiae IFO 10217 could be detected at 1CFU/ml. With 54 kinds of microorganisms, the average ATP extraction efficiency compared to the trichloroacetic acid extraction method was 81.0% in 24 strains among gram-negative bacteria, 99.4% in 13 strains among gram-positive bacteria, and 97.0% in 17 strains among yeast. The ATP contents of the gram-negative bacteria, gram-positive bacteria, and yeasts ranged from 0.40 to 2.70x10(-18)mol/CFU (mean=1.5x10(-18)mol/CFU), from 0.41 to 16.7x10(-18)mol/CFU (mean=5.5x10(-18)mol/CFU), and from 0.714 to 54.6x10(-16)mol/CFU (mean=8.00x10(-16)mol/CFU), respectively.

  17. Effects of Benzalkonium Chloride, Proxel LV, P3 Hypochloran, Triton X-100 and DOWFAX 63N10 on anaerobic digestion processes

    DEFF Research Database (Denmark)

    Flores, German Antonio Enriquez; Fotidis, Ioannis; Karakashev, Dimitar Borisov

    2015-01-01

    In this study, the individual and synergistic toxicity of the following xenobiotics: Benzalkonium Chloride (BKC), Proxel LV (PRX), P3 Hypochloran (HPC), Triton X-100 (TRX), and DOWFAX 63N10 (DWF), on anaerobic digestion (AD) process, was assessed. The experiments were performed in batch and conti...

  18. Susceptibility of different bacterial species isolated from food animals to copper sulphate, zinc chloride and antimicrobial substances used for disinfection

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Hasman, Henrik

    2004-01-01

    that Danish bacterial isolates from livestock so far have not or have only to a limited degree developed resistance to antimicrobial compounds commonly used for disinfection. Acquired copper resistance was only found in enterococci. There were large differences in the intrinsic susceptibility of the different......A total of 569 different bacterial isolates (156 Salmonella, 202 E. coli, 43 S. aureus, 38 S. hyicus, 52 E. faecalis, 78 E faecium) were tested for susceptibility to copper sulphate, benzalkonium chloride, hydrogen peroxide and chlorhexidine using MIC determinations. A total of 442 isolates were...... of susceptibilities to the different antimicrobial agents. Large variations were observed in the susceptibility of the different bacterial species to the different compounds. Staphylococci were in general very susceptible to all antimicrobial compounds tested. The Salmonella isolates were in general less susceptible...

  19. Effect of benzalkonium chloride-free latanoprost ophthalmic solution on ocular surface in patients with glaucoma

    Directory of Open Access Journals (Sweden)

    Walimbe T

    2016-05-01

    Full Text Available Tejaswini Walimbe,1 Vidya Chelerkar,2 Purvi Bhagat,3 Abhijeet Joshi,4 Atul Raut4 1Walimbe Eye Clinic, 2PBMA’s H.V. Desai Eye Hospital, Pune, 3Glaucoma Clinic, M and J Western Regional Institute of Ophthalmology, Civil Hospital, Ahmedabad, 4Clinical Research Department, Sun Pharma Advanced Research Company Ltd., Mumbai, India Introduction: Benzalkonium chloride (BAK, included as a preservative in many topical treatments for glaucoma, induces significant toxicity and alters tear breakup time (TBUT. BAK-containing latanoprost, an ester prodrug of prostaglandin F2a, can cause ocular adverse events (AEs associated with BAK. The purpose of this study was to evaluate the efficacy and safety of BAK-free latanoprost. Patients and methods: A prospective, open-label, single-arm, multicenter, 8-week study in patients with primary open-angle glaucoma or ocular hypertension taking BAK-containing latanoprost for ≥12 months was performed. Patients were switched to BAK-free latanoprost ophthalmic solution 0.005% administered once daily, and eyes were assessed after 28 and 56 days. Primary efficacy and safety variables were TBUT and treatment-emergent AEs, respectively. Results: At day 56, 40 eyes were evaluable. Mean TBUT increased significantly from baseline (3.67±1.60 seconds to 5.03±2.64 and 6.06±3.39 seconds after 28 and 56 days of treatment with BAK-free latanoprost (P<0.0001. Ocular Surface Disease Index© (OSDI© score also decreased significantly to 12.06±13.40 and 7.06±10.75 at 28 and 56 days, respectively, versus baseline (18.09±18.61, P<0.0001. In addition, inferior corneal staining score decreased significantly to 0.53 from baseline (0.85, P=0.0033. A reduction in conjunctival hyperemia and intraocular pressure was observed at both time points. No treatment-related serious AEs were evident and 12 (26.08% treatment-emergent AEs occurred in seven patients, with eye pain and irritation being the most frequent. No clinically significant changes

  20. Inactivation of human norovirus surrogates by benzalkonium chloride, potassium peroxymonosulfate, tannic acid, and gallic acid.

    Science.gov (United States)

    Su, Xiaowei; D'Souza, Doris H

    2012-09-01

    Novel methods to effectively disinfect contact surfaces and prevent human norovirus transmission are essential. The effect of benzalkonium chloride (BAC), potassium peroxymonosulfate (KPMS), tannic acid (TA), and gallic acid (GA) on enteric virus surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), and bacteriophage MS2 was studied. Viruses at high (∼7 log₁₀ PFU/mL) or low (∼5 log₁₀ PFU/mL) titers were mixed with equal volumes of BAC (0.2, 0.5, and 1 mg/mL), KPMS (5, 10, and 20 mg/mL), TA (0.02 and 0.2 mg/mL), GA (0.2, 0.4, and 0.8 mg/mL), or water and incubated for 2 h at room temperature. Viral infectivity after triplicate treatments was evaluated using plaque assays in duplicate. Low titers of FCV-F9 and MNV-1 were completely reduced, while low-titer MS2 was reduced by 1.7-1.8 log₁₀ PFU/mL with BAC at all three concentrations. High-titer FCV-F9 was reduced by 2.87, 3.08, and 3.25 log₁₀ PFU/mL, and high-titer MNV-1 was reduced by 1.55, 2.32, and 2.75 log₁₀ PFU/mL with BAC at 0.1, 0.25, and 0.5 mg/mL, respectively. High-titer MS2 was reduced by ∼2 log₁₀ PFU/mL with BAC at all three concentrations. KPMS at all three concentrations reduced high and low titers of FCV-F9 and MS2 and low-titer MNV-1 to undetectable levels, while high-titer MNV-1 was reduced by 0.92 and 3.44 log₁₀ PFU/mL with KMPS at 2.5 and 5 mg/mL, respectively. TA at 0.2 mg/mL only reduced high-titer FCV-F9 by 0.98 log₁₀ PFU/mL and low-titer FCV-F9 by 1.95 log₁₀ PFU/mL. GA at 0.1, 0.2, and 0.4 mg/mL reduced low-titer FCV-F9 by 2.50, 2.36, and 0.86 log₁₀ PFU/mL, respectively with negligible effects against high-titer FCV-F9. BAC and KPMS show promise to be used as broad-spectrum contact surface disinfectants for prevention of noroviral surrogate contamination.

  1. Benzalkonium chloride and sulfamethoxazole adsorption onto natural clinoptilolite: effect of time, ionic strength, pH and temperature.

    Science.gov (United States)

    Farías, Tania; de Ménorval, Louis Charles; Zajac, Jerzy; Rivera, Aramis

    2011-11-15

    The influence of different physical factors on the adsorption of the cationic surfactant benzalkonium chloride (BC) and the model drug sulfamethoxazole by a purified natural clinoptilolite (NZ) has been studied in order to employ zeolite-surfactant-drug composites as drug deliverer. It has been demonstrated that the adsorption of BC and sulfamethoxazole onto NZ depends of the time, the temperature, the ionic strength and the pH of the aqueous medium. The optimal conditions for the preparation of the zeolite-surfactant and zeolite-surfactant-drug composite materials are established. The results of the composite characterization support the presence of BC and sulfamethoxazole, as well as the structural stability of NZ during the treatments performed. The release experiments in acid medium demonstrate that the adsorption of sulfamethoxazole is reversible. It is also confirmed that the drug release profile corresponds to a diffusion or zero-order mechanism as a function of the compression pressure.

  2. Benzalkonium chloride exposure in cats: a retrospective analysis of 245 cases reported to the Veterinary Poisons Information Service (VPIS).

    Science.gov (United States)

    Bates, N; Edwards, N

    2015-02-28

    Benzalkonium chloride is commonly found in household products. This retrospective study examined 245 cases of feline exposure to benzalkonium chloride-containing products reported to the Veterinary Poisons Information Service (VPIS). A single route of exposure was reported in 188 cats (ingestion 126, skin 58, buccal 4); 57 cats had multiple routes. The common products involved were household antibacterial cleaners (43.6 per cent), household disinfectants (22.3 per cent) and patio cleaners (17.5 per cent). The most common signs were hypersalivation/drooling (53.9 per cent), tongue ulceration (40.4 per cent), hyperthermia (40.4 per cent) and oral ulceration (22.9 per cent). The mean time recorded for onset of the first clinical sign was 6.4 hours (range five minutes to 48 hours, median 4.5 hours, n=60), however, the VPIS was not contacted until 14.0 ± 13.2 hours after exposure (n=120). This figure also reflects the time of presentation. The most common treatments given were antibiotics (82.0 per cent), fluids (50.2 per cent), analgesia (45.3 per cent), gastroprotectants (31.0 per cent), dermal decontamination (24.1 per cent) and steroids (22.7 per cent). 13 cats (5.3 per cent) received syringe or nasogastric feeding. Of 245 cats, 12 (4.9 per cent) remained asymptomatic, 230 (93.9 per cent) recovered and three died (1.2 per cent). The time to recovery ranged from 1 to 360 hours (n=67) with a mean of 100.4 ± 82.0 hours (4.2 ± 3.4 days, median 72 hours).

  3. Preservative toxicity in glaucoma medication: clinical evaluation of benzalkonium chloride-free 0.5% timolol eye drops

    Directory of Open Access Journals (Sweden)

    Rosin LM

    2013-10-01

    Full Text Available Lauren M Rosin,1 Nicholas P Bell1,2 1Ruiz Department of Ophthalmology and Visual Science, The University of Texas Medical School at Houston, 2Robert Cizik Eye Clinic, Houston, TX, USA Abstract: Timolol (generic name is a frequently used medication for the control of glaucoma. Benzalkonium chloride (BAK is a commonly used preservative in ophthalmic solutions with a broad range of antimicrobial activity; however, this nonspecificity can result in toxicity. Adverse effects attributed to BAK, including conjunctival inflammation and fibrosis, tear film instability, corneal cytotoxicity, anterior chamber inflammation, trabecular meshwork cell apoptosis, cataract development, macular edema, and even systemic effects, have been well documented. These effects can lead to ocular discomfort, poor intraocular pressure control, glaucoma surgery failure, and decreased patient compliance. BAK use in topical medications has decreased recently as newer and less toxic preservatives have become available. Yet these preservatives still exert some toxic effects, especially in patients with chronic eye disease who use multiple drops over extended periods of time. Thus, attempts to reduce overall preservative loads for patients are important, whether it be decreasing the amount of preservative, decreasing the total number of drops patients use, or eliminating preservatives entirely. A preservative-free formulation of timolol, TIMOPTIC® in OCUDOSE®, is available in unit-dose vials. Preservative-free unit-dose vials minimize toxic adverse effects and are a good option for patients with ocular surface disease, on long-term multidrop therapy, or who simply do not tolerate the effects of preservatives due to discomfort. Keywords: glaucoma, ocular toxicity, benzalkonium chloride, preservative-free timolol

  4. In Vitro and in Vivo Experimental Studies on Trabecular Meshwork Degeneration Induced by Benzalkonium Chloride (An American Ophthalmological Society Thesis)

    Science.gov (United States)

    Baudouin, Christophe; Denoyer, Alexandre; Desbenoit, Nicolas; Hamm, Gregory; Grise, Alice

    2012-01-01

    Purpose: Long-term antiglaucomatous drug administration may cause irritation, dry eye, allergy, subconjunctival fibrosis, or increased risk of glaucoma surgery failure, potentially due to the preservative benzalkonium chloride (BAK), whose toxic, proinflammatory, and detergent effects have extensively been shown experimentally. We hypothesize that BAK also influences trabecular meshwork (TM) degeneration. Methods: Trabecular specimens were examined using immunohistology and reverse transcriptase–polymerase chain reaction. A trabecular cell line was stimulated by BAK and examined for apoptosis, oxidative stress, fractalkine and SDF-1 expression, and modulation of their receptors. An experimental model was developed with BAK subconjunctival injections to induce TM degeneration. Mass spectrometry (MS) imaging assessed BAK penetration after repeated instillations in rabbit eyes. Results: Trabecular specimens showed extremely low densities of trabecular cells and presence of cells expressing fractalkine and fractalkine receptor and their respective mRNAs. Benzalkonium in vitro induced apoptosis, oxidative stress, and fractalkine expression and inhibited the protective chemokine SDF-1 and Bcl2, also inducing a sustained intraocular pressure (IOP) increase, with dramatic apoptosis of trabecular cells and reduction of aqueous outflow. MS imaging showed that BAK could access the TM at measurable levels after repeated instillations. Conclusion: BAK enhances all characteristics of TM degeneration typical of glaucoma—trabecular apoptosis, oxidative stress, induction of inflammatory chemokines—and causes degeneration in acute experimental conditions, potentially mimicking long-term accumulation. BAK was also shown to access the TM after repeated instillations. These findings support the hypothesis that antiglaucoma medications, through toxicity of their preservative, may cause further long-term trabecular degeneration and therefore enhance outflow resistance, reducing the

  5. 双氯芬酸钠滴眼液中苯扎氯铵的测定%Determination of benzalkonium chloride in diclofenac sodium eye drops

    Institute of Scientific and Technical Information of China (English)

    李玮玲

    2013-01-01

    Objective To develop a method to determine benzalkonium chloride in diclofenac sodium eye drops. Methods Separation was performed on a CNW column (150 mmX4.6 mm, 5 urn). The mobile phase consisted of acetonitrile: 5 mmol · L-1 ammonium acetate-1% triethylamine (adjusting pH to 5.0 ± 0.5 by acetic acid) = 65 : 35 (v/v). The UV detection was 214 nm. Results Benzalkonium chloride had a good linearity at 12.50 - 125.00 μg · mL-1, the average recovery of benzalkonium chloride was 99.0% and the RSD was 1.3%. Conclusion The method is simple, rapid and sensitive, and it could be applied to determine benzalkonium chloride in diclofenac sodium eye drops.%目的 采用HPLC双氯芬酸钠滴眼液中苯扎氯铵的含量.方法 乙腈-5mmol·L-1醋酸铵溶液(含1%三乙胺,用冰醋酸调节pH值至5.0±0.5)(65:35)为流动相,CNW色谱柱(150 mm×4.6 mm,5 μm),检测波长为214 nm.结果 苯扎氯铵的测定在12.50~125.00 μg·mL-1与峰面积线性关系良好,苯扎氯铵的平均回收率为99.0%,RSD为1.3%.结论 方法简单、灵敏度高,可用于双氯芬酸钠滴眼液中苯扎氯铵的测定.

  6. Development of Calcitonin Salmon Nasal Spray: similarity of peptide formulated in chlorobutanol compared to benzalkonium chloride as preservative.

    Science.gov (United States)

    Costantino, Henry R; Culley, Heather; Chen, Lishan; Morris, Daniel; Houston, Michael; Roth, Sharin; Phoenix, Mary Jo; Foerder, Chuck; Philo, John S; Arakawa, Tsutomu; Eidenschink, Lisa; Andersen, Niels H; Brandt, Gordon; Quay, Steven C

    2009-10-01

    The similarity of an intranasal salmon calcitonin (sCT) employing chlorobutanol as preservative (Calcitonin Salmon Nasal Spray) was compared to the reference listed drug (RLD) employing benzalkonium chloride as preservative (Miacalcin Nasal Spray). Various orthogonal methods assessed peptide structuring, dynamics, and aggregation state. Mass spectrometry, amino acid analysis, and N-terminal sequencing all demonstrated similarity in primary structure. Near- and far-UV circular dichroism (CD) data supported similarity in secondary and tertiary sCT structure. Nuclear magnetic resonance studies further supported similarity of three-dimensional structure and molecular dynamics of the peptide. Other methods, such as sedimentation velocity and size exclusion chromatography, demonstrated similarity in peptide aggregation state. These latter methods, in addition to reversed phase chromatography, were also employed for monitoring stability under forced degradation, and at the end of recommended shelf storage and patient use conditions. In all cases and for all methodologies employed, similarity to the RLD was observed with respect to extent of aggregation and other degradation processes. Finally, ELISA and bioassay data demonstrated similarity in biological properties. These investigations comprehensively demonstrate physicochemical similarity of Calcitonin Salmon Nasal Spray and the RLD, and should prove a useful illustration to pharmaceutical scientists developing alternative and/or generic peptide or protein products.

  7. Adsorption of the disinfectant benzalkonium chloride on montmorillonite. Synergistic effect in mixture of molecules with different chain lengths.

    Science.gov (United States)

    Zanini, Graciela P; Ovesen, Rikke Gleerup; Hansen, H C B; Strobel, Bjarne W

    2013-10-15

    The biocide benzalkonium chloride (BAC) is a mix of cationic alkylbenzyldimethylammonium surfactants having different alkyl chain lengths. A comparative study of adsorption on the phyllosilicate clay montmorillonite of two of these surfactants, with alkyl chains having respectively 12 C atoms (BAC-12) and 14 C atoms (BAC-14), and a mixture of both surfactants is presented in this work. Adsorption isotherms were performed for individual surfactants and for a 1:1 mixture BAC-12+BAC-14. The adsorption was investigated in an ample concentration range that covers almost seven orders of magnitude in concentrations (from 1 nM to 10 mM), range that includes environmentally relevant concentrations. Quantification of BAC was performed by HPLC-UV and LC-MS and the results were completed with powder X-Ray diffraction. The adsorption of both surfactants leads to adsorption isotherms with two well differentiated steps. The first step corresponds almost exclusively to a cation exchange process, and the binding constant is very similar for both surfactants. The second step of the isotherms is observed at higher concentrations and adsorption is mainly driven by lateral interactions between surfactant molecules. The binding constant of this step is larger for BAC-14 than for BAC-12. Adsorption from a BAC-12+BAC-14 mixture shows a synergistic behaviour, possibly due to a better packing arrangement in the interlayer. Calculations show that in natural systems silicate clays are major sorbents of BAC at low concentrations whereas binding to humic acid is predominant at high concentrations.

  8. Toxicity and genotoxicity of the quaternary ammonium compound benzalkonium chloride (BAC) using Daphnia magna and Ceriodaphnia dubia as model systems.

    Science.gov (United States)

    Lavorgna, Margherita; Russo, Chiara; D'Abrosca, Brigida; Parrella, Alfredo; Isidori, Marina

    2016-03-01

    The toxicity and genotoxicity of the cationic surfactant benzalkonium chloride (BAC) were studied using Daphnia magna and Ceriodaphnia dubia as model systems. Acute and chronic toxicity testing were performed according to the international standard guidelines and the genotoxicity was detected through the comet assay on cells from whole organisms in vivo exposed. Acute effects occurred at concentrations in the order of tens of μg/L in D. magna and hundreds of μg/L in C. dubia. Chronic effects were found at one order of magnitude less than short-term effects maintaining the same difference in sensitivity between D. magna and C. dubia. BAC induced relevant DNA damage, in both cladocerans; the lowest adverse effect levels were 0.4 and 4 ng/L for D. magna and C. dubia, respectively. As these effective concentrations are far lower than BAC occurrence in surface waters (units of μg/L) a concerning environmental risk cannot be excluded. The findings of this study showed that D. magna and C. dubia, could be used as model organisms to detect acute and chronic toxicity as well as genotoxicity at the whole organism level.

  9. Genoprotective effect of hyaluronic acid against benzalkonium chloride-induced DNA damage in human corneal epithelial cells

    Science.gov (United States)

    Wu, Han; Zhang, Huina; Wang, Changjun; Wu, Yihua; Xie, Jiajun; Jin, Xiuming; Yang, Jun

    2011-01-01

    Purpose The aim of this study was to investigate hyaluronic acid (HA) protection on cultured human corneal epithelial cells (HCEs) against benzalkonium chloride (BAC)-induced DNA damage and intracellular reactive oxygen species (ROS) increase. Methods Cells were incubated with different concentrations of BAC with or without the presence of 0.2% HA for 30 min. DNA damage to HCEs was examined by alkaline comet assay and by immunofluorescence microscopic detection of the phosphorylated form of histone variant H2AX (γH2AX) foci. ROS production was assessed by the fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). Cell apoptosis was determined with annexin V staining by flow cytometry. Results HA significantly reduced BAC-induced DNA damage as indicated by the tail length (TL) and tail moment (TM) of alkaline comet assay and by γH2AX foci formation, respectively. Moreover, HA significantly decreased BAC-induced ROS increase and cell apoptosis. However, exposure to HA alone did not produce any significant change in DNA damage, ROS generation, or cell apoptosis. Conclusions BAC could induce DNA damage and cell apoptosis in HCEs, probably through increasing oxidative stress. Furthermore, HA was an effective protective agent that had antioxidant properties and could decrease DNA damage and cell apoptosis induced by BAC. PMID:22219631

  10. Decrease in Corneal Damage due to Benzalkonium Chloride by the Addition of Mannitol into Timolol Maleate Eye Drops.

    Science.gov (United States)

    Nagai, Noriaki; Yoshioka, Chiaki; Tanino, Tadatoshi; Ito, Yoshimasa; Okamoto, Norio; Shimomura, Yoshikazu

    2015-01-01

    We investigated the protective effects of mannitol on corneal damage caused by benzalkonium chloride (BAC), which is used as a preservative in commercially available timolol maleate eye drops, using rat debrided corneal epithelium and a human cornea epithelial cell line (HCE-T). Corneal wounds were monitored using a fundus camera TRC-50X equipped with a digital camera; eye drops were instilled into rat eyes five times a day after corneal epithelial abrasion. The viability of HCE-T cells was calculated by TetraColor One; and Escherichia coli (ATCC 8739) were used to measure antimicrobial activity. The reducing effects on transcorneal penetration and intraocular pressure (IOP) of the eye drops were determined using rabbits. The corneal wound healing rate and rate constant (kH), as well as cell viability, were higher following treatment with 0.005% BAC solution containing 0.5% mannitol than in the case BAC solution alone; the antimicrobial activity was approximately the same for BAC solutions with and without mannitol. In addition, the kH for rat eyes instilled with commercially available timolol maleate eye drops containing 0.5% mannitol was significantly higher than that for eyes instilled with timolol maleate eye drops without mannitol, and the addition of mannitol did not affect the corneal penetration or IOP reducing effect of the timolol maleate eye drops. A preservative system comprising BAC and mannitol may provide effective therapy for glaucoma patients requiring long-term treatment with anti-glaucoma agents.

  11. Transcorneal permeation of diclofenac as a function of temperature from film formulation in presence of triethanolamine and benzalkonium chloride.

    Science.gov (United States)

    Mohapatra, Rajaram; Senapati, Sibananda; Sahoo, Chinmaya; Mallick, Subrata

    2014-11-01

    The objective of this report was to evaluate the transcorneal permeation of diclofenac potassium (DCP) as a function of temperature from hydroxypropyl methylcellulose (HPMC) matrix film containing triethanolamine (TEM) as plasticizer and benzalkonium chloride (BKC) as preservative. Activation energy (Ea), enthalpy (ΔH), entropy (ΔS) and free energy (ΔG) of permeation, diffusion and partition were evaluated to understand the underlying mechanism of permeation. Permeation improved with the presence of both the plasticizer and preservative compared to preservative alone. Further, increased amount of TEM in the film increased drug transport across the cornea. Decreased Ea value of the film supported the fact. Rise of temperature from 26 to 30, 34 and 40 °C increased permeation in all the films. Ocular residence of the film in vivo in the rabbit revealed that the film swelled by pronounced lachrymal fluid uptake and traces of hydrogel remained still at the end of 6 h of application. Absence of characteristic exothermic peak of the drug in the thermogram of film formulations indicated the molecular dispersion of drug in polymer matrix. Scanning electron microscopy indicated that the drug crystal size decreased with increasing concentration of TEM in presence of BKC due to effective wetting of drug particles by the polymer.

  12. Benzalkonium chloride (BAK induces apoptosis or necrosis, but has no major influence on the cell cycle of Jurkat cells

    Directory of Open Access Journals (Sweden)

    Piotr Pozarowski

    2011-07-01

    Full Text Available Benzalkonium chloride (BAK is a cationic detergent with a very slow turnover. Because of its strong antibacterial activities, BAK is widely used especially in dentistry and ophthalmology. It is the most commonly used preservative in topical ophthalmic medications. Due to chronicity and widespread use of such treatments, BAK’s side effects are of great importance. BAK toxicity for adherent cells, probably related to its pro-oxidative activities, is time- and dose-dependent. Although lymphocytes often infiltrate superficial eye tissues, the BAK influence on them is yet to be established. The aim of this study was to check BAK cytotoxicity on T lymphocytic Jurkat line cells and to verify the suggestion that BAK can induce G2M cell blocks. A dose- and time-dependent cytotoxic effect of BAK on lymphoid cells in relatively low concentrations was shown in this study. In lower concentrations, it shows a moderate apoptotic and minimal antiproliferative effect on Jurkat cells, while in higher concentrations it shows a rapid necrotic effect. No G2M cell blocks were observed. Our findings could suggest lymphoid dysfunction during intensive, prolonged topical BAK treatment, even at dosages relatively non-toxic to epithelial eye cells. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 225–230

  13. Mechanism and toxicity research of benzalkonium chloride oxidation in aqueous solution by H2O2/Fe(2+) process.

    Science.gov (United States)

    Zhang, Qian; Xia, Yu-Feng; Hong, Jun-Ming

    2016-09-01

    As widely used disinfectants, the pollution caused by benzalkonium chloride (BAC) has attracted a lot of attention in recent years. Since it is not suitable for biodegradation, BAC was degraded firstly by Fenton advanced oxidation technologies (AOTs) in this research to enhance the biodegradability of the pollutions. The result revealed that the optimal molar ratio of H2O2/Fe(2+) for BAC degradation was 10:1, and the COD removal rate was 32 %. To clarify the pathway of degradation, the technique of GC-MS was implemented herein to identify intermediates and the toxicity of those BAC intermediates were also novelty tested through microbial fuel cells (MFC). The findings indicated that ten transformation products including benzyl dimethyl amine and dodecane were formed during the H2O2/Fe(2+) processes, which means the degradation pathway of BAC was initiated both on the hydrophobic (alkyl chain) and hydrophilic (benzyl and ammonium moiety) region of the surfactant. The toxicity of BAC before and after treated by Fenton process was monitored through MFC system. The electricity generation was improved 337 % after BAC was treated by H2O2/Fe(2+) oxidation processes which indicated that the toxicity of those intermediates were much lower than BAC. The mechanism and toxicity research in this paper could provide the in-depth understanding to the pathway of BAC degradation and proved the possibility of AOTs for the pretreatment of a biodegradation process.

  14. Meta analysis about the efficacy and safety of anti-ocular hypertension eye drops without benzalkonium chloride

    Institute of Scientific and Technical Information of China (English)

    Yan-Qing Wang; Xin Wang; Ping Liu

    2013-01-01

    Objective:To explore the safety and efficacy of eye drops without benzalkonium chloride(BAK) in treating glaucoma and ocular hypertension.Methods:The clinical case-control literatures about eye drops withoutBAK treating glaucoma and ocular hypertension were retrieved in PubMed,EMBASE,Cochrane andChineseBiological andMedical database.Meta5.0 software was used to analyze the literatures.Results:Five clinicalcontrol studies were included.The results indicated both eye drops could lower the intraocular pressure, and the intraocular pressure-lowering difference between two eye drops was0.07 mmHg(95%CI:0.04,0.19)(P>0.05).Two adverse reactions occurred more were conjunctival injection(10.78%) and allergic conjunctivitis (4.78%).The odd ratio of two eye drops occurring conjunctival injection and allergic conjunctivitis was0.67(95%CI,0.25,1.10) and0.82(95%CI,0.09,1.54), respectively(P<0.05) in fixed effect model.Conclusions:There is no difference between the eye drops with or withoutBAK in lowering intraocular pressure, but the latter is of higher safety.In consideration of the relatively small sample size of this research, more high-quality clinical research contrasts are needed as evidence.

  15. Suppression of c-Kit signaling induces adult neurogenesis in the mouse intestine after myenteric plexus ablation with benzalkonium chloride.

    Science.gov (United States)

    Tamada, Hiromi; Kiyama, Hiroshi

    2016-08-30

    Adult neurogenesis rarely occurs in the enteric nervous system (ENS). In this study, we demonstrated that, after intestinal myenteric plexus (MP) ablation with benzalkonium chloride (BAC), adult neurogenesis in the ENS was significantly induced in c-kit loss-of-function mutant mice (W/W(v)). Almost all neurons and fibers in the MP disappeared after BAC treatment. However, 1 week after ablation, substantial penetration of nerve fibers from the non-damaged area was observed in the MP, longitudinal muscle and subserosal layers in both wildtype and W/W(v) mice. Two weeks after BAC treatment, in addition to the penetrating fibers, a substantial number of ectopic neurons appeared in the subserosal and longitudinal muscle layers of W/W(v) mice, whereas only a few ectopic neurons appeared in wildtype mice. Such ectopic neurons expressed either excitatory or inhibitory intrinsic motor neuron markers and formed ganglion-like structures, including glial cells, synaptic vesicles and basal lamina. Furthermore, oral administration of imatinib, an inhibitor of c-Kit and an anticancer agent for gastrointestinal stromal tumors, markedly induced appearance of ectopic neurons after BAC treatment, even in wildtype mice. These results suggest that adult neurogenesis in the ENS is negatively regulated by c-Kit signaling in vivo.

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

    Science.gov (United States)

    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.

  17. Preservative toxicity in glaucoma medication: clinical evaluation of benzalkonium chloride-free 0.5% timolol eye drops

    Science.gov (United States)

    Rosin, Lauren M; Bell, Nicholas P

    2013-01-01

    Timolol (generic name) is a frequently used medication for the control of glaucoma. Benzalkonium chloride (BAK) is a commonly used preservative in ophthalmic solutions with a broad range of antimicrobial activity; however, this nonspecificity can result in toxicity. Adverse effects attributed to BAK, including conjunctival inflammation and fibrosis, tear film instability, corneal cytotoxicity, anterior chamber inflammation, trabecular meshwork cell apoptosis, cataract development, macular edema, and even systemic effects, have been well documented. These effects can lead to ocular discomfort, poor intraocular pressure control, glaucoma surgery failure, and decreased patient compliance. BAK use in topical medications has decreased recently as newer and less toxic preservatives have become available. Yet these preservatives still exert some toxic effects, especially in patients with chronic eye disease who use multiple drops over extended periods of time. Thus, attempts to reduce overall preservative loads for patients are important, whether it be decreasing the amount of preservative, decreasing the total number of drops patients use, or eliminating preservatives entirely. A preservative-free formulation of timolol, TIMOPTIC® in OCUDOSE®, is available in unit-dose vials. Preservative-free unit-dose vials minimize toxic adverse effects and are a good option for patients with ocular surface disease, on long-term multidrop therapy, or who simply do not tolerate the effects of preservatives due to discomfort. PMID:24204115

  18. Suppression of c-Kit signaling induces adult neurogenesis in the mouse intestine after myenteric plexus ablation with benzalkonium chloride

    Science.gov (United States)

    Tamada, Hiromi; Kiyama, Hiroshi

    2016-01-01

    Adult neurogenesis rarely occurs in the enteric nervous system (ENS). In this study, we demonstrated that, after intestinal myenteric plexus (MP) ablation with benzalkonium chloride (BAC), adult neurogenesis in the ENS was significantly induced in c-kit loss-of-function mutant mice (W/Wv). Almost all neurons and fibers in the MP disappeared after BAC treatment. However, 1 week after ablation, substantial penetration of nerve fibers from the non-damaged area was observed in the MP, longitudinal muscle and subserosal layers in both wildtype and W/Wv mice. Two weeks after BAC treatment, in addition to the penetrating fibers, a substantial number of ectopic neurons appeared in the subserosal and longitudinal muscle layers of W/Wv mice, whereas only a few ectopic neurons appeared in wildtype mice. Such ectopic neurons expressed either excitatory or inhibitory intrinsic motor neuron markers and formed ganglion-like structures, including glial cells, synaptic vesicles and basal lamina. Furthermore, oral administration of imatinib, an inhibitor of c-Kit and an anticancer agent for gastrointestinal stromal tumors, markedly induced appearance of ectopic neurons after BAC treatment, even in wildtype mice. These results suggest that adult neurogenesis in the ENS is negatively regulated by c-Kit signaling in vivo. PMID:27572504

  19. Assessment of corneal epithelial integrity after acute exposure to ocular hypotensive agents preserved with and without benzalkonium chloride.

    Science.gov (United States)

    Whitson, Jess T; Cavanagh, H Dwight; Lakshman, Neema; Petroll, W Matthew

    2006-01-01

    The corneal toxicity of 2 intraocular pressure-lowering agents was compared in a rabbit cornea model with New Zealand White rabbits. Corneal epithelial morphology and cell size were assessed by in vivo confocal microscopy. Baseline microscopic examinations were performed on 1 eye of each animal. Two weeks later, the eyes were bathed for 3 min in travoprost 0.004% preserved without benzalkonium chloride (BAK( or latanoprost 0.005% preserved with 0.02% BAK; the eyes were then rinsed with balanced salt solution, and the corneas were again examined by confocal microscopy (n=4/group). A second group of animals was exposed to the medications through a dosing regimen of 1 drop/min (lpar3 drops total) (n=4/group). In eyes treated with travoprost without BAK (3-min bath), superficial epithelial cells were similar to baseline, as indicated by their visible cell borders and bright nuclei. In contrast, the surface cells in eyes treated with latanoprost were significantly smaller and brighter and had less distinct borders. Surface cell size was significantly smaller as compared with baseline size and as compared with rabbits treated with travoprost without BAK for 3 min. Similar effects on corneal epithelial cell morphology were observed with the 1-drop/min dosing regimen. In this rabbit model, travoprost 0.004% preserved without BAK did not cause corneal epithelial toxicity; latanoprost 0.005% induced superficial cell loss, most likely caused by the presence of a relatively high concentration of BAK (0.02%).

  20. Long‐term recovery of the human corneal endothelium after toxic injury by benzalkonium chloride

    Science.gov (United States)

    Hughes, E H; Pretorius, M; Eleftheriadis, H; Liu, C S C

    2007-01-01

    Introduction The inadvertent intra‐ocular administration of benzalkonium chloride‐preserved hydroxypropyl methylcellulose during cataract surgery at another hospital in 1999 resulted in toxic corneal endothelial injury and profound postoperative corneal oedema as a result of endothelial decompensation. The long‐term effect of this adverse event was assessed. Methods All 19 patients were invited to return for examination including corneal endothelial specular microscopy and pachymetry seven years after the incident. Results were compared with data from one year after the incident. Results Five patients attended for examination, one had received a penetrating keratoplasty and was, therefore, excluded. Ten patients had died and four had moved out of the region and were unable to attend. All four study patients were pain free and achieved 6/12 or better. Mean central corneal thickness reduced by 13% from 652.6 μm at one year to 563.4 μm. Mean central corneal endothelial cell density (n  =  3) increased 28% from 663.7 cells/mm2 at one year to 835.7 cells/mm2 (p<0.05). Conclusions After toxic injury, corneal endothelial function may have a remarkable capacity for recovery even after the first postoperative year. The rise in central endothelial cell density may represent cell migration from less affected areas or cellular proliferation. Should this unfortunate event recur, clinicians may expect continued recovery beyond one year. PMID:17504856

  1. Subminimal Inhibitory Concentrations of the Disinfectant Benzalkonium Chloride Select for a Tolerant Subpopulation of Escherichia coli with Inheritable Characteristics

    Directory of Open Access Journals (Sweden)

    Solveig Langsrud

    2012-03-01

    Full Text Available Exposure of Escherichia coli to a subminimal inhibitory concentration (25% below MIC of benzalkonium chloride (BC, an antimicrobial membrane-active agent commonly used in medical and food-processing environments, resulted in cell death and changes in cell morphology (filamentation. A small subpopulation (1–5% of the initial population survived and regained similar morphology and growth rate as non-exposed cells. This subpopulation maintained tolerance to BC after serial transfers in medium without BC. To withstand BC during regrowth the cells up regulated a drug efflux associated gene (the acrB gene, member of the AcrAB-TolC efflux system and changed expression of outer membrane porin genes (ompFW and several genes involved in protecting the cell from the osmotic- and oxidative stress. Cells pre-exposed to osmotic- and oxidative stress (sodium chloride, salicylic acid and methyl viologen showed higher tolerance to BC. A control and two selected isolates showing increased BC-tolerance after regrowth in BC was genome sequenced. No common point mutations were found in the BC- isolates but one point mutation in gene rpsA (Ribosomal protein S1 was observed in one of the isolates. The observed tolerance can therefore not solely be explained by the observed point mutation. The results indicate that there are several different mechanisms responsible for the regrowth of a tolerant subpopulation in BC, both BC-specific and general stress responses, and that sub-MIC of BC may select for phenotypic variants in a sensitive E. coli culture.

  2. A capillary liquid chromatography method for benzalkonium chloride determination as a component or contaminant in mixtures of biocides.

    Science.gov (United States)

    Prieto-Blanco, M C; Argente-García, A; Campíns-Falcó, P

    2016-01-29

    A method for quantifying benzalkonium chloride (BAK), an alkyl dimethyl benzyl ammonium compound, in several biocides formulations is proposed. A tertiary amine like N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine (TA) and a straight-chain alkyl ammonium compound like trimethyl-tetradecyl ammonium chloride (TMTDAC), have been employed as trade surfactants besides BAK. Two capillary analytical columns with different polarities are tested: inertsil CN-3 capillary column (150mm×0.5mm i.d., 3μm particle diameter) and a non endcapped Zorbax C18 capillary column (35mm×0.5mm i.d., 5μm particle diameter). This latter column provided the best separation of the BAK homologues in less than 12min using acetonitrile:acetate buffer (50mM, pH 5) 85:15 at 20μLmin(-1). The proposed method combines on-line in-tube solid-phase microextraction (IT-SPME) coupled to capillary liquid chromatography (CapLC) and UV diode array detection. Matrix effect was present when TA were in excess to BAK. If TMTDAC is the co-biocide, matrix effect is always present. A decreasing of analytical response mainly for C12-BAK homologue was found using both chromatographic columns. The charged amount of mixture in the system was the most important parameter for obtaining reliable results. 1mL was the on line processed sample volume optimum for concentrations lower than 35μgmL(-1) of total surfactants. LODs were 0.03μgmL(-1) and 0.006μgmL(-1) for C12-BAK and C14-BAK, respectively. This method is also of use to evaluate the unwanted presence of BAK in biocide formulations due to industrial processes.

  3. Subminimal Inhibitory Concentrations of the Disinfectant Benzalkonium Chloride Select for a Tolerant Subpopulation of Escherichia coli with Inheritable Characteristics

    Science.gov (United States)

    Moen, Birgitte; Rudi, Knut; Bore, Erlend; Langsrud, Solveig

    2012-01-01

    Exposure of Escherichia coli to a subminimal inhibitory concentration (25% below MIC) of benzalkonium chloride (BC), an antimicrobial membrane-active agent commonly used in medical and food-processing environments, resulted in cell death and changes in cell morphology (filamentation). A small subpopulation (1–5% of the initial population) survived and regained similar morphology and growth rate as non-exposed cells. This subpopulation maintained tolerance to BC after serial transfers in medium without BC. To withstand BC during regrowth the cells up regulated a drug efflux associated gene (the acrB gene, member of the AcrAB-TolC efflux system) and changed expression of outer membrane porin genes (ompFW) and several genes involved in protecting the cell from the osmotic- and oxidative stress. Cells pre-exposed to osmotic- and oxidative stress (sodium chloride, salicylic acid and methyl viologen) showed higher tolerance to BC. A control and two selected isolates showing increased BC-tolerance after regrowth in BC was genome sequenced. No common point mutations were found in the BC- isolates but one point mutation in gene rpsA (Ribosomal protein S1) was observed in one of the isolates. The observed tolerance can therefore not solely be explained by the observed point mutation. The results indicate that there are several different mechanisms responsible for the regrowth of a tolerant subpopulation in BC, both BC-specific and general stress responses, and that sub-MIC of BC may select for phenotypic variants in a sensitive E. coli culture. PMID:22605968

  4. Short term comparative study of topical 2% carteolol with and without benzalkonium chloride in healthy volunteers

    Science.gov (United States)

    Baudouin, C.; de Lunardo, C.

    1998-01-01

    AIM—A crossover, randomised double blind study was undertaken in 30 healthy volunteers, in order to compare the tolerance of 2% carteolol with and without preservative in short term use.
METHODS—Complete ophthalmic examinations were performed before and 30, 60, and 180 minutes after instillation of one drop of the solution, and after 3 days of preservative treatment. After a 5 day washout, the same examinations were done with the second drug.
RESULTS—Results showed good general tolerance for both formulations. No significant difference in subjective tolerance, corneal aesthesiometry, punctuate keratitis, Schirmer's test, intraocular pressure (IOP) decrease (about 25% in the two groups at 3 hours, 10% after 3 days of treatment), resting cardiac frequency, or blood pressure was observed. However, break up time was significantly reduced from baseline by preserved carteolol both at 3 hours (10.40 (5.9) seconds to 6.15 (3.9) seconds, p=0.001) and after 3 days (7.72 (5.5) seconds, p=0.04). Preservative free carteolol did not significantly change the break up time (baseline 9.08 (5.7) seconds; 3 hours = 7.88 (5.5) seconds, not significant; day 3 = 8.35 (5.8), non-significant).
CONCLUSIONS—These results confirm that carteolol is well tolerated, either with or without preservative. The preservative free group showed better stability of the tear film, without loss of effect on IOP. This difference, although mild in the healthy young subjects in the present study could be much more relevant in those patients treated long term, older patients, and/or those suffering from ocular surface disorders. In such instances, preservative free drugs could be of potential benefit to protect the lacrimal fluid integrity and corneoconjunctival surface.

 Keywords: glaucoma; carteolol; benzalkonium; preservatives; β blockers PMID:9536878

  5. Research on Quality Differences in Benzalkonium Chloride from Domestic and Abroad%国内外苯扎氯铵质量差异的研究

    Institute of Scientific and Technical Information of China (English)

    熊亚群; 刘雁鸣; 龙海燕; 彭琳; 艾俊涛

    2016-01-01

    目的::比较国内外苯扎氯铵的质量差异,为我国苯扎氯铵质量标准的修订提供参考。方法:采用《美国药典》2015年版(USP 38)中苯扎氯铵项下HPLC法测定国内外样品的烷基组成比率。分别照《中国药典》2015年版、USP 38中苯扎氯铵项下化学滴定法测定总含量。结果:烷基组成比率结果表明,国产与进口样品的不合格率分别为100%和50%。按两国药典方法计算含量的差值显示,国产与进口样品的总含量变化分别为3.86%~4.15%和1.15%~3.90%。结论:国内外苯扎氯铵的质量存在较大差异,建议我国药典参照USP 38增订烷基组成比率的测定,修正苯扎氯铵总含量的计算公式,提高该品种的质量标准。%Objective:To compare the quality differences in benzalkonium chloride samples from domestic and abroad to provide references for the quality standard revision for benzalkonium chloride in Chinese pharmacopoeia. Methods: The ratio of alkyl compo-nents was determined according to the method described in USP 38, and the total content of benzalkonium chloride was determined ac-cording to the method recorded in Chinese Pharmacopoeia (2015 edition) and USP 38, respectively. Results:According to the results of composition ratio of alkyl, the fraction defective of domestic samples and imported samples was 100% and 50%, respectively. The content difference between the values calculated by the methods in the two pharmacopoeias showed that the total content of domestic samples changed from 3. 86% to 4. 15%, and that of imported samples changed from 1. 15% to 3. 90%. Conclusion:There are sig-nificant differences in the quality of benzalkonium chloride between domestic samples and imported samples. It is recommended that the ratio of alkyl components should be supplemented in our pharmacopoeia referring to the method in USP 38 and the total content calcula-tion formula for benzalkonium chloride should be revised to improve

  6. [Preservative substances - the daily dose of benzalkonium chloride in glaucoma treatment from the patients point of view].

    Science.gov (United States)

    Výborný, P; Sičáková, S; Veselá Flórová, Z

    2014-06-01

    The author calculated the daily dose of Benzalkonium Chloride (BAC) in eye drops used in glaucoma treatment from the patients point of view, which means the real amount of BAC applied in the conjunctival sac. The information about BAC concentration in 1 milliliter (mL) do not offer sufficient picture about real circumstances, because the size of the drop, especially after the introducing of the use of generic products in clinical practice in specific anti-glaucomatic drugs, differs significantly. The daily dose of BAC may have substantial significance in the patients treatment tolerance. The overview of BAC daily dose in single therapeutic groups and drugs follows: betablockers: Timo-COMOD 0, Arutimol 2.6, Vistagan 2.8, Timolol-POS 3.0, Arteoptic 3.7, Betoptic S 4.8, Timoptol MSD 6.3, Betoptic 10.0; alpha-mimetics: Alphagan 3.5, Luxfen 3.5, Aruclonin 7.1; derivates of prostaglandine, prostamides: Taflotan 0, Monopost 0, Lumigan 1.4, Unilat 3.1, Travatan 3.9, Latanoprost Apotex 4.3, Rescula 5.8, Latanoprost POS 5.9, Xalatan 6.0, Latanoprost Ratiopharm 6.0, Latanoprost Actavis 6.0, Latanoprost Arrow 6.0, Arulatan 5.4, Latalux 6.0, Glaucotens 6.0, Xaloptic 6.0, Solusin 6.1; carboanhydrase inhibitors: Batidor 3.8, Azopt 4.8, Trusopt 5.4, Oftidor 8.1; fixed combinations: Ganfort 1.4, Dorzolamid/timolol TEVA 2.8, Combigan 3.2, Duotrav 4.3, Cosopt 5.6, Xalacom 6.0, Glaucotima 6.0, Latanoprost/timolol Apotex 6.3, Azarga 6.4, Dorzogen Combi 6.5, and Dozotima 8.8 µl.

  7. Heavy-Metal and Benzalkonium Chloride Resistance of Listeria monocytogenes Isolates from the Environment of Turkey-Processing Plants▿ †

    Science.gov (United States)

    Mullapudi, S.; Siletzky, R. M.; Kathariou, S.

    2008-01-01

    The resistance of Listeria monocytogenes to cadmium and arsenic has been used extensively for strain subtyping. However, limited information is available on the prevalence of such resistance among isolates from the environment of food-processing plants. In addition, it is not known whether the resistance of such isolates to heavy metals may correlate with resistance to quaternary ammonium compounds extensively used as disinfectants in the food-processing industry. In this study, we characterized 192 L. monocytogenes isolates (123 putative strains) from the environment of turkey-processing plants in the United States for resistance to cadmium and arsenic and to the quaternary ammonium disinfectant benzalkonium chloride (BC). Resistance to cadmium was significantly more prevalent among strains of serotypes 1/2a (or 3a) and 1/2b (or 3b) (83% and 74%, respectively) than among strains of the serotype 4b complex (19%). Resistance to BC was encountered among 60% and 51% of the serotype 1/2a (or 3a) and 1/2b (or 3b) strains, respectively, and among 7% of the strains of the serotype 4b complex. All BC-resistant strains were also resistant to cadmium, although the reverse was not always the case. In contrast, no correlation was found between BC resistance and resistance to arsenic, which overall was low (6%). Our findings suggest that the processing environment of turkey-processing plants may constitute a reservoir for L. monocytogenes harboring resistance to cadmium and to BC and raise the possibility of common genetic elements or mechanisms mediating resistance to quaternary ammonium disinfectants and to cadmium in L. monocytogenes. PMID:18192428

  8. Coselection of Cadmium and Benzalkonium Chloride Resistance in Conjugative Transfers from Nonpathogenic Listeria spp. to Other Listeriae

    Science.gov (United States)

    Katharios-Lanwermeyer, S.; Rakic-Martinez, M.; Elhanafi, D.; Ratani, S.; Tiedje, J. M.

    2012-01-01

    Resistance to the quaternary ammonium disinfectant benzalkonium chloride (BC) may be an important contributor to the ability of Listeria spp. to persist in the processing plant environment. Although a plasmid-borne disinfectant resistance cassette (bcrABC) has been identified in Listeria monocytogenes, horizontal transfer of these genes has not been characterized. Nonpathogenic Listeria spp. such as L. innocua and L. welshimeri are more common than L. monocytogenes in food processing environments and may contribute to the dissemination of disinfectant resistance genes in listeriae, including L. monocytogenes. In this study, we investigated conjugative transfer of resistance to BC and to cadmium from nonpathogenic Listeria spp. to other nonpathogenic listeriae, as well as to L. monocytogenes. BC-resistant L. welshimeri and L. innocua harboring bcrABC, along with the cadmium resistance determinant cadA2, were able to transfer resistance to other nonpathogenic listeriae as well as to L. monocytogenes of diverse serotypes, including strains from the 2011 cantaloupe outbreak. Transfer among nonpathogenic Listeria spp. was noticeably higher at 25°C than at 37°C, whereas acquisition of resistance by L. monocytogenes was equally efficient at 25 and 37°C. When the nonpathogenic donors were resistant to both BC and cadmium, acquisition of cadmium resistance was an effective surrogate for transfer of resistance to BC, suggesting coselection between these resistance attributes. The results suggest that nonpathogenic Listeria spp. may behave as reservoirs for disinfectant and heavy metal resistance genes for other listeriae, including the pathogenic species L. monocytogenes. PMID:22904051

  9. Localization and Expression of Zonula Occludins-1 in the Rabbit Corneal Epithelium following Exposure to Benzalkonium Chloride

    Science.gov (United States)

    Zhang, Zhenhao; Chen, Lelei; Xie, Hui; Dong, Nuo; Chen, Yongxiong; Liu, Zuguo

    2012-01-01

    Preservatives are a major component of the ophthalmic preparations in multi-dose bottles. The purpose of this study was to investigate the acute effect of benzalkonium chloride (BAC), a common preservative used in ophthalmic preparations, on the localization and expression of zonula occludens (ZO)-1 in the rabbit corneal epithelium in vivo. BAC at 0.005%, 0.01%, or 0.02% was topically applied to one eye each of albino rabbits at 5 min intervals for a total of 3 times. The contralateral untreated eyes served as controls. The following clinical indications were evaluated: Schirmer test, tear break-up time (BUT), fluorescein and rose Bengal staining. The structure of central cornea was examined by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance and permeability to carboxy fluorescein. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of ZO-1, 2, occludin, claudin-1, Ki67 and cell apoptosis in the epithelium. The expression of ZO-1 in the corneal epithelium was also examined by western blot and reverse transcription-polymerase chain reaction analyses. Exposure to BAC resulted in higher rose Bengal staining scores while no significant changes in BUT, Schirmer and corneal florescein scores. It also induced corneal epithelial cell damage, dispersion of ZO-1 and ZO-2 from their normal locus at the superficial layer and disruption of epithelial barrier function. However, the amounts of ZO-1 mRNA and protein in the corneal epithelium were not affected by BAC treatment. Exposure to BAC can quickly impair the corneal epithelium without tear deficiency. BAC disrupts the tight junctions of corneal epithelium between superficial cells in the rabbit corneal epithelium in vivo. PMID:22815857

  10. Localization and expression of zonula occludins-1 in the rabbit corneal epithelium following exposure to benzalkonium chloride.

    Directory of Open Access Journals (Sweden)

    Wensheng Chen

    Full Text Available Preservatives are a major component of the ophthalmic preparations in multi-dose bottles. The purpose of this study was to investigate the acute effect of benzalkonium chloride (BAC, a common preservative used in ophthalmic preparations, on the localization and expression of zonula occludens (ZO-1 in the rabbit corneal epithelium in vivo. BAC at 0.005%, 0.01%, or 0.02% was topically applied to one eye each of albino rabbits at 5 min intervals for a total of 3 times. The contralateral untreated eyes served as controls. The following clinical indications were evaluated: Schirmer test, tear break-up time (BUT, fluorescein and rose Bengal staining. The structure of central cornea was examined by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance and permeability to carboxy fluorescein. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of ZO-1, 2, occludin, claudin-1, Ki67 and cell apoptosis in the epithelium. The expression of ZO-1 in the corneal epithelium was also examined by western blot and reverse transcription-polymerase chain reaction analyses. Exposure to BAC resulted in higher rose Bengal staining scores while no significant changes in BUT, Schirmer and corneal florescein scores. It also induced corneal epithelial cell damage, dispersion of ZO-1 and ZO-2 from their normal locus at the superficial layer and disruption of epithelial barrier function. However, the amounts of ZO-1 mRNA and protein in the corneal epithelium were not affected by BAC treatment. Exposure to BAC can quickly impair the corneal epithelium without tear deficiency. BAC disrupts the tight junctions of corneal epithelium between superficial cells in the rabbit corneal epithelium in vivo.

  11. Coselection of cadmium and benzalkonium chloride resistance in conjugative transfers from nonpathogenic Listeria spp. to other Listeriae.

    Science.gov (United States)

    Katharios-Lanwermeyer, S; Rakic-Martinez, M; Elhanafi, D; Ratani, S; Tiedje, J M; Kathariou, S

    2012-11-01

    Resistance to the quaternary ammonium disinfectant benzalkonium chloride (BC) may be an important contributor to the ability of Listeria spp. to persist in the processing plant environment. Although a plasmid-borne disinfectant resistance cassette (bcrABC) has been identified in Listeria monocytogenes, horizontal transfer of these genes has not been characterized. Nonpathogenic Listeria spp. such as L. innocua and L. welshimeri are more common than L. monocytogenes in food processing environments and may contribute to the dissemination of disinfectant resistance genes in listeriae, including L. monocytogenes. In this study, we investigated conjugative transfer of resistance to BC and to cadmium from nonpathogenic Listeria spp. to other nonpathogenic listeriae, as well as to L. monocytogenes. BC-resistant L. welshimeri and L. innocua harboring bcrABC, along with the cadmium resistance determinant cadA2, were able to transfer resistance to other nonpathogenic listeriae as well as to L. monocytogenes of diverse serotypes, including strains from the 2011 cantaloupe outbreak. Transfer among nonpathogenic Listeria spp. was noticeably higher at 25°C than at 37°C, whereas acquisition of resistance by L. monocytogenes was equally efficient at 25 and 37°C. When the nonpathogenic donors were resistant to both BC and cadmium, acquisition of cadmium resistance was an effective surrogate for transfer of resistance to BC, suggesting coselection between these resistance attributes. The results suggest that nonpathogenic Listeria spp. may behave as reservoirs for disinfectant and heavy metal resistance genes for other listeriae, including the pathogenic species L. monocytogenes.

  12. Development and Validation of a Precise and Stability Indicating LC Method for the Determination of Benzalkonium Chloride in Pharmaceutical Formulation Using an Experimental Design

    Directory of Open Access Journals (Sweden)

    Harshal K. Trivedi

    2010-01-01

    Full Text Available A simple, precise, shorter runtime and stability indicating reverse-phase high performance liquid chromatographic method has been developed and validated for the quantification of benzalkonium chloride (BKC preservative in pharmaceutical formulation of sparfloxacin eye drop. The method was successfully applied for determination of benzalkonium chloride in various ophthalmic formulations like latanoprost, timolol, dexametasone, gatifloxacin, norfloxacin, combination of moxifloxacin and dexamethasone, combination of nepthazoline HCl, zinc sulphate and chlorpheniramine maleate, combination of tobaramycin and dexamethasone, combination of phenylephrine HCl, naphazoline HCl, menthol and camphor. The RP-LC separation was achieved on an Purospher Star RP-18e 75 mm × 4.0 mm, 3.0 μ in the isocratic mode using buffer: acetonitrile (35: 65, v/v, as the mobile phase at a flow rate of 1.8 mL/min. The methods were performed at 215 nm; in LC method, quantification was achieved with PDA detection over the concentration range of 50 to 150 μg/mL. The method is effective to separate four homologs with good resolution in presence of excipients, sparfloxacin and degradable compound due to sparfloxacin and BKC within five minutes. The method was validated and the results were compared statistically. They were found to be simple, accurate, precise and specific. The proposed method was validated in terms of specificity, precision, recovery, solution stability, linearity and range. All the validation parameters were within the acceptance range and concordant to ICH guidelines.

  13. Antimicrobial properties of titanium soaked with benzalkonium chloride solution%纯钛经苯扎氯铵浸泡后的抗菌性能的研究

    Institute of Scientific and Technical Information of China (English)

    李佳; 廉云敏; 高岚

    2015-01-01

    Objective:To study the antibacterial properties of pure titanium treated with benzalkonium chloride solution.Meth-ods:10 mm ×10 mm ×1 mm titanium specimens were processed by the benzalkonium chloride solution at 1%,0.5% and 0.1%respectively followed by treatment in the cultured bacterial suspension,and then the antibacterial properties of the titanium plates were examined.Additionally,the thermal cycling test was carried out for the 1% benzalkonium chloride-treated titanium plates, and subsequently put the plates into cultured bacterial suspension,the duration of antibacterial properties was observed.Results:0.5% and 1% benzalkonium chloride solution-treated titanium plates significantly inhibited the growth of candida albicans(P <0. 05),1% solution was more effective than 0.5% solution.After 1 000 and 2 500 thermal cycling,the pure titanium still retained the antibacterial ability,but the plates treated by 5 000 cycling showed no antibacterial effect.Conclusion:A certain concentration of benzalkonium chloride can make the pure titanium obtain antibacterial properties.The treated plates may maintain the antibacte-rial properties for a minimum of 3 months.%目的:通过用苯扎氯铵溶液浸泡处理钛片,了解该方法能否使纯钛具有抗菌性及抗菌性持续的时间。方法:制作10 mm ×10 mm ×1 mm 的钛片试件,用不同浓度的苯扎氯铵溶液浸泡处理,菌悬液浸泡培养,检测有无抗菌性。用1%的苯扎氯铵溶液浸泡处理试件,进行冷热循环实验后再进行细菌培养,检测抗菌性的持续时间。结果:不同浓度的苯扎氯铵溶液处理纯钛后对白色念珠菌生长的抑制效果不同,0.5%和1%的苯扎氯铵溶液浸泡纯钛可使其产生抗菌性(均有显著差异,P <0.05),1%的苯扎氯铵溶液效果更佳。冷热循环1000次和2500次后纯钛仍具有抗菌性,5000次时与未进行抗菌处理效果相同。结论:一定浓度的苯扎氯铵

  14. Research on the Stability of a Rabbit Dry Eye Model Induced by Topical Application of the Preservative Benzalkonium Chloride

    Science.gov (United States)

    Luan, Shaohong; Wan, Pengxia; Li, Naiyang; Tang, Jing; Han, Yu; Xiong, Cuiju; Wang, Zhichong

    2012-01-01

    Background Dry eye is a common disease worldwide, and animal models are critical for the study of it. At present, there is no research about the stability of the extant animal models, which may have negative implications for previous dry eye studies. In this study, we observed the stability of a rabbit dry eye model induced by the topical benzalkonium chloride (BAC) and determined the valid time of this model. Methods and Findings Eighty white rabbits were randomly divided into four groups. One eye from each rabbit was randomly chosen to receive topical 0.1% BAC twice daily for 2 weeks (Group BAC-W2), 3 weeks (Group BAC-W3), 4 weeks (Group BAC-W4), or 5 weeks (Group BAC-W5). Fluorescein staining, Schirmer's tests, and conjunctival impression cytology were performed before BAC treatment (normal) and on days 0, 7, 14 and 21 after BAC removal. The eyeballs were collected at these time points for immunofluorescence staining, hematoxylin and eosin (HE) staining, and electron microscopy. After removing BAC, the signs of dry eye in Group BAC-W2 lasted one week. Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05) and in Group BAC-W5 on day 14 (P<0.05). Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001). Decreased levels of mucin-5 subtype AC (MUC5AC), along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21. Conclusions A stable rabbit dry eye model was induced by topical 0.1% BAC for 5 weeks, and after BAC removal, the signs of dry eye were sustained for 2 weeks (for the mixed type of dry eye) or for at least 3 weeks (for mucin-deficient dry eye). PMID:22438984

  15. Therapeutic Effects of Sodium Hyaluronate on Ocular Surface Damage Induced by Benzalkonium Chloride Preserved Anti-glaucoma Medications

    Institute of Scientific and Technical Information of China (English)

    Xing Liu; Fen-Fen Yu; Yi-Min Zhong; Xin-Xing Guo; Zhen Mao

    2015-01-01

    Background:Long-term use of benzalkonium chloride (BAC)-preserved drugs is often associated with ocular surface toxicity.Ocular surface symptoms had a substantial impact on the glaucoma patients' quality of life and compliance.This study aimed to investigate the effects of sodium hyaluronate (SH) on ocular surface toxicity induced by BAC-preserved anti-glaucoma medications treatment.Methods:Fifty-eight patients (101 eyes),who received topical BAC-preserved anti-glaucoma medications treatment and met the severe dry eye criteria,were included in the analysis.All patients were maintained the original topical anti-glaucoma treatment.In the SH-treated group (56 eyes),unpreserved 0.3% SH eye drops were administered with 3 times daily for 90 days.In the control group (55 eyes),phosphate-buffered saline were administered with 3 times daily for 90 days.Ocular Surface Disease Index (OSDI) questionnaire,break-up time (BUT) test,corneal fluorescein staining,corneal and conjunctival rose Bengal staining,Schirmer test,and conjunctiva impression cytology were performed sequentially on days 0 and 91.Results:Compared with the control group,SH-treated group showed decrease in OSDI scores (Kruskal-Wallis test:H =38.668,P < 0.001),fluorescein and rose Bengal scores (Wilcoxon signed-ranks test:z =-3.843,P< 0.001,and z =-3.508,P < 0.001,respectively),increase in tear film BUT (t-test:t =-10.994,P < 0.001) and aqueous tear production (t-test:t =-10.328,P < 0.001) on day 91.The goblet cell density was increased (t-test:t =-9.981,P < 0.001),and the morphology of the conjunctival epithelium were also improved after SH treatment.Conclusions:SH significantly improved both symptoms and signs of ocular surface damage in patients with BAC-preserved anti-glaucoma medications treatment.SH could be proposed as a new attempt to reduce ocular surface toxicity,and alleviate symptoms of ocular surface damage in BAC-preserved anti-glaucoma medications treatment.

  16. Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

    Science.gov (United States)

    Khoh-Reiter, Su; Jessen, Bart A

    2009-01-01

    Background Benzalkonium chloride (BAC) is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D) corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC) and olopatadine (0.01% BAC) was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T) cell cultures, expression levels (mRNA and protein) of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year) in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC) and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC contained in ophthalmic

  17. Effects of benzalkonium chloride- or polyquad-preserved fixed combination glaucoma medications on human trabecular meshwork cells

    Science.gov (United States)

    Ammar, David A.

    2011-01-01

    Purpose We investigated the potential short and long-term effects in cultured human trabecular meshwork (TM) cells of various topical glaucoma formulations containing different preservatives. Methods We tested the fixed combination medications 0.004% travoprost plus 0.5% timolol preserved with either 0.015% benzalkonium chloride (BAK; DuoTrav®), or with 0.001% polyquad (PQ; DuoTrav® BAK-free); and 0.005% latanoprost plus 0.5% timolol preserved with 0.020% BAK (Xalacom®). Also tested was a range of BAK concentrations (0.001%–0.020%) in balanced salt solution (BSS). Cells were treated for 25 min at 37 °C with solutions diluted 1:10 and 1:100 to mimic the reduced penetration of topical preparations to the anterior chamber. The percentage of live cells was determined immediately after treatment through the uptake of the fluorescent vital dye calcein-AM. To determine any long-term effects, we assayed release of matrix metalloproteinase 9 (MMP-9) and apoptosis 24 h after treatments. Results BAK demonstrated a dose-dependent reduction in TM cell viability, ranging from 71±5% live cells at 0.001% BAK (diluted 1:10) to 33±3% live cells at 0.020% BAK (diluted 1:10). Travoprost (0.004%) plus 0.5% timolol preserved with 0.015% BAK had statistically fewer live TM cells (79±7%) than the same preparation preserved with 0.001% polyquad® (PQ; 93±1%; p<0.001). Latanoprost plus timolol preserved with 0.020% BAK (29±9% live cells) was similar to the 0.020% BAK (33±3%) treatment. However, travoprost plus timolol preserved in 0.015% BAK had significantly more live cells (83±12%) than the 1:10 dilution of 0.015% BAK (49±10%). We also found 0.020% BAK (diluted 1:100) resulted in elevated levels of extracellular MMP-9 at 24 h. Conclusions These results demonstrate that the substitution of the preservative BAK from topical ophthalmic drugs results in greater in vitro viability of TM cells. Travoprost with timolol, but not latanoprost with timolol, countered some of the toxic

  18. Research on the stability of a rabbit dry eye model induced by topical application of the preservative benzalkonium chloride.

    Directory of Open Access Journals (Sweden)

    Chaoyang Li

    Full Text Available BACKGROUND: Dry eye is a common disease worldwide, and animal models are critical for the study of it. At present, there is no research about the stability of the extant animal models, which may have negative implications for previous dry eye studies. In this study, we observed the stability of a rabbit dry eye model induced by the topical benzalkonium chloride (BAC and determined the valid time of this model. METHODS AND FINDINGS: Eighty white rabbits were randomly divided into four groups. One eye from each rabbit was randomly chosen to receive topical 0.1% BAC twice daily for 2 weeks (Group BAC-W2, 3 weeks (Group BAC-W3, 4 weeks (Group BAC-W4, or 5 weeks (Group BAC-W5. Fluorescein staining, Schirmer's tests, and conjunctival impression cytology were performed before BAC treatment (normal and on days 0, 7, 14 and 21 after BAC removal. The eyeballs were collected at these time points for immunofluorescence staining, hematoxylin and eosin (HE staining, and electron microscopy. After removing BAC, the signs of dry eye in Group BAC-W2 lasted one week. Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05 and in Group BAC-W5 on day 14 (P<0.05. Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001. Decreased levels of mucin-5 subtype AC (MUC5AC, along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21. CONCLUSIONS: A stable rabbit dry eye model was induced by topical 0.1% BAC for 5 weeks, and after BAC removal, the signs of dry eye were sustained for 2 weeks (for the mixed type of dry eye or for at least 3 weeks (for mucin-deficient dry eye.

  19. Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

    Directory of Open Access Journals (Sweden)

    Jessen Bart A

    2009-07-01

    Full Text Available Abstract Background Benzalkonium chloride (BAC is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC and olopatadine (0.01% BAC was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T cell cultures, expression levels (mRNA and protein of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC

  20. Safety and acceptability of vaginal disinfection with benzalkonium chloride in HIV infected pregnant women in west Africa: ANRS 049b phase II randomized, double blinded placebo controlled trial. DITRAME Study Group

    Science.gov (United States)

    Msellati, P.; Meda, N.; Leroy, V.; Likikouet, R.; Van de Perre, P.; Cartoux, M.; Bonard, D.; Ouangre, A.; Combe, P.; Gautier-Charpenti..., L.; Sylla-Koko, F.; Lassalle, R.; Dosso, M.; Welffens-Ekra, C.; Dabis, F.; Mandelbrot, L.

    1999-01-01

    OBJECTIVES: To study the tolerance and acceptability in Africa of a perinatal intervention to prevent vertical HIV transmission using benzalkonium chloride disinfection. DESIGN: A randomized, double blinded phase II trial. SETTING: Prenatal care units in Abidjan (Cote d'Ivoire) and Bobo-Dioulasso (Burkina Faso). PATIENTS: Women accepting testing and counselling who were seropositive for HIV-1 and under 37 weeks of pregnancy were eligible. A total of 108 women (54 in each group) enrolled from November 1996 to April 1997, with their informed consent. INTERVENTION: Women self administered daily a vaginal suppository of 1% benzalkonium chloride or matched placebo from 36 weeks of pregnancy, and a single intrapartum dose. The neonate was bathed with 1% benzalkonium chloride solution or placebo within 30 minutes after birth. MAIN OUTCOME MEASURES: Adverse events were recorded weekly, with a questionnaire and speculum examination in women through delivery, and examination of the neonate through day 30. The incidence of genital signs and symptoms in the women and cutaneous or ophthalmological events in newborns were compared between groups on an intent to treat basis. RESULTS: The median duration of prepartum treatment was 21 days (range 0-87 days). Compliance was 87% for prepartum and 69% for intrapartum treatment, and 88% for the neonatal bath, without differences between the two groups. In women, the most frequent event was leucorrhoea; the incidence of adverse events did not differ between treatment groups. In children, the incidence of dermatitis and conjunctivitis did not differ between the benzalkonium chloride and placebo groups (p = 0.16 and p = 0.29, respectively). CONCLUSION: Vaginal disinfection with benzalkonium chloride is a feasible and well tolerated intervention in west Africa. Its efficacy in preventing vertical HIV transmission remains to be demonstrated. 


 PMID:10754950

  1. The toxicity of the quaternary ammonium compound benzalkonium chloride alone and in mixtures with other anionic compounds to bacteria in test systems with Vibrio fischeri and Pseudomonas putida.

    Science.gov (United States)

    Sütterlin, H; Alexy, R; Kümmerer, K

    2008-10-01

    Mixtures of chemicals are present in the aquatic environment but standard testing methods assess only single compounds. One aspect of this question is the importance of the formation of ionic pairs, for example from quaternary ammonium compounds with organic anions, and the significance of the ionic pairs for bacterial toxicity in the aquatic environment. The aim of the present study was to investigate the toxicity of the cationic quaternary ammonium compound benzalkonium chloride (BAC) against aquatic bacteria in the presence of substances commonly found in wastewater, such as the anionic surfactant linear alkylbenzene sulfonate (LAS), naphthalene sulfonic acid (NSA), sodium dodecylsulfonate (SDS), and benzene sulfonic acid (BSA). The growth inhibition test with Pseudomonas putida and the Vibrio fischeri luminescent inhibition test were used to determine the toxicity of single compounds and compound mixtures. The results found in this study indicate that ion pair formation is of minor significance under the test conditions applied here.

  2. Effect of the hand antiseptic agents benzalkonium chloride, povidone-iodine, ethanol, and chlorhexidine gluconate on atopic dermatitis in NC/Nga mice.

    Science.gov (United States)

    Sadakane, Kaori; Ichinose, Takamichi

    2015-01-01

    Antiseptic agents can cause skin irritation and lead to severe problems, especially for individuals with atopic diatheses. We investigated the effect of 4 different antiseptic agents using an atopic dermatitis (AD) model mouse. NC/Nga mice were subcutaneously injected with mite allergen (Dp) to induce AD-like skin lesions (ADSLs), and an application of 0.2% (w/v) benzalkonium chloride (BZK), 10% (w/v) povidone-iodine (PVP-I), 80% (v/v) ethanol (Et-OH), or 0.5% (v/v) chlorhexidine gluconate (CHG) was applied to the ear envelope. BZK induced a significant increase in the severity of the clinical score, infiltration of inflammatory cells, local expression of inflammatory cytokines in subcutaneous tissue, and total serum immunoglobulin (Ig) E. PVP-I increased the clinical score, number of mast cells, and production of inflammatory cytokines, and total serum IgE. Et-OH increased the clinical score and number of inflammatory cells, but showed no effect on serum IgE levels. No differences in any parameters were observed between CHG and the vehicle. Collectively, the results suggest the severity of the ADSL was related in part to the strength of the immunoreaction. These findings suggest that CHG could offer the lowest risk of inducing ADSL in individuals with atopic dermatitis and that medical staff and food handlers with AD could benefit from its use.

  3. Development and Validation of a Precise Method for Determination of Benzalkonium Chloride (BKC Preservative, in Pharmaceutical Formulation of Latanoprost Eye Drops

    Directory of Open Access Journals (Sweden)

    J. Mehta

    2010-01-01

    Full Text Available A simple and precise reversed phase high performance liquid chromatographic method has been developed and validated for the quantification of benzalkonium chloride (BKC preservative in pharmaceutical formulation of latanoprost eye drops. The analyte was chromatographed on a Waters Spherisorb CN, (4.6×250 mm column packed with particles of 5 μm. The mobile phase, optimized through an experimental design, was a 40:60 (v/v mixture of potassium dihydrogen orthophosphate buffer (pH 5.5 and acetonitrile, pumped at a flow rate of 1.0 mL/min at maintaining column temperature at 30 °C. Maximum UV detection was achieved at 210 nm. The method was validated in terms of linearity, repeatability, intermediate precision and method accuracy. The method was shown to be robust, resisting to small deliberate changes in pH, flow rate and composition (organic ratio of the mobile phase. The method was successfully applied for the determination of BKC in a pharmaceutical formulation of latanoprost ophthalmic solution without any interference from common excipients and drug substance. All the validation parameters were within the acceptance range, concordant to ICH guidelines.

  4. Effects of Benzalkonium Chloride, Proxel LV, P3 Hypochloran, Triton X-100 and DOWFAX 63N10 on anaerobic digestion processes.

    Science.gov (United States)

    Flores, German Antonio Enriquez; Fotidis, Ioannis A; Karakashev, Dimitar Borisov; Kjellberg, Kasper; Angelidaki, Irini

    2015-10-01

    In this study, the individual and synergistic toxicity of the following xenobiotics: Benzalkonium Chloride (BKC), Proxel LV (PRX), P3 Hypochloran (HPC), Triton X-100 (TRX), and DOWFAX 63N10 (DWF), on anaerobic digestion (AD) process, was assessed. The experiments were performed in batch and continuous (up-flow anaerobic sludge blanket, UASB) reactors with biochemical-industrial wastewater, as substrate. In batch experiments, half-maximal inhibitory concentrations (IC50) for the tested xenobiotics were found to be 13.1, 1003, 311.5 and 24.3 mg L(-1) for BKC, PRX, DWF and TRX, respectively while HPC did not affect the AD process. Furthermore, the xenobiotics mixture tested did not present any synergistic inhibitory effect on the AD process. In continuous experiments, BKC and xenobiotics' mixture induced even stronger (more than 85%) of inhibition, expressed as IC50, compared to the levels observed from the batch reactors. Oppositely, TRX showed no inhibition in continuous mode, while inhibition was detected at batch mode.

  5. Genetic Characterization of Plasmid-Associated Benzalkonium Chloride Resistance Determinants in a Listeria monocytogenes Strain from the 1998-1999 Outbreak ▿

    Science.gov (United States)

    Elhanafi, Driss; Dutta, Vikrant; Kathariou, Sophia

    2010-01-01

    Quaternary ammonium compounds such as benzalkonium chloride (BC) are widely used as disinfectants in both food processing and medical environments. BC-resistant strains of Listeria monocytogenes have been implicated in multistate outbreaks of listeriosis and have been frequently isolated from food processing plants. However, the genetic basis for BC resistance in L. monocytogenes remains poorly understood. In this study, we have characterized a plasmid (pLM80)-associated BC resistance cassette in L. monocytogenes H7550, a strain implicated in the 1998-1999 multistate outbreak involving contaminated hot dogs. The BC resistance cassette (bcrABC) restored resistance to BC (MIC, 40 μg/ml) in a plasmid-cured derivative of H7550. All three genes of the cassette were essential for imparting BC resistance. The transcription of H7550 BC resistance genes was increased under sublethal (10 μg/ml) BC exposure and was higher at reduced temperatures (4, 8, or 25°C) than at 37°C. The level of transcription was higher at 10 μg/ml than at 20 or 40 μg/ml. In silico analysis suggested that the BC resistance cassette was harbored by an IS1216 composite transposon along with other genes whose functions are yet to be determined. The findings from this study will further our understanding of the adaptations of this organism to disinfectants such as BC and may contribute to the elucidation of possible BC resistance dissemination in L. monocytogenes. PMID:20971860

  6. Conjunctival and corneal reactions in rabbits following short- and repeated exposure to preservative-free tafluprost, commercially available latanoprost and 0.02% benzalkonium chloride

    Science.gov (United States)

    Liang, H; Baudouin, C; Pauly, A; Brignole-Baudouin, F

    2008-01-01

    Aim: To compare the conjunctival and corneal reactions of commercially available solution of latanoprost (Xalatan) and preservative-free (PF) tafluprost in rabbits. Methods: The rabbits received 50 μl of phosphate-buffered saline (PBS), PF-tafluprost 0.0015%, latanoprost 0.005% or benzalkonium chloride (BAK) 0.02%; all solutions were applied at 5 min intervals for a total of 15 times. The ocular surface toxicity was investigated using slit-lamp biomicroscopy examination, flow cytometry (FCM) and on imprints for CD45 and tumour necrosis factor-receptor 1 (TNFR1) conjunctival impression cytology (CIC) and corneal in vivo confocal microscopy (IVCM). Standard immunohistology also assessed inflammatory/apoptotic cells. Results: Clinical observation and IVCM images showed the highest ocular surface toxicity with latanoprost and BAK, while PF-tafluprost and PBS eyes presented almost normal corneoconjunctival aspects. FCM showed a higher expression of CD45+ and TNFR1+ in latanoprost- or BAK-instilled groups, compared with PF-tafluprost and PBS groups. Latanoprost induced fewer positive cells for inflammatory marker expressions in CIC specimens compared with BAK-alone, both of which were higher than with PF-tafluprost or PBS. Immunohistology showed the same tendency of toxic ranking. Conclusion: The authors confirm that rabbit corneoconjunctival surfaces presented a better tolerance when treated with PF-tafluprost compared with commercially available latanoprost or BAK solution. PMID:18723745

  7. Accelerated solvent extraction followed by on-line solid-phase extraction coupled to ion trap LC/MS/MS for analysis of benzalkonium chlorides in sediment samples

    Science.gov (United States)

    Ferrer, I.; Furlong, E.T.

    2002-01-01

    Benzalkonium chlorides (BACs) were successfully extracted from sediment samples using a new methodology based on accelerated solvent extraction (ASE) followed by an on-line cleanup step. The BACs were detected by liquid chromatography/ion trap mass spectrometry (LC/MS) or tandem mass spectrometry (MS/MS) using an electrospray interface operated in the positive ion mode. This methodology combines the high efficiency of extraction provided by a pressurized fluid and the high sensitivity offered by the ion trap MS/MS. The effects of solvent type and ASE operational variables, such as temperature and pressure, were evaluated. After optimization, a mixture of acetonitrile/water (6:4 or 7:3) was found to be most efficient for extracting BACs from the sediment samples. Extraction recoveries ranged from 95 to 105% for C12 and C14 homologues, respectively. Total method recoveries from fortified sediment samples, using a cleanup step followed by ASE, were 85% for C12BAC and 79% for C14-BAC. The methodology developed in this work provides detection limits in the subnanogram per gram range. Concentrations of BAC homologues ranged from 22 to 206 ??g/kg in sediment samples from different river sites downstream from wastewater treatment plants. The high affinity of BACs for soil suggests that BACs preferentially concentrate in sediment rather than in water.

  8. Epidermal Hyperplasia and Elevated HB-EGF are More Prominent in Retinoid Dermatitis Compared with Irritant Contact Dermatitis Induced by Benzalkonium Chloride

    Science.gov (United States)

    Lee, Jung Eun; Chang, Jae Yong; Lee, Sang Eun; Kim, Moon Young; Lee, Jeong Seon; Lee, Min Geol

    2010-01-01

    Background 'Retinoid dermatitis' is a retinoid-induced irritant contact dermatitis (ICD). The mechanism of retinoid dermatitis may be different from that of other ICDs. However, it remains uncertain how topical retinoid induce ICD. Objective We compared several aspects of contact dermatitis induced by topical retinol and benzalkonium chloride (BKC) on hairless mice skin. Methods 2% retinol or 2.5% BKC was applied to hairless mice and transepidermal water loss (TEWL), ear thickness, histologic and immunohistochemical findings were compared. We also compared mRNA expression of inflammatory cytokines, epidermal differential markers, cyclooxygenases (COXs) and heparin binding epidermal growth factor like growth factor (HB-EGF). Results Topical application of 2% retinol and 2.5% BKC increased TEWL and ear thickness in similar intensity. Epidermal hyperplasia was more prominent in retinol treated skin. Proliferating cell nuclear antigen, involucrin and loricrin expression were higher in retinol-treated skin than in BKC-treated skin. Filaggrin, however, was more expressed in BKC-treated skin. The mRNA expression of IL-8, TNF-α, COX-2, involucrin, loricrin and filaggrin were increased in both retinol- and BKC-treated skin in similar intensity. HB-EGF was more significantly increased in retinol-treated skin. Conclusion Elevated HB-EGF and epidermal hyperplasia are more prominent features of retinoid dermatitis than in BKC-induced ICD. PMID:20711265

  9. Antimicrobial susceptibility of listeria monocytogenes from food products

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Knöchel, Susanne; Hasman, Henrik

    2007-01-01

    for susceptibility to ceftiofur, chloramphenicol, ciprofloxacin, erythromycin, florfenicol, penicillin, spectinomycin, streptomycin, tetracycline, tiamulin, trimethoprim, and co-trimoxazole, and the disinfectants benzalkonium chloride and triclosan, by determination of minimum inhibitory concentrations (MICs). All...... isolates were resistant to ceftiofur, but susceptible to the other antibiotics. A single isolate had a MIC of 4 mg/L for ciprofloxacin. For tiamulin. the MIC values were around the breakpoint used. Most isolates had MICs for triclosan at 16 mg/L. The MICs for benzalkonium chloride formed a bimodal...... distribution, with 105 isolates having a MIC of 4 mg/L and 9 isolates MICs of 16 and 32 mg/L. This study showed that Danish isolates of L. monocytogenes have not developed or acquired resistance to antimicrobial agents used for treatment or disinfection, except for benzalkonium chloride. The MICs for triclosan...

  10. Comparison of the Related Substances in Benzalkonium Chloride at Home and Abroad%国内外苯扎氯铵的有关物质比较

    Institute of Scientific and Technical Information of China (English)

    彭琳; 刘雁鸣; 龙海燕; 熊亚群

    2016-01-01

    目的::对药用辅料苯扎氯铵中的有关物质进行测定并比较国内外样品的内在质量。方法:采用高效液相色谱梯度洗脱法,色谱柱:ODS-HYPERSIL C18柱(250 mm ×4.6 mm,5μm);检测波长:210 nm和257 nm(采用PDA检测器);流速:1.0 ml· min-1;柱温:30℃;进样体积:20μl;流动相:A(取己烷磺酸钠1.09 g及磷酸二氢钠6.9 g加水稀释至1000 ml,摇匀,用磷酸调节pH至3.5)-B(甲醇)。结果:国内外样品的苯甲醛残留均较低;国外样品中苯甲醇残留合格,但明显高于国内样品;国内样品中氯化苄含量较高。结论:该方法快速、简便,可用于比较国内外样品中的有关物质,同时为企业合理选择苯扎氯铵提供依据。%Objective:To determine the related substances in benzalkonium chloride used as a pharmaceutical adjuvant, and com-pare the quality at home and abroad. Methods:An HPLC method was used with an ODS-HYPERSIL C18 column(250 mm × 4. 6 mm, 5 μm). The detection wavelength was 210 nm and 257 nm. The flow rate was 1. 0 ml· min-1 and the column temperature was 30℃. The injection volume was 20 ml. The mobile phase was A ( dissolving 1. 09 g sodium1-hexanesulfonate and 6. 9 g sodium dihydrogen phosphate in water, adjusting pH to 3. 5 with phosphoric acid and diluting to 1 000. 0 ml) and B ( methanol) with gradient elution. Results:The content of benzaldehyde in the samples at home and abroad was low. The content of benzyl alcohol in the samples from a-broad was qualified, which was significantly higher than that in the domestic samples. The content of benzyl chloride in the domestic samples was higher than that in the samples from abroad. Conclusion:The method is simple and fast, which is suitable for comparing the related substances of domastic and imported samples. At the same time, the study provides basis for enterprises to choose benzalko-nium chloride rationally.

  11. Efficacy and safety of benzalkonium chloride-free fixed-dose combination of latanoprost and timolol in patients with open-angle glaucoma or ocular hypertension

    Directory of Open Access Journals (Sweden)

    Bhagat P

    2014-06-01

    Full Text Available Purvi Bhagat,1 Kalyani Sodimalla,2 Chandrima Paul,3 Surinder S Pandav,4 Ganesh V Raman,5 Rengappa Ramakrishnan,6 Abhijeet Joshi,7 Atul Raut7 1Glaucoma Clinic, M & J Western Regional Institute of Ophthalmology, Civil Hospital, Ahmedabad, Gujarat, India; 2Glaucoma Department, PBMA’s H.V. Desai Eye Hospital, Maharashtra, India; 3Glaucoma Service, B B Eye Foundation, Kolkata, India; 4Advanced Eye Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 5Glaucoma Clinic, Aravind Eye Hospital, Coimbatore, Tamilnadu, India; 6Glaucoma Clinic, Aravind Eye Hospital, Tirunelveli, Tamilnadu, India; 7Clinical Research Department, Sun Pharma Advanced Research Company Ltd, Mumbai, Maharashtra, India Background: Benzalkonium chloride (BAK is a common preservative in topical ocular preparations; however, prolonged use may lead to deleterious effects on the ocular surface, affecting quality of life and reducing adherence to treatment and overall outcomes. This study compared the intraocular pressure (IOP-lowering efficacy and safety of a novel once-daily, BAK-free, fixed-dose combination of latanoprost plus timolol with latanoprost or timolol administered as monotherapy or concomitantly. Methods: This was a 6-week, randomized, open-label, parallel-group, active-controlled study in patients aged ≥18 years with open-angle glaucoma or ocular hypertension. A total of 227 patients were randomized to either a once-daily, BAK-free, fixed-dose combination of latanoprost 0.005%/timolol 0.5% ophthalmic solution or concomitant administration of once-daily latanoprost 0.005% plus twice-daily timolol 0.5% or once-daily latanoprost 0.005% monotherapy, or twice-daily timolol 0.5% monotherapy. Efficacy end points were assessed at three time points on visits at weeks 1, 2, 4, and 6 versus baseline. Results: The IOP-lowering efficacy of the fixed-dose combination of latanoprost/timolol was similar to that of latanoprost plus timolol administered

  12. Comparative study on the cytotoxic effects of benzalkonium chloride on the Wong-Kilbourne derivative of Chang conjunctival and IOBA-NHC cell lines

    Science.gov (United States)

    Brasnu, E.; Brignole-Baudouin, F.; Riancho, L.; Warnet, J.-M.

    2008-01-01

    Purpose The Wong-Kilbourne derivative of Chang conjunctiva-derived cell line has been widely used for toxicological and functional in vitro studies on the ocular surface. The common reserve to this cell line is the reported contamination with HeLa cells. Thus, the IOBA-NHC spontaneously immortalized conjunctival epithelial cell line has been recently developed and did not show other cell type contamination. Our purpose was to determine whether both cell lines would be equally suitable for in vitro toxicological studies. Therefore, we compared in these two cell types the toxic effects of the preservative, benzalkonium chloride (BAC); its toxicity has been often reported on conjunctival in vivo and in vitro models. Methods The necrotic, apoptotic, and oxidative effects of BAC were evaluated on Chang and IOBA-NHC cell lines using microplate cytofluorometry tests (neutral red, 2,7- dichlorofluorescein diacetate dye [H2DCF-DA], hydroethidine, and Yopro-1), flow cytometry (Annexin V/7-AAD and DNA content tests), and standard immunofluorescence stainings. Cells were exposed to five concentrations of BAC (10−2%, 5.10−3%, 10−3%, 10−4%, and 10−5%) for two incubation times: 15 min of treatment and 15 min of treatment followed by 24 h of cell recovery in complete medium. Results All parameters of toxicity increased in a BAC dose-dependent manner on both cell lines. Conclusions The comparison of BAC toxicity on both cell lines supported the use of IOBA-NHC and Chang cells for toxicological in vitro studies. Drawbacks of both cell lines have to be known and considered in studies performed on these cell lines. PMID:18334956

  13. Co-culture with Listeria monocytogenes within a dual-species biofilm community strongly increases resistance of Pseudomonas putida to benzalkonium chloride.

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    Efstathios Giaouris

    Full Text Available Biofilm formation is a phenomenon occurring almost wherever microorganisms and surfaces exist in close proximity. This study aimed to evaluate the possible influence of bacterial interactions on the ability of Listeria monocytogenes and Pseudomonas putida to develop a dual-species biofilm community on stainless steel (SS, as well as on the subsequent resistance of their sessile cells to benzalkonium chloride (BC used in inadequate (sub-lethal concentration (50 ppm. The possible progressive adaptability of mixed-culture biofilms to BC was also investigated. To accomplish these, 3 strains per species were left to develop mixed-culture biofilms on SS coupons, incubated in daily renewable growth medium for a total period of 10 days, under either mono- or dual-species conditions. Each day, biofilm cells were exposed to disinfection treatment. Results revealed that the simultaneous presence of L. monocytogenes strongly increased the resistance of P. putida biofilm cells to BC, while culture conditions (mono-/dual-species did not seem to significantly influence the resistance of L. monocytogenes biofilm cells. BC mainly killed L. monocytogenes cells when this was applied against the dual-species sessile community during the whole incubation period, despite the fact that from the 2nd day this community was mainly composed (>90% of P. putida cells. No obvious adaptation to BC was observed in either L. monocytogenes or P. putida biofilm cells. Pulsed field gel electrophoresis (PFGE analysis showed that the different strains behaved differently with regard to biofilm formation and antimicrobial resistance. Such knowledge on the physiological behavior of mixed-culture biofilms could provide the information necessary to control their formation.

  14. Cytotoxicity of five fluoroquinolone and two nonsteroidal anti-inflammatory benzalkonium chloride-free ophthalmic solutions in four corneoconjunctival cell lines

    Science.gov (United States)

    Ayaki, Masahiko; Iwasawa, Atsuo; Soda, Mitsutaka; Yaguchi, Shigeo; Koide, Ryohei

    2010-01-01

    Purpose: Epithelial disorders after eye surgery can result in visual deterioration and patient discomfort. Such disorders may be caused by drug toxicity. In the present study, we evaluated the toxicity of ophthalmic solutions, with or without benzalkonium chloride (BAK) as the preservative, used for postoperative care. Methods: A range of commercially available antibiotic and anti-inflammatory ophthalmic solutions used postoperatively (ie, levofloxacin, moxifloxacin, gatifloxacin, norfloxacin, tosufloxacin, dibekacin, cefmenoxime, diclofenac, bromfenac, pranoprofen, betamethasone, and fluoromethorone) were assessed in three corneal cell lines and one conjunctival cell line. All antibiotic solutions were BAK free. Cell viability was determined with the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay after cells had been exposed to the drugs for 48 h. The effects of preservatives on cell viability were also determined. Toxicity was compared using the cell viability score (CVS). Results: Based on results of the MTT assay and CVS, the order of cell viability after exposure to the antibiotic solutions was cefmenoxime ≥ tosufloxicin ≥ dibekacin ≥ levofloxacin ≥ norfloxacin = gatifloxacin = moxifloxacin. For the anti-inflammatory solutions, the order of cell viability was betamethasone ≥ betamethasone + fradiomycin > preservative-free diclofenac ≥ preservative-free bromfenac >> 0.02% fluoromethorone ≥ 0.1% fluoromethorone = diclofenac + preservative = bromfenac + preservative = pranoprofen. The anti-inflammatory drugs were more toxic than the antibiotics. The toxicity of antibiotic drugs against ocular surface cells was dependent on the pharmaceutical components of the solution, whereas that of the anti-inflammatory drugs was dependent on both the pharmaceutical components and the preservatives. Conclusion: Postoperative drug-induced epitheliopathy may be caused primarily by anti-inflammatory drugs. CVS is useful in comparing the

  15. A Comparison of the Effects of Benzalkonium Chloride on Ocular Surfaces between C57BL/6 and BALB/c Mice

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    Qian Yang

    2017-02-01

    Full Text Available Models of benzalkonium chloride (BAC-induced ocular disruption have been created and are widely used in various animals. This study aimed to compare the effects of BAC on the ocular surfaces of C57BL/6 and BALB/c mice. C57BL/6 and BALB/c mice were treated separately with BAC eye-drops at different concentrations. Eyes were evaluated by scoring epithelial disruption, corneal opacity and neovascularization in vivo, and by histological assays with hematoxylin/eosin (H/E and periodic acid-Schiff stainings and by determining the expression of inflammatory factors in vitro on Days 7 and 14. The in vivo corneal epithelial disruption, corneal edema/opacity and neovascularization, which were in accordance with the results of the H/E staining and peaked at Day 7, were observed in a dose-dependent manner in the BAC-treated mice, with more severe signs in the C57BL/6 mice than the BALB/c mice. The loss of conjunctival goblet cells in the conjunctivas and the increasing expression of monocyte chemoattractant protein 1 (MCP-1, growth-regulated protein alpha (GROa and macrophage inflammatory protein-1 alpha (MIP-1a in the corneas were found in a dose-dependent manner in both strains of mice. Topical application of BAC can dramatically disrupt the ocular surfaces of C57BL/6 and BALB/c mice, and the disruptions were much more severe in the C57BL/6 mice that received high doses of BAC.

  16. 15 Month follow up of African children following vaginal cleansing with benzalkonium chloride of their HIV infected mothers during late pregnancy and delivery

    Science.gov (United States)

    Mandelbrot, L; Msellati, P; Meda, N; Leroy, V; Likikouet, R; Van de Perre, P; Dequae-Merchadoux, L; Sylla-Koko, F; Ouangre, A; Ouassa, T; Ramon, R; Gautier-Charpenti..., L; Cartoux, M; Dosso, M; Dabis, F; Welffens-Ekra, C

    2002-01-01

    Objectives: To study mother to child HIV-1 transmission (MTCT) and infant mortality following benzalkonium chloride (BC) disinfection. Methods: A randomised, double blind phase II placebo controlled trial. Women testing positive for HIV-1 infection in prenatal care units in Abidjan, Côte d'Ivoire, and Bobo-Dioulasso, Burkina Faso, from November 1996 to April 1997 were eligible, with their informed consent. Women self administered daily a vaginal suppository of 1% BC (53) or matched placebo (54) from 36 weeks of pregnancy, plus a single dose during labour. The neonate was bathed with 1% BC solution or placebo within 30 minutes after birth. MTCT rate was assessed based on repeated polymerase chain reaction (PCR) and serology results. For the present analysis, children were followed up to 15 months. Results: A total of 107 women were enrolled. Of 103 eligible liveborn children, 23 were HIV infected, 75 uninfected, and five of indeterminate status. MTCT transmission rate was 24.2% overall (95% confidence interval (CI): 14.3% to 30.4%). On an intent to treat basis, the transmission rate did not differ between the two groups (23.5%, CI 13.8 to 38.5, in the BC group and 24.8%, CI 15.0 to 39.6, in the placebo group at 15 months). Similarly, there was no difference in mortality at 15 months (22.9%, CI 13.7 to 36.9, in the BC group and 16.5%, CI 9.0 to 29.4, in the placebo group). Conclusion: This analysis failed to suggest any benefit of BC disinfection on mother to child HIV transmission or perinatal and infant mortality. PMID:12181464

  17. Toxicity research status of benzalkonium chloride on ocular surface%苯扎氯铵的眼表毒性研究现状

    Institute of Scientific and Technical Information of China (English)

    黄彩虹; 陈文生; 陈永雄; 刘祖国

    2014-01-01

    苯扎氯铵是滴眼液中最常用的防腐剂.至今有大量临床及实验研究表明,使用含苯扎氯铵的滴眼液会引起包括细胞凋亡在内的一系列眼表损伤.但最近有临床研究表明眼表正常的患者使用含苯扎氯铵的滴眼液后引起的眼表毒性与苯扎氯铵并无明显联系.有学者认为研究本身的局限性导致了人们对苯扎氯铵的毒性认识存在夸大之嫌.在此,我们总结了近年来有关苯扎氯铵临床及实验研究的众多资料,将对苯扎氯铵的眼表毒性研究现状作一综述.%Benzalkonium chloride (BAC) is the most commonly used preservative in ophthalmic preparations.So far large bodies of clinical and experimental studies have shown that use of topical drugs containing BAC can induce a series of ocular surface diseases,such as apoptosis.However,recently,some clinical studies have shown that ocular toxicity in patients treated with eye drops containing BAC has not apparent correlated with BAC.Some scholars consider that the limitations of the research lead people to recognize the BAC toxicity exaggeratedly.Here we summarize numerous clinical and experimental studies of BAC in the past few years,and focus on reviewing recent researches of the toxic effect of BAC on ocular surfface.

  18. Co-culture with Listeria monocytogenes within a dual-species biofilm community strongly increases resistance of Pseudomonas putida to benzalkonium chloride.

    Science.gov (United States)

    Giaouris, Efstathios; Chorianopoulos, Nikos; Doulgeraki, Agapi; Nychas, George-John

    2013-01-01

    Biofilm formation is a phenomenon occurring almost wherever microorganisms and surfaces exist in close proximity. This study aimed to evaluate the possible influence of bacterial interactions on the ability of Listeria monocytogenes and Pseudomonas putida to develop a dual-species biofilm community on stainless steel (SS), as well as on the subsequent resistance of their sessile cells to benzalkonium chloride (BC) used in inadequate (sub-lethal) concentration (50 ppm). The possible progressive adaptability of mixed-culture biofilms to BC was also investigated. To accomplish these, 3 strains per species were left to develop mixed-culture biofilms on SS coupons, incubated in daily renewable growth medium for a total period of 10 days, under either mono- or dual-species conditions. Each day, biofilm cells were exposed to disinfection treatment. Results revealed that the simultaneous presence of L. monocytogenes strongly increased the resistance of P. putida biofilm cells to BC, while culture conditions (mono-/dual-species) did not seem to significantly influence the resistance of L. monocytogenes biofilm cells. BC mainly killed L. monocytogenes cells when this was applied against the dual-species sessile community during the whole incubation period, despite the fact that from the 2nd day this community was mainly composed (>90%) of P. putida cells. No obvious adaptation to BC was observed in either L. monocytogenes or P. putida biofilm cells. Pulsed field gel electrophoresis (PFGE) analysis showed that the different strains behaved differently with regard to biofilm formation and antimicrobial resistance. Such knowledge on the physiological behavior of mixed-culture biofilms could provide the information necessary to control their formation.

  19. A Comparison of the Effects of Benzalkonium Chloride on Ocular Surfaces between C57BL/6 and BALB/c Mice.

    Science.gov (United States)

    Yang, Qian; Zhang, Yafang; Liu, Xiuping; Wang, Nan; Song, Zhenyu; Wu, Kaili

    2017-02-26

    Models of benzalkonium chloride (BAC)-induced ocular disruption have been created and are widely used in various animals. This study aimed to compare the effects of BAC on the ocular surfaces of C57BL/6 and BALB/c mice. C57BL/6 and BALB/c mice were treated separately with BAC eye-drops at different concentrations. Eyes were evaluated by scoring epithelial disruption, corneal opacity and neovascularization in vivo, and by histological assays with hematoxylin/eosin (H/E) and periodic acid-Schiff stainings and by determining the expression of inflammatory factors in vitro on Days 7 and 14. The in vivo corneal epithelial disruption, corneal edema/opacity and neovascularization, which were in accordance with the results of the H/E staining and peaked at Day 7, were observed in a dose-dependent manner in the BAC-treated mice, with more severe signs in the C57BL/6 mice than the BALB/c mice. The loss of conjunctival goblet cells in the conjunctivas and the increasing expression of monocyte chemoattractant protein 1 (MCP-1), growth-regulated protein alpha (GROa) and macrophage inflammatory protein-1 alpha (MIP-1a) in the corneas were found in a dose-dependent manner in both strains of mice. Topical application of BAC can dramatically disrupt the ocular surfaces of C57BL/6 and BALB/c mice, and the disruptions were much more severe in the C57BL/6 mice that received high doses of BAC.

  20. A New Safety Concern for Glaucoma Treatment Demonstrated by Mass Spectrometry Imaging of Benzalkonium Chloride Distribution in the Eye, an Experimental Study in Rabbits

    Science.gov (United States)

    Brignole-Baudouin, Françoise; Desbenoit, Nicolas; Hamm, Gregory; Liang, Hong; Both, Jean-Pierre; Brunelle, Alain; Fournier, Isabelle; Guerineau, Vincent; Legouffe, Raphael; Stauber, Jonathan; Touboul, David; Wisztorski, Maxence; Salzet, Michel; Laprevote, Olivier; Baudouin, Christophe

    2012-01-01

    We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK) chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining) and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation) and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety-first principle for

  1. A new safety concern for glaucoma treatment demonstrated by mass spectrometry imaging of benzalkonium chloride distribution in the eye, an experimental study in rabbits.

    Directory of Open Access Journals (Sweden)

    Françoise Brignole-Baudouin

    Full Text Available We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety

  2. Determination of benzalkonium chloride in Dextran 70and glycerol eye drops%右旋糖酐70甘油滴眼液中苯扎氯铵含量测定方法研究

    Institute of Scientific and Technical Information of China (English)

    朱样根; 龚楚良

    2012-01-01

    Objective: To determine the content of benzalkonium chloride in Dextran 70 and glycerol eye drops by HPLC. Methods; The chromatographic conditions were as follows; the column was Kromasil C18 (250 mm x 4. 6 mm,5 (um)column;the mobile phase consisted of acetonitrile -0. 03 mol · L-1 sodium dihydrogen phosphate (pH 7. 0 ) ( 43: 57 ) ; the flow rate was 2. 0 mL · min -; the column temperature was 35℃; the detection wavelength was at 214 nm;the injection volume was 20 uX;the separable degree of benzalkonium chloride between C12,C14, C16,should meet rules. Results;The calibration curve of benzalkonium chloride ranged from 1.28-3.00 u,g had good linearity with peak area (r = 0. 9999, n = 7 ) ; The recovery ( n = 6) was 100. 9% ; RSD = 0. 9%. Conclusion: The method is simple, fast, and accurate, with high sensitivity and good repeatability, and can be used for content determination of benzalkonium chloride in Dextran 70 and glycerol eye drops.%目的:建立高效液相色谱法测定右旋糖酐70甘油滴眼液中苯扎氯铵的含量.方法:以氰基硅烷键合硅胶为填充剂;以乙腈-0.03 mol·L-1磷酸二氢钠溶液(用1 mol·L-1氢氧化钠溶液调pH至7.0)(43∶ 57)为流动相;流速:2.0 mL·min -1;柱温:35℃;检测波长214 nm.苯扎氯铵C12、C14、C16之间的分离度应符合规定.结果:苯扎氯铵在1.28~3.00 μg范围内与峰面积线性关系良好(r =0.9999,n=7);平均回收率(n=6)为100.9%,RSD=0.9%.结论:该法操作简便,快速、准确,灵敏度高,重复性好,可用于右旋糖酐70甘油滴眼液中苯扎氯铵含量测定.

  3. Determination of benzalkonium chloride in compound tropicamide eye drops by HPLC%HPLC法测定复方托吡卡胺滴眼液中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    何丹; 杨林

    2013-01-01

    Objective :To establish an HPLC method for detecting the content of Benzalkonium Chloride in Compound Tropicamide Eye Drops .Methods :A Alltech Alltima -CN column (250cm × 4 .6mm ,5μm) was used ,and the mobile phase was 0 .1mol・L -1 NaAc solution -acetonitrile (60 :40) ,HAc was used to adjust pH to 5 ,column temperature was 30℃ ,at a flow rate of 2 .0ml・min -1 and detection wavelength of 254 nm .Results :The linear range of Benzalkonium Chloride was 0 .02~0 .5mg・mL -1 ;The correlation coefficient was 0 .9999 .The average recovery of Benzalkonium Chloride was 98 .91% (RSD=0 .44% ,n=9 ) .Conclusion :The method is accurate ,simple ,rapid and suitable for the quality control of Benzalkonium Chloride in Compound Tropicamide eye drops .%目的:建立超高效液相色谱法测定复方托吡卡胺滴眼液中苯扎氯铵的含量测定方法。方法:色谱柱为Alltech Alltima -CN(250cm ×4.6mm ,5μm),流动相为0.1mol・L -1醋酸钠溶液(用冰醋酸调节pH值至5.0)-乙腈(60:40),检测波长254nm ,流速为2.0ml・min -1,柱温30℃,进样体积50μL。结果:苯扎氯铵在0.02至0.5mg・mL -1浓度范围内线性关系良好(r=0.9999);平均回收率为98.91%,RSD=0.44%(n=9)。结论:该方法准确、简便、快速、可靠,能有效控制复方托吡卡胺滴眼液中苯扎氯铵的含量。

  4. El cloruro de benzalconio: inaceptable para esterilizar o desinfectar instrumental médico o dental Benzalkonium chloride is unacceptable to sterilize or disinfect medical or dental instruments

    Directory of Open Access Journals (Sweden)

    Enrique Acosta-Gío

    2001-12-01

    Full Text Available Objetivo. Comparar la actividad esporicida del cloruro de benzalconio (CB con la del glutaraldehído. Material y métodos. Estudio comparativo, hecho en el Laboratorio de Microbiología de la Facultad de Odontología, Universidad Nacional Autónoma de México (UNAM. Se expusieron esporas de Bacillus subtilis ATCC 9372 a estos germicidas (1 espora x µl sobre un filtro de 0.22 µm. Al completarse el tiempo de contacto, se lavaron las esporas y los filtros fueron incubados sobre agar nutritivo por 72 h a 37ºC. Resultados. El CB no eliminó las esporas de B. subtilis a la concentración de uso, ni aun al incrementar a 15 h su exposición (900 veces el tiempo recomendado. El glutaraldehído al 2% destruyó las esporas después de 10 h. La urea y el cloruro de sodio no mostraron actividad esporicida. Conclusiones. Los resultados confirman que el CB carece de actividad esporicida y ratifican que este compuesto cuaternario de amonio no tiene aplicación como agente esterilizante o como desinfectante de instrumental médico y dental. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.htmlObjective. To compare the sporicidal activity of benzalkonium chloride (BKC with that of glutaraldehyde. Material and Methods. A comparative study was conducted at the microbiology laboratory of Facultad de Odontología, Universidad Nacional Autónoma de México. Bacillus subtilis ATCC 9372 spores were exposed to these germicides (1 spore x mL on a 0.22 mm filter. After completing the contact time the spores were washed and the filters were incubated on nutrient agar for 72 h at 37ºC. Results. BKC did not eliminate B. subtilis spores at the concentration used, not even after increasing contact time to 15 h (900-fold the recommended time. Two percent glutaraldehyde destroyed spores only after 10 h of contact. Urea and sodium chloride showed no sporicidal activity. Conclusions. The results confirm that BKC lacks sporicidal

  5. UV/chlorine as an advanced oxidation process for the degradation of benzalkonium chloride: Synergistic effect, transformation products and toxicity evaluation.

    Science.gov (United States)

    Huang, Nan; Wang, Ting; Wang, Wen-Long; Wu, Qian-Yuan; Li, Ang; Hu, Hong-Ying

    2017-05-01

    Benzalkonium chlorides (BACs), as typical cationic surfactants and biocides widely applied in household and industrial products, have been frequently detected as micropollutants in many aquatic environments. In this study, the combination of UV irradiation and chlorine (UV/chlorine), a newly interested advanced oxidation process, was used to degrade dodecylbenzyldimethylammonium chloride (DDBAC). UV/chlorine showed synergistic effects on DDBAC degradation comparing to UV irradiation or chlorination alone. Radical quenching experiments indicated that degradation of DDBAC by UV/chlorine involved both UV photolysis and radical species oxidation, which accounted for 48.4% and 51.6%, respectively. Chlorine dosage and pH are essential parameters affecting the treatment efficiency of UV/chlorine. The pseudo first order rate constant (kobs, DDBAC) increased from 0.046 min(-1) to 0.123 min(-1) in response to chlorine dosage at 0-150 mg/L, and the degradation percentage of DDBAC within 12 min decreased from 81.4% to 56.6% at pH 3.6-9.5. Five main intermediates were identified and semi-quantified using HPLC-MS/MS and a possible degradation pathway was proposed. The degradation mechanisms of DDBAC by UV/chlorine included cleavage of the benzyl-nitrogen bond and hydrogen abstraction of the alkyl chain. Trichloromethane (TCM), chloral hydrate (CH), trichloropropanone (TCP), dichloropropanone (DCP) and dichloroacetonitrile (DCAN) were detected using GC-ECD. The formation of chlorinated products increased rapidly initially, then decreased (TCM, TCP, DCP and DCAN) or remained stable (CH) with extended treatment. The actual formation of TCM peaked at 30 min (50.3 μg/L), while other chlorinated products did not exceed 10 μg/L throughout the process. Based on the luminescent bacterial assay, DDBAC solution underwent almost complete detoxification subjected to UV/chlorine treatment for 120 min, which is more effective than UV irradiation or chlorination alone.

  6. Kidney alkaline phosphatase in mercuric chloride injected chicks resistant and susceptible to leukosis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, V.L.; McIntyre, J.A.; Bearse, G.E.

    1969-01-01

    Two strains of chickens were selected for resistance and susceptibility to avian leukosis. Researchers found that the resistant chicks retained two to four times as much mercury in the liver and kidneys as did the susceptible chicks following injection of mercuric chloride or phenylmercuric acetate. Differences in alkaline phosphatase in the kidneys of the resistant and susceptible chicks, and the effect of the mercuric chloride injection on the alkaline phosphatase activity were reported in this paper. 19 references, 2 tables.

  7. Studies on Toxicity of Combination of Borneol and Benzalkonium Chloride to Red Blood Cells and Corneal Epithelial Cells in Vitro%冰片与苯扎氯铵合用对红细胞及角膜上皮细胞的损伤效应

    Institute of Scientific and Technical Information of China (English)

    廖南英; 伍海涛; 梁小雯; 刘启德; 宓穗卿; 王宁生

    2014-01-01

    目的:考察冰片与苯扎氯铵合用对红细胞及角膜上皮细胞的毒性。方法实验分为溶剂对照组、冰片组、苯扎氯铵组、冰片+苯扎氯铵组,分别测定各组红细胞半数溶血浓度(HC50)和角膜上皮细胞半数抑制浓度(IC50),根据等辐射分析法和响应面分析法判断联合作用类型和趋势,并观察二者合用对眼角膜上皮细胞增殖的影响。结果苯扎氯铵对红细胞及角膜上皮细胞的毒性作用呈明显的量效关系,加入冰片后能降低其HC50和IC50值。结论冰片与苯扎氯铵对红细胞的溶血效应表现为协同作用,冰片能增强苯扎氯铵对角膜上皮细胞的毒性作用,受损一定程度内的细胞可恢复。%Objective The in vitro hemolytic test and cytotoxicity test were used to study the toxicity of the combination of borneol and benzalkonium chloride to red blood cells and corneal epithelial cells. Methods Suspension of rabbit red blood cells and corneal epithelial cells were treated with different concentrations of borneol , benzalkonium chloride and combination of borneol-benzalkonium. Dose-response assays were firstly carried out to obtain the 50%hemolysis concentration(HC50) of the individual drug group. Then isobolographic analysis and response surface analysis were used to define the type and tendency of interaction between borneol and benzalkonium chloride. The effects of the combination on the proliferation of corneal epithelial cells were also observed. Results The toxicity of benzalkonium chloride to red blood cells and corneal epithelial cells was dose-dependent. The curve of dose-effect showed that HC 50 and IC50 of benzalkonium chloride were decreased after borneol was added. Conclusion Borneol and benzalkonium chloride have synergistic action on the hemolytic effect, and borneol can enhance the toxicity of benzalkonium chloride on corneal epithelial cells. The corneal epithelial cells with certain degrees of

  8. Prenatal susceptibility to carcinogenesis by xenobiotic substances including vinyl chloride.

    OpenAIRE

    Rice, J M

    1981-01-01

    The carcinogenicity of vinyl chloride for experimental animals when administered transplacentally is reviewed in comparison with known transplacental carcinogens, including those that, like vinyl chloride, are dependent on enzyme-mediated metabolic conversion to a reactive intermediate in maternal or fetal tissues. Vinyl chloride is converted by mixed-function oxidases to the reactive metabolite chlorooxirane, the carcinogenicity of which is also reviewed. Vinyl chloride is unequivocally a tr...

  9. Comparative study on bactericidal activity of benzalkonium chloride and dodecyl two propylene triamine%苯扎氯铵与十二烷基二亚丙三胺杀菌活性比较研究

    Institute of Scientific and Technical Information of China (English)

    张丽蓉; 陈维; 邓金花; 宋金武

    2016-01-01

    Objective To compare bactericidal activity of benzalkonium chloride and dodecyl two propylene triamine.Methods Suspension quantitative germicidal test and antibacterial ring test were used to study bactericidal activity of benzalkonium chloride and dodecyl two propylene triamine.Results The average killing logarithm values of Pseudomonas aeruginosa,Escherichia coli and Staphylococcus aureus exposed to the concentration of 500 mg/L of the benzalkonium chloride for 1 min were 5.18,7.02 and 7.13 respectively,the average killing logarithm value of Candida albicans was 4.48.The average killing logarithm values of P.aeruginosa,E.coli and S.aureus exposed to the concentration of 500 mg/L of the dodecyl two propylene triamine for 1 min were 5.84,7.32 and 7.13 respectively,the average killing logarithm value of C.albicans was 4.94.Concentration was 50 mg/L,the antibacterial ring diameters of benzalkonium chloride and dodecyl two propylene triamine were 8.3 mm and 8.2 mm respectively.Conclusion The bactericidal effect of dodecyl two propylene triamine is better than that of benzalkonium chloride,there was no significant difference in antibacterial effect.%目的 比较苯扎氯铵与十二烷基二亚丙三胺的杀菌活性.方法 采用悬液定量杀菌试验和抑菌环试验方法,对苯扎氯铵和十二烷基二亚丙三胺的杀菌活性进行比较研究.结果 用含500 mg/L的苯扎氯铵作用1 min,对铜绿假单胞菌、大肠杆菌和金黄色葡萄球菌的平均杀灭对数值分别为5.18、7.02和7.13,对白色念珠菌的平均杀灭对数值为4.48.用含500 mg/L的十二烷基二亚丙三胺作用1 min,对铜绿假单胞菌、大肠杆菌和金黄色葡萄球菌的平均杀灭对数值分别为5.84、7.32和7.13,对白色念珠菌的平均杀灭对数值为4.94.浓度为50 mg/L时,苯扎氯铵与十二烷基二亚丙三胺的抑菌环直径分别为8.3 mm和8.2 mm.结论 十二烷基二亚丙三胺的杀菌效果优于苯扎氯铵,抑菌效果无显著差异.

  10. Benzalkonium chloride (BAC) and dimethyldioctadecyl-ammonium bromide (DDAB), two common quaternary ammonium compounds, cause genotoxic effects in mammalian and plant cells at environmentally relevant concentrations.

    Science.gov (United States)

    Ferk, F; Misík, M; Hoelzl, C; Uhl, M; Fuerhacker, M; Grillitsch, B; Parzefall, W; Nersesyan, A; Micieta, K; Grummt, T; Ehrlich, V; Knasmüller, S

    2007-11-01

    Quaternary ammonium compounds (QACs) are cationic surfactants that are widely used as disinfectants. In the present study, we tested two important representatives, namely, benzalkonium chloride (BAC) and dimethyldioctadecyl-ammonium bromide (DDAB) in four genotoxicity tests, namely, in the Salmonella/microsome assay with strains TA 98, TA 100 and TA 102, in the single-cell gel electrophoresis (SCGE) assay with primary rat hepatocytes and in micronucleus (MN) assays with peripheral human lymphocytes and with root tip cells of Vicia faba. In the bacterial experiments, consistently negative results were obtained in the dose range between 0.001 and 110 microg per plate in the presence and absence of metabolic activation while significant induction of DNA migration was detected in the liver cells. With BAC, a moderate but significant effect was found with an exposure concentration of 1.0 mg/l while DDAB caused damage at lower doses (0.3 mg/l). The effects were not altered when the nuclei were treated with formamidopyridine glycosylase, indicating that they are not due to formation of oxidized purines. The MN assays with blood cells were carried out under identical conditions to the SCGE experiments and a significant increase was seen at the highest dose levels (BAC: 1.0 and 3.0 mg/l; DDAB: 1 mg/l). Both compounds also caused significant induction of MN as well as inhibition of cell division in plant cells, the lowest effective levels were 1.0 and 10 mg/l for DDAB and BAC, respectively. Our findings show that both chemicals induce moderate but significant genotoxic effects in eukaryotic cells at concentrations which are found in wastewaters and indicate that their release into the environment may cause genetic damage in exposed organisms. Furthermore, the direct contact of humans to QAC-containing detergents and pharmaceuticals that contain substantially higher concentrations than those which were required to cause effects in eukaryotic cells in the present study should

  11. Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system

    Directory of Open Access Journals (Sweden)

    Lovelace Cherie

    2011-04-01

    Full Text Available Abstract Background Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimicrobial performance of two commonly used topical ocular hypotensive agents that employ different preservative systems: latanoprost 0.005% with 0.02% BAK and travoprost 0.004% with sofZia, a proprietary ionic buffer system. Methods Each product was tested for antimicrobial effectiveness by European Pharmacopoeia A (EP-A standards, the most stringent standards of the three major compendia, which specify two early sampling time points (6 and 24 hours not required by the United States Pharmacopeia or Japanese Pharmacopoeia. Aliquots were inoculated with between 105 and 106 colony-forming units of the test organisms: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus brasiliensis. Sampling and enumeration were conducted at protocol-defined time points through 28 days. Results BAK-containing latanoprost met EP-A criteria by immediately reducing all bacterial challenge organisms to the test sensitivity and fungal challenges within the first six hours while the preservative activity of travoprost with sofZia did not. Complete bacterial reduction by travoprost with sofZia was not shown until seven days into the test, and fungal reduction never exceeded the requisite 2 logs during the 28-day test. Travoprost with sofZia also did not meet EP-B criteria due to its limited effectiveness against Staphylococcus aureus. Both products satisfied United States and Japanese pharmacopoeial criteria. Conclusions Latanoprost with 0

  12. In vitro cytotocity of Benzalkonium Chloride%苯扎氯铵对人结膜上皮细胞毒性的研究

    Institute of Scientific and Technical Information of China (English)

    刘扬; 刘祖国; 许传超; 陈小平; 李朝阳

    2008-01-01

    目的 探讨苯扎氯铵(BAC)对无血清培养法培养的人结膜上皮细胞的细胞毒性.方法 采用无血清培养的3-5代人结膜上皮细胞,将不同浓度的BAC(O.01%,0.005%,0.001%,0.0005%,0.0001%)单次作用于结膜上皮细胞15min,分别于处理细胞后6,12,24,48hMTT法检测细胞活力,于处理细胞后48h固定,扫描电镜观察拍照.结果 自BAC处理后6h起,与对照组相比,各浓度BAC均使细胞活力下降(P<0.01).经过48小时的恢复期,细胞活力未见恢复.随BAC浓度增高,细胞表面微绒毛消失,细胞出现不同程度收缩至脱落至大部分溶解坏死.结论 BAC对于培养的人结膜上皮细胞具有细胞毒性,其毒性作用呈剂量依赖性.%Objective To investigate the cytotoxic effects of benzalkonium chloride (BAC), a preservative used in many ophthalmic topical solutions, on human conjunctival epithelial cells in vitro.Methods Cultured epithelial cells obtained from human conjunctiva were exposed to medium containing BAC solutions at 0.01%, 0.005%, 0.001%, 0.0005% and 0.0001% concentrations for a period of 15 min. Cell were examined before treatment and 6,12, 24, 48 hours later, cell viability was assessed with methyl thiazolyl tetrazolium(MTT) assay, and scanning electron microscopy was used to evaluate the cytotoxic effect 48 hours after treatment.Results Cell viability decreased significantly in a dose-dependent manner after a single 15-minute treatment with BAC at various concentrations (P<0.01 at all points after treatment). Cells treated with BAC at different concentrations showed loss of micromilli, cell exfoliation, even death. Conclusions These results suggest that BAC induces cytotoxicity at a concentration as low as 0.0001%. The mode of BAC-induced cytotoxicity is dose-dependent.

  13. Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system

    Science.gov (United States)

    2011-01-01

    Background Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK) in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimicrobial performance of two commonly used topical ocular hypotensive agents that employ different preservative systems: latanoprost 0.005% with 0.02% BAK and travoprost 0.004% with sofZia, a proprietary ionic buffer system. Methods Each product was tested for antimicrobial effectiveness by European Pharmacopoeia A (EP-A) standards, the most stringent standards of the three major compendia, which specify two early sampling time points (6 and 24 hours) not required by the United States Pharmacopeia or Japanese Pharmacopoeia. Aliquots were inoculated with between 105 and 106 colony-forming units of the test organisms: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus brasiliensis. Sampling and enumeration were conducted at protocol-defined time points through 28 days. Results BAK-containing latanoprost met EP-A criteria by immediately reducing all bacterial challenge organisms to the test sensitivity and fungal challenges within the first six hours while the preservative activity of travoprost with sofZia did not. Complete bacterial reduction by travoprost with sofZia was not shown until seven days into the test, and fungal reduction never exceeded the requisite 2 logs during the 28-day test. Travoprost with sofZia also did not meet EP-B criteria due to its limited effectiveness against Staphylococcus aureus. Both products satisfied United States and Japanese pharmacopoeial criteria. Conclusions Latanoprost with 0.02% BAK exhibited more

  14. Cytotoxicity of five fluoroquinolone and two nonsteroidal anti-inflammatory benzalkonium chloride-free ophthalmic solutions in four corneoconjunctival cell lines

    Directory of Open Access Journals (Sweden)

    Masahiko Ayaki

    2010-09-01

    Full Text Available Masahiko Ayaki1, Atsuo Iwasawa2, Mitsutaka Soda3, Shigeo Yaguchi3, Ryohei Koide41Department of Ophthalmology, Saitama National Hospital, Saitama, Japan; 2Department of Clinical Pathology, Showa University Fujigaoka Hospital, Yokohama, Japan; 3Department of Ophthalmology, Showa University Fujigaoka Rehabilitation Hospital, Yokohama, Japan; 4Department of Ophthalmology, Showa University School of Medicine, Tokyo, JapanPurpose: Epithelial disorders after eye surgery can result in visual deterioration and patient discomfort. Such disorders may be caused by drug toxicity. In the present study, we evaluated the toxicity of ophthalmic solutions, with or without benzalkonium chloride (BAK as the preservative, used for postoperative care.Methods: A range of commercially available antibiotic and anti-inflammatory ophthalmic solutions used postoperatively (ie, levofloxacin, moxifloxacin, gatifloxacin, norfloxacin, tosufloxacin, dibekacin, cefmenoxime, diclofenac, bromfenac, pranoprofen, betamethasone, and fluoromethorone were assessed in three corneal cell lines and one conjunctival cell line. All antibiotic solutions were BAK free. Cell viability was determined with the 3-(4,5-dimethyl-2 thiazoyl-2,5-diphenyl-2H-tetrazolium bromide (MTT assay after cells had been exposed to the drugs for 48 h. The effects of preservatives on cell viability were also determined. Toxicity was compared using the cell viability score (CVS.Results: Based on results of the MTT assay and CVS, the order of cell viability after exposure to the antibiotic solutions was cefmenoxime ≥ tosufloxicin ≥ dibekacin ≥ levofloxacin ≥ norfloxacin = gatifloxacin = moxifloxacin. For the anti-inflammatory solutions, the order of cell viability was betamethasone ≥ betamethasone + fradiomycin > preservative-free diclofenac ≥ preservative-free bromfenac >> 0.02% fluoromethorone ≥ 0.1% fluoromethorone = diclofenac + preservative = bromfenac + preservative = pranoprofen. The anti

  15. Travoprost 0.004%/timolol 0.5%-fixed combination with and without benzalkonium chloride: a prospective, randomized, doubled-masked comparison of safety and efficacy

    Science.gov (United States)

    Kitazawa, Y; Smith, P; Sasaki, N; Kotake, S; Bae, K; Iwamoto, Y

    2011-01-01

    Purpose The purpose of this study is to compare the safety and intraocular pressure (IOP)-lowering efficacy of travoprost/timolol in a benzalkonium chloride (BAK)-free fixed combination preserved with polyquaternium-1 (TRA/TIM BAK-free), with travoprost/timolol-fixed combination preserved with BAK (TRA/TIM), in patients with open-angle glaucoma or ocular hypertension. Methods In this prospective randomized controlled trial, subjects with IOP of at least 22 mm Hg in one or both eyes at 0900 h, and IOP of at least 21 mm Hg in one or both eyes at 1100 h and 1600 h at two eligibility visits were randomly assigned to receive either TRA/TIM BAK-free (n=195) or TRA/TIM (n=193), dosed once daily in the morning (0900 h) for 6 weeks. IOP was assessed at 0900 h, 1100 h, and 1600 h at each scheduled visit (baseline, 2 and 6 weeks after randomization). Results Mean IOP reduction across all visits and time points was 8.0 mm Hg in the TRA/TIM BAK-free group and 8.4 mm Hg in the TRA/TIM group (P=0.0943). The difference in mean IOP between groups ranged from 0.2 to 0.7 mm Hg across visits and time points, with a mean pooled difference of 0.4 mm Hg (95% CI: −0.1 to 0.8), demonstrating equivalence of the two formulations. The most common drug-related adverse event was hyperemia of the eye (ocular hyperemia and conjunctival hyperemia combined), occurring in 11.8% of the TRA/TIM BAK-free group and 13.0% of the TRA/TIM group. Conclusion Travoprost/timolol BAK-free demonstrated equivalence to travoprost/timolol preserved with BAK in efficacy. No clinically relevant differences in the safety profiles of travoprost/timolol BAK-free and travoprost/timolol preserved with BAK were identified. PMID:21701528

  16. Determination of Benzalkonium Chloride in Besifloxacin Hydrochloride Eye Drops by HPLC%盐酸贝西沙星滴眼液中苯扎氯铵的HPLC法测定

    Institute of Scientific and Technical Information of China (English)

    陈再新; 朱峰; 王勇军

    2013-01-01

    An HPLC method was established for the determination of benzalkonium chloride in besifloxacin hydrochloride eye drops.A Kromasil C18 column was used,with the mobile phase of 5 mmol/L ammonium acetate (containing 1% triethylamine,adjust pH to 5.2±0.5 with glacial acetic acid)-acetonitrile (29 ∶ 71),at the detection wavelength of 215 nm.The flow rate was 1.0 ml/min.The calibration curve of benzalkonium chloride was linear in the concentration range of 5-15 μg/ml (R2=0.998 3).The average recovery was 99.4 % with RSD of 0.42 %.%建立了高效液相色谱法测定盐酸贝西沙星滴眼液中苯扎氯铵的含量.采用Kromasil C18柱,5 mmol/L乙酸铵溶液(含1%三乙胺,用冰乙酸调至pH 5.2±0.5)-乙腈(29∶71)为流动相,检测波长为215nm,流速1.0 ml/min.苯扎氯铵在5~15 μg/ml浓度范围内线性关系良好(R2=0.998 3),平均回收率为99.4% (RSD=-0.42%).

  17. Determination of Benzalkonium Chloride in Glutathione Eye Drops by HPLC%高效液相色谱法测定谷胱甘肽滴眼液中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    欧嘉娜

    2012-01-01

      Objective:To establish a HPLC method For the determination of Benzalkonium Chloride in Glutathione eye drops. Methods:The sample was analyzed on an Agilent Zorbax SB-CN column (4.6mm ×250mm,5μm) with mobile phase consisting of 0.1%phosphoric acid and acetonitrile and tetrahydrofuran (52∶38∶10) and the detection wavelength was 214nm. Results:The Calibration curves of Benzalkonium Chloride was linear in the range of 50~250μg/ml and the linear equation was Y=20674X-79747(r=0.99979). The average recoveries was 100.9% with RSD 0.19%. Conclusion :This method is simple, rapid, accurate and with good repeatability and recovery, it cab be used as a quality control method for this preparation.%  目的:建立测定谷胱甘肽滴眼液中苯扎氯铵含量的方法.方法:采用Agilent Zorbax SB-CN柱(4.6mm×250mm,5μm);流动相:0.1%磷酸水溶液-乙腈-四氢呋喃(52∶38∶10);检测波长:214nm.结果:苯扎氯铵的线性范围为50~250μg/ml,线性回归方程为Y=20674X-79747(r=0.99979).平均回收率分别为100.9%,RSD为0.19%.结论:该方法简便、快速、准确,具有良好的重复性和回收率,可作为该制剂的质量控制标准.

  18. Determination of Benzalkonium Chloride in Compound Aspartate, Vitamin B6 and Dipotassium Glycyrrhe-tate Eye Drops%复方门冬维甘滴眼液中苯扎氯铵的测定

    Institute of Scientific and Technical Information of China (English)

    董超琪

    2014-01-01

    目的::建立测定复方门冬维甘滴眼液中苯扎氯铵含量的方法。方法:采用Agilent Zorbax C18色谱柱(150 mm ×4.6 mm,5μm),以乙腈-5 mmol·L-1醋酸铵溶液(含1%三乙胺,用冰醋酸调节pH至5.0±0.5)(65∶35)为流动相,流速为1.0 ml·min-1,检测波长为214 nm。结果:苯扎氯铵在50.00~150.00μg·ml-1范围内与峰面积线性关系良好,r=0.9980;平均回收率为99.1%,RSD为0.6%。结论:该方法简便,迅速,灵敏度高,具有良好的重复性及回收率,可用于复方门冬维甘滴眼液中苯扎氯铵的测定。%Objective:To develop a method to determine benzalkonium chloride in compound aspartate, vitamin B6 and dipotassi-umglycyrrhetateeyedrops.Methods:TheseparationwasperformedonanAgilentZorbaxC18(150mm×4.6mm,5μm)column. The mobile phase consisted of acetonitrile-5 mmol·L-1 ammonium acetate ( in which 1% triethylamine was added, then the pH value was adjusted to 5. 0 ± 0. 5 by acetic acid) 65∶35(v/v). The flow rate was 1. 0 ml·min-1 and the detection wavelength was 214nm. Re-sults:Benzalkonium chloride had a good linearity within the range of 50. 00-150. 00μg·ml-1(r=0. 998 0), and the average recovery was 99. 1%(RSD=0. 6%). Conclusion:The method is simple, rapid and sensitive with good repeatability and recovery. It can be used to determine benzalkoinum chloride in compound aspartate, vitamin B6 and dipotassium glycyrrhetate eye drops.

  19. 苯扎氯铵溶液在慢性创面及感染肉芽肿的临床应用及观察%The Clinical Application and Observation of Benzalkonium Chloride used in Chronic Wound and Infectious Granuloma

    Institute of Scientific and Technical Information of China (English)

    王本峰; 张振信; 朱秀梅

    2014-01-01

    Objective:To observe the benzalkonium chloride disinfectant on sterilization of chronic wound infection and promote healing. Methods: we used Benzalkonium chloride disinfectant in Chronic wounds and granuloma after debridement,and then observe the sterilization ef ect of Staphylococcus aureus,bacil us,Acinetobacter bactericidal action Escherichia coli that is drug resistant. Results: 0.1% benzalkonium chloride solution has obvious ef ect on kil ing high resistant bacteria from chronic wound and infectious granuloma and educeing scar formation obviously. Conclusion:0.1% benzalkonium chloride solution has obvious ef ect on kil ing high resistant bacteria from chronic wound and infectious granuloma,Short ing the time of wound healing and improving the quality of wound healing.%目的:观察苯扎氯铵消毒液对慢性感染性创面的杀菌及促使修复作用。方法对慢性创面及感染性肉芽肿扩创后外用苯扎氯铵消毒液,观察其对耐药的金黄色葡萄球菌、不动杆菌、大肠埃希菌的灭菌作用。结果0.1%苯扎氯铵溶液对慢性创面及感染性肉芽肿的高耐药细菌有明显的灭菌、减少瘢痕形成。结论0.1%苯扎氯铵溶液对慢性创面及感染性肉芽肿的高耐药细菌有明显的灭菌,缩短创面愈合时间,提高创面愈合质量。

  20. Biofilm matrix composition affects the susceptibility of food associated staphylococci to cleaning and disinfection agents

    Directory of Open Access Journals (Sweden)

    Annette eFagerlund

    2016-06-01

    Full Text Available Staphylococci are frequently isolated from food processing environments, and it has been speculated whether survival after cleaning and disinfection with benzalkonium chloride-containing disinfectants is due to biofilm formation, matrix composition or benzalkonium chloride efflux mechanisms. Out of 35 food associated staphylococci, eight produced biofilm in a microtiter plate assay and were identified as Staphylococcus capitis (2, S. cohnii, S. epidermidis, S. lentus (2, and S. saprophyticus (2. The eight biofilm producing strains were characterized using whole genome sequencing. Three of these strains contained the ica operon responsible for production of a polysaccharide matrix, and formed a biofilm which was detached upon exposure to the polysaccharide degrading enzyme Dispersin B, but not Proteinase K or trypsin. These strains were more tolerant to the lethal effect of benzalkonium chloride both in suspension and biofilm than the remaining five biofilm producing strains. The five benzalkonium chloride susceptible strains were characterized by lack of the ica operon, and their biofilms were detached by Proteinase K or trypsin, but not Dispersin B, indicating that proteins were major structural components of their biofilm matrix. Several novel cell wall anchored repeat domain proteins with domain structures similar to that of MSCRAMM adhesins were identified in the genomes of these strains, potentially representing novel mechanisms of ica-independent biofilm accumulation. Biofilms from all strains showed similar levels of detachment after exposure to alkaline chlorine, which is used for cleaning in the food industry. Strains with qac genes encoding benzalkonium chloride efflux pumps could grow at higher concentrations of benzalkonium chloride than strains without these genes, but no differences were observed at biocidal concentrations. In conclusion, the biofilm matrix of food associated staphylococci varies with respect to protein or

  1. Determination of Benzalkonium Chloride Homologs in Complex Chemical Disinfectant by High-Performance Liquid Chromatography%复方化学消毒剂中苯扎氯铵的高效液相色谱测定

    Institute of Scientific and Technical Information of China (English)

    刘雯雯; 张瑾; 乔俊琴; 练鸿振

    2011-01-01

    建立了一种测定复方化学消毒剂中苯扎氯铵成分十二烷基二甲基苄基氯化铵、十四烷基二甲基苄基氯化铵和十六烷基二甲基苄基氯化铵的反相离子对高效液相色谱法.色谱柱为Platisil ODS(5 μm,250 mm×4.6 mm),流动相为甲醇-0.2 mol/L己烷磺酸钠(含1%三乙胺,V/V,用高氯酸调节至pH=6.0,体积比85∶15),紫外220 nm检测.用己烷磺酸钠作为离子对试剂,增强了苯扎氯铵成分的保留,三乙胺作为扫尾剂,通过抑制固定相表面残存的硅羟基对苯扎氯铵成分的吸附,减少了色谱峰拖尾.3种苯扎氯铵成分分离良好,标准曲线的线性范围分别为0.002~5 mg/mL、0.005~10 mg/mL和0.005~10 mg/mL,检测限分别为0.0005 mg/mL、0.001 mg/mL和0.001 mg/mL.方法具有良好的准确度和精密度,在测定低浓度样品时优势明显.实际用于测定苯扎氯铵消毒液和医用消毒纸巾中3种苯扎氯铵成分的含量,回收率为99.3%~104.1%,日内和日间测定相对标准偏差(RSD)均小于2.0%.%An ion pair reversed phase High-Performance Liquid Chromatography ( HPLC ) method has been developed for the simultaneous determination of benzalkonium chloride ( BAC ) homologues, dodecyl dimethyl benzyl ammonium chloride ( C12 ), tetradecyl dimethyl benzyl ammonium chloride ( C14 ) and cetyl dimethyl benzyl ammonium chloride ( C16 ), in complex chemical disinfectant. Separation was carried out on Platisil ODS column ( 5 μm, 250 mm ×4. 6 mm ), using methanol and 200 mmol/L hexane sulfonate sodium aqueous solution consisting of 1 % triethylamine ( V/V), adjusted with perchloric acid to pH 6. 0 ( 85 : 15, V/V) as the mobile phase in an isocratic elution. The detection wavelength was 220 nm. In the experiment, sodium hexanesulfonate was used as the ion-pair reagent to enhance the retention of benzalkonium chloride, and triethylamine was used as the tailing-suppressor to restrain the adsorption of benzalkonium chloride to the residual silanols

  2. Antibiotic Washing Therapy of Maxillofacial Abscess: Comparison of Benzalkonium Chloride versus Povidone Iodine%苯扎氯铵溶液与碘伏溶液冲洗治疗颌面部脓肿疗效比较

    Institute of Scientific and Technical Information of China (English)

    王建国; 李可来; 李庆隆

    2013-01-01

    Objectives:To compare the treatment efficacy of benzalkonium chloride solution versus povidone iodine solution in maxillofacial abscess washing therapy.Methods:59 cases of maxillofacial abscess patients were randomly divided into experiment group A (29 cases) and comparative group B (30 cases).In group A,maxillofacial abscess was partly incised and drainged,then rinsed daily with 0.01% benzalkonium chloride solution.In group B,patients' abscess partly incised and drainged,then rinsed daily with 0.25% povidone iodine solution.In both groups,bacterial culture of the pus were undertaken before incision and drainage and every 3 days after washing therapy.Results:Three days after dressing,the positive rate of bacterial culture in experimental group A and comparative group B were 7 cases and 15 cases respectively.6 days after,positive culture cases were 0 in group A and 7 in group B.The average dressing time in experimental group A and comparative group B were 3.34 days and 5.87 days respectively.Conclusion:The treatment efficiency of abscess by benzalkonium chloride solution is much better than by povidone iodine solution.%目的:对比苯扎氯铵溶液及碘伏溶液在冲洗治疗颌面部脓肿中的效果.方法:颌面部脓肿患者59例,随机分为实验组29例,对照组30例.实验组行脓肿切开引流后每天用0.01%苯扎氯铵溶液冲洗;对照组行脓肿切开引流后每天用0.25%碘伏溶液冲洗.两组病例均在脓肿切开前取脓液送细菌培养,切开后每3d取脓液送细菌培养1次.并记录每例患者治愈脓肿的换药天数.结果:换药3d后实验组细菌培养阳性为7例,对照组细菌培养阳性为15例;换药6d后实验组细菌培养阳性为0例,对照组细菌培养阳性为7例.实验组平均换药天数为3.34 d,对照组平均换药天数为5.87d.结论:用苯扎氯胺溶液冲洗治疗颌面部脓肿比用碘伏溶液冲洗更为有效,并可以减少脓肿切开后到治愈的换药天数.

  3. 苯扎氯铵溶液用于烧伤创面的初步临床观察%Preliminary Clinical Observation of Benzalkonium Chloride on Burn Wounds

    Institute of Scientific and Technical Information of China (English)

    李峰; 柴家科; 杨红明

    2012-01-01

    目的 观察苯扎氯铵溶液对烧伤创面的抑菌作用及对创面愈合的影响.方法 2007年10月-2008年8月共观察30名成年住院烧伤患者,按自身对照分别使用苯扎氯铵和碘伏溶液换药,在第1、第7天换药前行细菌培养观察长期抑菌作用;10例在消毒后3 min再次行细菌培养,观察其即时消毒效果;第7天观察创面愈合率.结果 苯扎氯铵组和碘伏组的长期、即时抑菌作用基本类似,用药第7天创面愈合率苯扎氯铵组高于碘伏组,差异有统计学意义.两组在换药时患者感觉均有疼痛感,未见伤口周围皮肤瘙痒和皮疹.结论 苯扎氯铵溶液用于烧伤创面的抑菌作用与碘伏类似,但是苯扎氯铵溶液是阳离子表面活性剂,可清洁创面血污及有机物,有利于创面愈合,有可能替代碘伏成为烧伤创面基本用药.%Objective To observe the bacteriostasis of benzalkonium chloride solution(BZK) on bum wounds. Methods From October 2007 to August 2008 in our hospital,30 adult burned patients were enrolled in the study. BZK or povidone iodine ( PVP-iodine) were used on the wounds by self-control. Wounds culture was performed on the 1st and 7 th day before dressing exchange to observe the long term bacteriostasis. In order to observe the immediate bacteriostasis, wounds bacterial culture were conducted 3 min later after the disinfection was performed in 10 of them. The healing rate was observed on the 7th day. Results The long term or immediate bacteriostasis was similarly, however, the wounds healing rate in BZK group was significantly higher than that PVP-iodine group. The patients in both groups felt pain when dressed; there was no itching or rashes of the skin around the wound. Conclusion Benzalkonium chloride solution has a similar bacteriostasis for burn wounds with povidone-iodine. Benzalkonium chloride solution is also a cationic surface active agent,it can clean the wounds bloodstained and organic matter,is conducive to

  4. 高效液相色谱法同时测定化妆品中的3种苯扎氯铵同系物%Simultaneous determination of 3 benzalkonium chloride homologsin cosmetics by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    刘艳琴; 王浩; 杨红梅; 史海良; 郭启雷

    2011-01-01

    建立了采用高效液相色谱-二极管阵列检测器(HPLC-DAD)同时检测化妆品中3种苯扎氯铵同系物(n-CH-CHNCl、n-CH-CHNCl、n-CH-CHNCl)的方法.采用含0.5%甲酸的甲醇超声提取样品,以CAPCELL PAK SCX色谱柱(250 mm×4.6 mm,5 μm)分离,流动相为40 mmol/L乙酸铵水溶液(含0.1%三乙胺,pH 4.0)和乙腈,梯度洗脱,流速1.0 mL/min,检测波长260 nm,柱温25℃,进样量20 μL.该方法的检出限50.0 mg/kg,定量限200.0 mg/kg,线性范围5.0~3 000.0 mg/L,加标回收率92.5%~102.1%.相对标准偏差为3.81%~6.66%.结果表明,该方法快速、准确,能够同时测定化妆品中3种苯扎氯铵同系物.%An analytical method based on high performance liquid chromatography with a diode array detector (HPLC-DAD) has been established for the simultaneous determination of 3 benzalkonium chloride homologs (n-C12H25-C9H13NCl, n-C14H29-C9H13NCI, n-C16H33-C9H13NCl) in cosmetics.The sample was extracted with methanol ( including 0.5% formic acid) under ultrasonic operation, the HPLC separation was carried out on a CAPCELL PAK SCX column (250 mm × 4.6 mm, 5 μm), the mobile phases were 40 mmol/L ammonium acetate solution (including 0.1% triethylamine) and acetonitrile with gradient elution, the flow rate was 1.0 mL/min, the detection wavelength was 260 nm, the column temperature was 25 ℃, and the injection volume was 20 μL.The limit of detection was 50.0 mg/kg and the quantitation limit was 200.0 mg/kg for 3 benzalkonium chloride homologs in cosmetics.The linear plots were obtained between 5.0 mg/L and 3 000.0 mg/L.Overall recoveries were between 92.5% and 102.1% with the relative standard deviations (RSDs) between 3.81% and 6.66%.The method is simple, rapid, accurate and suitable for the determination of 3 benzalkonium chloride homologs in cosmetics.

  5. HPLC法测定磷酸钠盐灌肠液中防腐剂苯扎氯铵的含量%Deternination of Preservative Benzalkonium Chloride in Sodium Phos-phate Rectal Solution by HPLC

    Institute of Scientific and Technical Information of China (English)

    傅素华; 叶兴法; 韩鹏; 田利洪

    2015-01-01

    目的:建立测定磷酸钠盐灌肠液中防腐剂苯扎氯铵的含量。方法采用高效液相色谱法。色谱柱为 Ultimate AQ-C18柱(5μm,4.6×250mm);流动相:乙腈-5mmoL醋酸铵溶液(含1%三乙胺,用冰醋酸调节pH值至5.0±0.5)(65∶35);流速:1.0mL· min -1;柱温:35℃;检测波长214nm。结果苯扎氯铵n-C12H25取代同系物在0.1839μg~0.5517μg范围内线性关系良好。(r=0.9999,n =5);平均回收率为100.5%, RSD为1.45%(n=9)。结论该方法简便快速,结果准确,可用于测定磷酸钠盐灌肠液中防腐剂苯扎氯铵的含量。%OBJECTIVE To establish a method for the the Deternination of preservative benzalkonium chloride in Sodium Phosphate Rectal Solution.METHODS HPLC, Liquid chromatography column was Ultimate AQ-C18 (5μm,4.6 ×250mm);mobile phase was acetonitrile-5mmol· L-1 ammonium acetate solution (Containing 1%three triethylamine;dilute Glacial aceticacld pH 5.0 ±0.5 ) ( 65∶35 );flow rate was 1.0 mL · min-1;column temperature was 35℃;detection wavelength was 214 nm.RESULTS The calibration curve of n-C12 H2 5 substituted congeners in benzalkonium chloride was linear in the sample volume range of 0.1839μg~0.5517μg ( r=0.9999 ).The average recovery was 100.5%(RSD=1.45%,n=9).CONCLUSION The method is simple,rapid and accurate,can be the product quality control methods.

  6. Determination of Benzalkonium Chloride in Loteprednol and Tobramycin Ophthalmic Suspension by HPLC%高效液相色谱法测定复方混悬滴眼液中苯扎氯铵含量

    Institute of Scientific and Technical Information of China (English)

    杨龙华; 宿洁; 陈涛; 卢京光

    2016-01-01

    Objective To establish an HPLC method for the determination of benzalkonium chloride in Loteprednol and Tobramycin Ophthalmic Suspension. Methods After being filtrated,samples were separated by HPLC on a Waters Spherisorb S5 CN column(250 mm × 4. 6 mm,5 μm). The mobile phase was 0. 1% phosphoric acid water solution- acetonitrile- tetrahydrofuran(52 :39 :15). The detec-tion wavelength was 216 nm. The flowing speed was 1. 5 mL/min. The column temperature was 30 ℃. Results The mass concentration of benzalkonium chloride was in good linear relationship with the peak area in the range of 0. 04-0. 20 g/L ( r=0. 999 9,n=5), and the average recovery rate was 100. 22%,RSD=0. 59%( n=9). Conclusion The method is sensitive,accurate and convenient with good resolution,it can be applied to control the quality of Loteprednol and Tobramycin Ophthalmic Suspension.%目的:建立测定氯替泼诺妥布霉素复方混悬滴眼液中防腐剂苯扎氯铵含量的高效液相色谱(HPLC)法。方法色谱柱为Waters Spherisorb S5 CN柱(250 mm ×4.6 mm,5μm),流动相为0.1%磷酸溶液-乙腈-四氢呋喃(52:39:15),流速为1.5 mL/min,检测波长为216 nm,柱温为30℃。结果苯扎氯铵质量浓度在0.04~0.20 g/L( r=0.9999,n=5)范围内与峰面积线性关系良好,平均回收率为100.22%,RSD为0.59%( n=9)。结论该方法简便、灵敏,色谱峰分离度良好,结果准确、可靠,可用于氯替泼诺妥布霉素混悬滴眼液的质量控制。

  7. Determination of benzalkonium chloride in ambroxol hydrochloride inhalation solution by RP-HPLC%反相液相色谱法测定盐酸氨溴素吸入溶液中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    卜宇倩; 蒋宇丹; 邵佶祥

    2015-01-01

    目的:建立盐酸氨溴素吸入溶液中苯扎氯铵含量的反相液相色谱测定方法。方法:采用Agilent Zorbax SB-C18色谱柱(4.6 mm×250 mm,5mm);以0.02 mol/L庚烷磺酸钠(含0.1%三乙胺,用磷酸调节pH至3.0±0.1)-乙腈(35∶65)为流动相;检测波长208 nm;进样体积20ml。结果:苯扎氯铵浓度在3.32~7.74mg/ml范围内线性关系良好,平均回收率为99.2%。结论:该方法快速、简便、准确、专属性强、重复性好,可适用于盐酸氨溴索吸入溶液中苯扎氯铵的含量测定。%Objective:To establish a RP-HPLC method for the quantitative analysis of benzalkonium chloride in ambroxol hydrochloride inhalation solution.Methods: RP-HPLC was performed on a column of an Agilent Zorbax SB- C18 (4.6 mm × 250 mm,5mm) with a mobile phase of 0.02 mol/L sodium 1-heptanesulfate solution (containing 0.1% triethylamine, adjusted pH to 3.0±0.1 by phosphate)-acetonitrile (35∶65) and at UV detection wavelength of 208 nm. Results:The standard curve was linear over the range of 3.32~7.74mg/ml with the average recovery 99.2% (n=9).Conclusion:This method is fast, simple, accurate, sensitive with good reproducibility and can be applied in the determination of benzalkonium chloride in ambroxol hydrochloride inhalation solution.

  8. 高效液相色谱法测定消毒湿巾中苯扎氯铵的含量%HPLC Determination of Benzalkonium Chloride in Disinfectant Wet Wipes

    Institute of Scientific and Technical Information of China (English)

    黄银波; 李兴根; 乔勇升; 胡慧

    2012-01-01

    A method for determination of benzalkonium chloride in disinfectant wet wipes by HPLC was proposed. The sample was extracted ultrasonically with the mobile phase, and then separated on Eclipse XDB-C18 (150 min×4. 6 mm, 5 μm) column, using a mixture of acetonitrile and 70 mmol · L^-1 ammonium acetate solution (containing 1% by vol. of triethylamine, adjusted with acetic acid to pH 5.0) in the ratio of 70 to 30 as mobile phase. Photodiode array detections were made at 262 nm. Linear relationships between values of peak areas and mass concentration of benzalkonium chloride was obtained in the range of 100--500 mg· L^-1 ,with limit of detection (3S/N) of 10. 2 mg · L^-1. The proposed method was used in the analysis of sample of disinfectant wet wipes, values of recovery found by standard addition method were in range of 95.3%-97.8% with RSD's (n=5) in the range of 2.5 %- 4.0%.%提出了高效液相色谱法测定消毒湿巾中苯扎氯铵含量的方法。样品经流动相超声提取,以Eclipse XDB-C18色谱柱(150 mm×4.6 mm,5μm)为分离柱,以乙腈-70 mmol.L-1乙酸铵(含1%三乙胺,冰乙酸调pH至5.0)按体积比70比30混合液为流动相,用二极管阵列检测器于波长262 nm处测定。苯扎氯铵的质量浓度在100~500 mg.L-1范围内与其峰面积呈线性关系,检出限(3S/N)为10.2mg.L-1。应用此法测定消毒湿巾中苯扎氯铵,回收率在95.3%~97.8%之间,相对标准偏差(n=5)在2.5%~4.0%之间。

  9. Paradoxical bronchospasm from benzalkonium chloride (BAC) preservative in albuterol nebulizer solution in a patient with acute severe asthma. A case report and literature review of airway effects of BAC.

    Science.gov (United States)

    George, Mathew; Joshi, Saumya Vinod; Concepcion, Emily; Lee, Haesoon

    2017-01-01

    Nebulized bronchodilator solutions are available in the United States as both nonsterile and sterile-filled products. Sulfites, benzalkonium chloride (BAC), or chlorobutanol are added to nonsterile products to prevent bacterial growth. Bronchoconstriction from inhaled BAC is cumulative, prolonged, and correlates directly with basal airway responsiveness. The multi-dose dropper bottle of albuterol sulfate solution contains 50 μg BAC per/2.5 mg of albuterol, which may be below or at the lower limit of the threshold dose for bronchoconstriction. However, with repeated albuterol nebulization, the effect can be additive and cumulative, often exceeding the bronchoconstriction threshold. We report a case of a 17 years old patient, who received 32 mg of BAC via nebulization over a period of 3.5 days that probably caused persistent bronchospasm evidenced by failure to improve clinically and to increase peak expiratory flow rate (PEFR) from 125 L/min (27% of predicted value) to 300 L/min (68% of predicted value) within 2 hours of withdrawing BAC. The patient's respiratory status and PEFR improved dramatically once the nebulization solution was switched to BAC free lev-albuterol solution. The pediatric providers, particularly the emergency department physicians, intensivists and pulmonologists need to be aware of this rare albeit possible toxicity to the respiratory system caused by BAC used as a preservative in albuterol nebulizer solution.

  10. Ocular Inflammation and Corneal Permeability Alteration by Benzalkonium Chloride in Rats: A Protective Effect of a Myosin Light Chain Kinase Inhibitor

    Science.gov (United States)

    Droy-Lefaix, Marie Thérèse; Bueno, Lionel; Caron, Philippe; Belot, Eric; Roche, Olivier

    2013-01-01

    Purpose. The aim of this study was to evaluate the interest of an ophthalmic eyedrop preparation containing a myosin light chain kinase (MLCK) inhibitor, ML-7, in the treatment of ocular surface. The local protective effect on the inflammation and the increase of corneal permeability induced by benzalkonium (BAK) was evaluated. Methods. An ocular instillation of 10 μL BAK at a concentration of 0.1% in PBS was performed on rats. The eyes were rinsed with sterilized water, 10 minutes after BAK preceded by instillation at T −24, −12, and −0.5 hours of 10 μL of ML-7: 100 μg (10 μL) into a gel form vehicle. All animals were sacrificed 6 hours after BAK instillation. The eyes were isolated for study in a masked manner. The ocular surface inflammation was assessed by measuring the inflammatory cell infiltration by a histologic quantitative analysis and for total ocular myeloperoxidase (MPO) activity. The tight junction permeability was tested. Results. Instillation of 0.1% BAK increased the inflammation of the eye. The quantitative analysis showed an increase in the number of eosinophil and neutrophil polynuclears, and MPO activity. Pretreatment with ML-7 reduced inflammation (P < 0.05). The vehicle alone produced no notable effects. BAK instillation also thickened the fluorescent corneal front on frozen sections, indicating an increase of tight junction permeability. Pretreatment with ML-7 suppressed BAK-induced alterations of paracellular permeability while the vehicle had no visible effects. Conclusions. Our study indicates that the inhibition of corneal cytoskeleton contraction by an MLCK inhibitor prevents BAK-induced ocular inflammatory response, and that ML-7 may be a new and original preparation in the treatment of ocular surface pathologies. PMID:23518768

  11. 苯扎氯铵对食管下端肌间神经毁损效果的研究%The effect of benzalkonium chloride in the damage of the myenteric plexus of lower esophagus in rats

    Institute of Scientific and Technical Information of China (English)

    赵艳民; 梁振; 李仲荣; 朱利斌; 刘征吉; 陈肖鸣

    2009-01-01

    目的 观察苯扎氯铵(BAC)毁损食管下端括约肌肌间神经的效果及毁损后不同时间神经组织的改变,为建立合适的贲门失迟缓症动物模型奠定基础.方法 80只健康的雄性SD大鼠随机分为二组:BAC组和生理盐水对照组各40只;开腹手术将0.4%BAC脑棉敷于大鼠食管下端30 min,术后1、2、4、8周分别处死大鼠,观察食管下端肌间神经组织的变化.结果 术后1周BAC组食管下端出现部分肌间神经元、神经纤维变性坏死;术后第二周肌间神经元密度为(1.25±1.58)个/横切面,与对照组(5.38±2.33)个/横切面相比,明显减少(P<0.01);术后4周和术后8周肌间神经元进一步减少,但这种减少与术后第二周的差异无统计学意义(P>0.05).BAC对不同神经递质的神经元毁损为非选择性的.结论 0.4BAC能成功毁损大鼠食管下端肌间神经元,肌间神经元毁损的动物玎丁用于贲门失弛缓症实验研究.%Objective To establish the appropriate animal model of achalasia in the cardia and to observe the effect of Benzalkonium Chloride(BAC) in the damag of the myenteric plexus of lower esophagus in rats and the changes of neurons at different time points.Methods Eighty male SD rats were randomly divided into two experimental groups (40 rats respectively in the BAC group and control groups).The 0.4% benzalkonium chloride was applied on the lower esophagus for 30 minutes during the laparotomy on rats.The changes of the neuron in lower esophagus were observed under microscope after sacrifice of rats at 1,2,4 and 8 weeks respectively.Results One week after the operation,degeneration and necrosis were observed in parts of the neurons and the nerve fibers in the myenteric plexus of lower esophagus in the BAc group.Two weeks after the operation,density of neurons in BAC group was 1.25±0.71 neurons per cross section,which was significantly lower than that in the control group (5.38±2.33 neurons per cross section

  12. The effect of chloride fertilization on blackspot susceptibility and other quality characteristics and on yield of potato

    NARCIS (Netherlands)

    Loon, van C.D.; Berg, van den W.

    2004-01-01

    Trials were carried out in two years on a sandy loam and on a heavy clay soil with two cultivars to examine the potential of chloride fertilization as a tool to reduce blackspot susceptibility of potatoes and to investigate other effects on yield and quality. Blackspot susceptibility was significant

  13. 高效液相色谱法测定化妆品中苯扎氯铵%Determination of benzalkonium chloride in cosmetics by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    张鹏祥; 曹蕊; 高晓譞; 尹家振; 张明明; 赵华

    2012-01-01

    采用高效液相色谱法测定化妆品中苯扎氯铵的含量.色谱条件为:Agilent Zorbax CN柱(250 mm×4.6 mm i.d.,5μm),流动相为V(乙腈)∶V(0.1 mol· L-1醋酸铵缓冲溶液(冰醋酸调pH =5.0))=70∶30的混合溶液,流速1.0 mL·min-1,检测波长260 nm,柱温25℃,进样量20 μL.结果表明,该方法的检出限为130μg·g-1,线性范围为5~100 mg ·L-1,回收率为92.0%~110.6%,RSD为0.32%~2.10%.%A high performance liquid chromatographic method was established for the determination of benzalkonium chloride in cosmetics. Chromatography separation was carried out on a Agilent Zorbax CN column (250 mm × 4. 6 mm i. d. ,5 μm), using acetonitrile with 0. 1 mol · L-1 ammonium acetate (70: 30 volume ratio and pH adjusted to 5.0 by glacial acetic acid) as mobile phase. The flow rate was 1.0 mL · min-1 and the column temperature was 25℃. Detection was carried out at 260 nm. The limit of detection is 130 μg · g-1. Linear plot ranges between 5 ~ 100 mg · L-1. Average recoveries are 92.0% -110.6% with relative standard deviations of 0. 32% ~2. 10%.

  14. Ultrastructural effects of acetone and benzalkonium chloride on the stratum corneum lipids in murine epidermis%丙酮和氯化苯甲烃铵对角质层脂质超微结构的影响

    Institute of Scientific and Technical Information of China (English)

    姜少军; 周晓军

    2003-01-01

    本文用裸鼠作为实验动物对化学刺激性物质导致角质层脂态的变化进行超微结构的研究.裸鼠表皮经丙酮和氯化苯甲烃铵处理后,样品用四氧化钌固定.超微结构观察表明由于丙酮和氯化苯甲烃铵的刺激作用导致角质层脂质形态的变化、角质层脂质的抽提以及在角质细胞之间形成腔隙.结果表明四氧化钌对角质层脂质有良好的固定作用,并清晰地展示出丙酮和氯化苯甲烃铵对角质层脂质的影响.%To gain a better understanding of the interaction of chemically different irritants with the stratum corneum lipids, the morphological changes of the stratum corneum lipids resulting from the chemical irritants in murine epidermis were investigated. Node mice were treated topically with either acetone or 2% benzalkonium chloride, the visualization of the stratum corneum was carried out using a special fixation method utilizing 0.25% ruthenium tetroxide as the post-fixative. Ultrastructural observation demonstrated obvious distortions within the intercellular domains of the stratum corneum, including disorganization of lipid bilayers, lipid extraction, and lacunae formation. The results of this study indicated that ruthenium tetroxide is a preferable post-fixative for the study of the stratum corneum lipids, and provide evidence that different irritants induce distinct alterations within the stratum corneum to reflect the specific interaction with the stratum corneum lipids.

  15. [The influence of an isotonic solution containing benzalkonium chloride and a hypertonic seawater solution on the function of ciliary epithelium from the nasal cavity in vitro].

    Science.gov (United States)

    Laberko, E L; Bogomil'sky, M R; Soldatsky, Yu L; Pogosova, I E

    2016-01-01

    The objective of the present study was to evaluate the influence of an isotonic saline solution containing benzalconium chloride and of a hypertonic seawater solution on the function of ciliary epithelium in the nasal cavity in vitro. To this effect, we investigated the cytological material obtained from 35 children presenting with adenoid tissue hypertrophy. The tissue samples were taken from the nasal cavity by the standard method. A cellular biopsy obtained from each patient was distributed between three tubes that contained isotonic saline solution supplemented by benzalconium chloride (0.1 mg/ml), a hypertonic seawater solution, and a standard physiological saline solution. It was shown that the number of the viable cells in both isotonic solutions was statistically comparable and significantly higher than in the hypertonic solution (p<0.05). The ciliary beat frequency of the cells embedded in the two isotonic solutions was not significantly different but considerably exceeded that in the hypertonic seawater solution (p<0.05). Thus, the present study has demonstrated the absence of the ciliotoxic influence of isotonic saline solution containing benzalconium chloride at a concentration of 0.1 mg/ml and the strong ciliotoxic effect of the hypertonic seawater solution. This finding gives reason to recommend isotonic solutions for the regular application whereas hypertonic solutions can be prescribed only during infectious and/or inflammatory ENT diseases.

  16. 高效液相色谱法测定重组人干扰素α1b滴眼液中苯扎氯铵的含量%Determination of benzalkonium chloride content in recombinant human interferon a1b eye drops by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    牛晓霞; 曹艳; 吴美英

    2013-01-01

    Objective To determine the benzalkonium chloride content in recombinant human interferon α1b (rhIFNα1b) eye drops by high performance liquid chromatography (HPLC).Methods The benzalkonium chloride content in rhIFNα1b eye drops was determined by HPLC.A Waters Symmetry C18 column was used with the mobile phase of V(A):V(B) =65:35 [A:acetonitrile; B:5 mmol/L ammonium acetate containing 1% triethylamine,adjusted with acetic acid to pH(5.0 ± 0.2)] at a flow rate of 1.0 ml/min.The detection wavelength,sample load and column temperature were 262 nm,20 μl and room temperature,respectively.The method was verified,and used for determination of benzalkonium chloride contents in three batches of rhIFNα1b eye drops.Results The method showed good specificity and suitability in determination of benzalkonium chloride content,of which the minimum detection limit and minimum quantitation limit were 0.53 and 1.48 μg/ml respectively.The standard curve showed good linearity within a benzlkonium chloride concentration range of 10 ~ 50 μg/ml (R2 =0.9991).The RSD of peak areas of six samples loaded were 1.78%.The mean recovery rate of samples at theoretical benzalkonium chloride concentrations of 22,24 and 26 μg/ml was 97.90%,with a RSD of 0.96%.The relative benzalkonium chloride contents in three batches of rIFNα1b eye drops were 19.27,19.89 and 19.76 μg/ml,which were 96.34%,94.46% and 98.80% of stated amounts,respectively.Conclusion The developed HPLC method was simple,sensitive and accurate,which might be used for determinatioin of benzalkonium chloride content in recombinant human interferon α1b eye drops.%目的 采用高效液相色谱法(high performance liquid chromatography,HPLC)测定重组人干扰素α1b(recombinant human interferon α1b,rhIFNα1b)滴眼液中苯扎氯铵(benzalkonium chloride)的含量.方法 采用HPLC法测定rhIFNα1b滴眼液中苯扎氯铵含量,色谱条件:流动相:乙腈:5 mmol/L醋酸铵[含1%三乙胺

  17. Clinical Observation of Benzalkonium Chloride and Povidone-Iodine in Treatment of 56 Cases with Large Area of Skin Defect and Infection in Limbs%苯扎氯铵与碘伏治疗肢体大面积皮肤缺损并感染56例临床观察

    Institute of Scientific and Technical Information of China (English)

    孙鲁; 刘恒平; 王明喜

    2012-01-01

    Objective To observe the effect of benzalkonium chloride and povidone-iodine in the treatment of patients with large area of skin defect and infection in limbs. Methods Total 56 cases with large area of skin defects and infection in limbs in our hospital from September 2008 to November 2010 were randomly divided into two groups. After the debridement surgery and skin flap or skin graft surgery, benzalkonium chloride and povidone-iodine irrigation treatment were performed, the efficacy of two disinfectants and local adverse reactions were observed. Results The total effective rate was 96. 43% in the benzalkonium chloride group and 85. 71% in the povidone-iodine group. The growth of granulation,elongation of skin,effect of internal fixation materials on wound and the incidence of complication in the benzalkonium chloride group were better as compared to the povidone-iodine group. There was statistically significance,P <0. 05. Conclusion The benzalkonium chloride can accelerate wound healing, it has a strong bactericidal control on the local infection, and has non-irritating to the skin. It is the first choice for the treatment of antibacterial drugs for clinical disinfection.%目的 观察苯扎氯铵与碘伏治疗肢体大面积皮肤缺损并感染的效果.方法 将我院收治的56例肢体大面积皮肤缺损并感染患者随机分为两组,在清创手术及皮瓣转移术或皮肤移植术后分别采用苯扎氯铵与碘伏冲洗治疗,观察两种消毒剂的疗效、并发症、肉芽生长速度、皮肤爬行速度及内固定材料对创面的影响.结果 苯扎氯铵组总有效率96.43%,碘伏组总有效率为85.71%,苯扎氯铵组的肉芽生长速度、皮肤爬行速度、内固定材料对创面的影响、并发症发生率方面均明显优于碘伏组,上述指标组间差异均具有统计学意义(P值均<0.05).结论 苯扎氯铵能加速创面的愈合,有较强的杀菌、控制局部感染作用,且对皮肤无刺激性,临床

  18. Age-dependent susceptibility to phenobarbital-resistant neonatal seizures: role of chloride co-transporters

    Directory of Open Access Journals (Sweden)

    Seok Kyu eKang

    2015-05-01

    Full Text Available Ischemia in the immature brain is an important cause of neonatal seizures. Temporal evolution of acquired neonatal seizures and their response to anticonvulsants are of great interest, given the unreliability of the clinical correlates and poor efficacy of first-line anti-seizure drugs. The expression and function of the electroneutral chloride co-transporters KCC2 and NKCC1 influence the anti-seizure efficacy of GABAA-agonists. To investigate ischemia-induced seizure susceptibility and efficacy of the GABAA-agonist phenobarbital (PB, with NKCC1 antagonist bumetanide (BTN as an adjunct treatment, we utilized permanent unilateral carotid-ligation to produce acute ischemic-seizures in postnatal day 7, 10 and 12 CD1 mice. Immediate post-ligation video-electroencephalograms (EEGs quantitatively evaluated baseline and post-treatment seizure burdens. Brains were examined for stroke-injury and western blot analyses to evaluate the expression of KCC2 and NKCC1. Severity of acute ischemic seizures post-ligation was highest at P7. PB was an efficacious anti-seizure agent at P10 and P12, but not at P7. BTN failed as an adjunct, at all ages tested and significantly blunted PB-efficacy at P10. Significant acute post-ischemic downregulation of KCC2 was detected at all ages. At P7, males displayed higher age-dependent seizure susceptibility, associated with a significant developmental lag in their KCC2 expression. This study established a novel neonatal mouse model of PB-resistant seizures that demonstrates age/sex-dependent susceptibility. The age-dependent profile of KCC2 expression and its post-insult downregulation may underlie the PB-resistance reported in this model. Blocking NKCC1 with low-dose BTN following PB treatment failed to improve PB-efficacy.

  19. Determination of benzalkonium chloride concentration in tobramycin in-situ forming eye gel by high performance liquid chromatography%高效液相色谱法测定妥布霉素眼用即用型凝胶中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    刘修树; 汤国平

    2012-01-01

    目的:建立高效液相色谱(HPLC)法测定妥布霉素眼用即用型凝胶中苯扎氯铵的含量.方法:HPLC法色谱柱为Kromasil C18(250.0 mm×4.6 mm,5 μm),0.07 mol/L乙酸铵溶液(含1%三乙胺,冰乙酸调节pH值至5.0)-乙腈(70:30)为流动相;检测波长215 nm,柱温35 ℃,流速0.8 ml/min.结果:苯扎氯铵在16.22~81.10 μg/ml范围内呈良好的线性关系(r=0.999 8,n=5),回归方程为Y ∧=6 091.9X+10 114,平均回收率为99.85%,RSD为1.07%.结论:该法简便、灵敏、准确、重复性好,可用于妥布霉素眼用即用型凝胶中的苯扎氯铵的含量控制.%Objective: To establish a high performance liquid chromatography ( HPLC ) method for the determination of benzalkonium chloride in tobramycin in-situ forming eye gel. Methods:HPLC,the chromatographic column was Kromasil C18(250. 0 mm ×4. 6 mm, 5 (j,m) ,the mobile phase 0.07 mol/L ammonium acetate solution(including 1% triethylamine,adjusting with glacial acetic acid to pH 5. 0) -acetonitrile(70: 30). The detection wavelength 215 nm,the column temperature 35 ℃ ,the flow rate was 0. 8 ml/min. Results: The calibration curve was linear in the range of 16. 22 —81. 10 μg/ml for benzalkonium chloride ( r = 0. 999 8, n = 5 ) , the regression equation was Y =6 091. 9X + 10 114,the average recovery was 99. 85% ,RSD was 1. 07%. Conclusions: The method is convenient, sensitive and accurate with a good repeatability for the determination of benzalkonium chloride in tobramycin in-situ forming eye gel.

  20. Effects of benzalkonium chloride on MUC1 in human conjunctival epithelial cells%苯扎氯铵对人结膜上皮细胞黏蛋白MUC1表达的影响

    Institute of Scientific and Technical Information of China (English)

    刘扬; 刘祖国; 许传超; 李朝阳; 陈小平; 虞东芳

    2010-01-01

    目的 探讨防腐剂苯扎氯铵(BAC)对体外培养的人结膜上皮细胞黏蛋白MUC1表达的影响及毒性作用.方法 采用培养的3~5代人结膜上皮细胞,将不同浓度(0.0100%、0.0050%、0.0010%、0.0005%、0.0001%)的BAC单次作用于结膜上皮细胞15 min,分别于处理细胞后0、6、12、24、48、72 h提取RNA及蛋白,采用RT-PCR及Western杂交方法检测MUC1表达水平.结果 0.0100%和0.0050%BAC作用后12~72 h可观察到结膜上皮细胞MUC1基因表达下调,0.0010%和0.0005%BAC作用后,24~48 h出现MUC1基因表达的下调,72 h恢复.0.0100%BAC作用后6~72 h检测到MUC1蛋白表达下降,而0.0050%BAC作用后12~72 h MUC1蛋白表达下降,0.0010%BAC作用后72 h MUC1蛋白表达减少.结论 BAC具有下调人结膜上皮细胞MUC1表达的作用,其下调作用具有时间依赖性和剂量依赖性.%Objective To investigate the effects of benzalkonium chloride ( BAC), a preservative used in many ophthalmic topical solutions, on mucinl ( MUC1 ) in human conjunctival epithelial cells in vitro.Methods Cultured epithelial cells obtained from human conjunctiva were exposed to medium containing BAC solutions at 0.0100% , 0.0050% , 0.0010% , 0.0005% and 0.0001% concentrations for a period of 15 min.Cells were examined after treatment and 6,12, 24, 48 and 72 h later.The relative expression of the MUC1 mucin gene was determined by conventional reverse transcription-polymerase chain reaction (RT-PCR).Monoclonal antibody for MUC1 was used in Western blot analysis to detect MUC1.Results Cell exposure to 0.0100% and 0.0050% BAC decreased the expression of MUC1 at gene level between 12 and 72 h after treatment Cells treated with 0.0010% and 0.0005% BAC decreased the expression of MUC1 between 24 and 48 h after treatment,recovered 72 h after treatment.At protein level, cells exposed to 0.0100% BAC decreased MUC1 between 24 and 72 h, 0.0050% BAC between 12 and 72 h, 0.0010% BAC 72 h later.Conclusions These results suggest

  1. 利用小鼠炎症模型评价苯扎氯铵的黏膜毒性%Determination of mucosal toxicity of benzalkonium chloride by using an inflammatory factor mice model

    Institute of Scientific and Technical Information of China (English)

    袁松华; 贲银银; 李亮助

    2012-01-01

    Objective To determine mucosal toxicity of benzalkonium chloride (BZK) by using an inflammatory factor mice model, so as to reveal the safety and application prospect of BZK. Methods BZK gel at the concentrations of 0. 02% ,0. 2% and 2% were intra-vaginally administered to the mice for 3 consecutive days, and vaginal washes of each mouse were collected daily. Six inflammatory cytokines in vaginal washes, including interleukin (IL-2, IL-4, IL-6 , IL-17A, tumor necrosis factor (TNF)- a and interferon (IFN)- y, were detected by a cytometric bead array (CBA) assay. Hematoxylin-eosin (HE) stain was also used in the present study to verify histopathological damages caused by different concentrations of BZK. Results Compared to the placebo group, BZK at 2% induced obvious disruptions on vaginal epithelium, while the groups treated with BZK at 0. 02% and 0. 2% had little histopathological change. However, BZK at 0. 2% significantly upregulated secretions of IL-6 and TNF-ain in vaginal washes, while BZK at both 0. 02% and 2% had no much impact on the expressions of these six cytokines. Conclusions BZK at 2% and 0. 2% caused toxicity on topical mucosal sites; BZK at 0. 02% displayed good tolerability for vaginal mucosa of the mice and BZK' s ability of inhibiting infections of pathogens needs further testing.%目的 利用小鼠黏膜炎症因子模型,研究不同浓度苯扎氯铵(BZK)对生殖道黏膜的刺激毒性,以探究BZK作为黏膜用药物的安全性和应用前景.方法 连续三天用浓度为0.02%、0.2%和2%的BZK凝胶处理小鼠阴道黏膜,每天收集小鼠阴道灌洗液,用多指标流式蛋白定量技术(Cytometric Bead Array,CBA)检测其中的6种炎症因子[白介素(Interleukin,IL)-2、IL-4、IL-6、IL-17A和肿瘤坏死因子(Tumor necrosis factor,TNF)-α、γ干扰素(Interferon γ,IFN)-γ]的表达情况;利用苏木紫-伊红(Hematoxylin-Eosin,HE)染色法对小鼠阴道黏膜的病理学损伤情况进行观察.结果 2%

  2. Corrosion susceptibility study of candidate pin materials for ALTC (Active Lithium/Thionyl Chloride) batteries

    Science.gov (United States)

    Bovard, Francine S.; Cieslak, Wendy R.

    1987-09-01

    The corrosion susceptibilities of eight alternate battery pin material candidates for ALTC (Active Lithium/Thionyl Chloride) batteries in 1.5M LiAlCl4/SOCl2 electrolyte have been investigated using ampule exposure and electrochemical tests. The thermal expansion coefficients of these candidate materials are expected to match Sandia-developed Li-corrosion resistant glasses. The corrosion resistances of the candidate materials, which included three stainless steels (15-5 PH, 17-4 PH, and 446), three Fe-Ni glass sealing alloys (Kovar, Alloy 52, and Niromet 426), a Ni-based alloy (Hastelloy B-2) and a zirconium-based alloy (Zircaloy), were compared to the reference materials Ni and 316L SS. All of the candidate materials showed some evidence of corrosion and, therefore, did not perform as well as the reference materials. The Hastelloy B-2 and Zircaloy are clearly unacceptable materials for this application. Of the remaining alternate materials, the 446 SS and Alloy 52 are the most promising candidates.

  3. 聚乙二醇滴眼液对拉坦前列腺素眼表毒性的中和作用%Neutralization of polyethylene glycol on ocular surface toxicity induced by benzalkonium chloride-preserved latanoprost

    Institute of Scientific and Technical Information of China (English)

    余芬芬; 钟毅敏; 李媚; 毛真; 郭歆星; 杨莎莎; 曹丹; 肖辉; 刘杏

    2013-01-01

    Background Reducing ocular surface toxicity induced by topical antiglaucoma medications,and thus improving the therapeutic compliance of glaucomatous patients to treating drug become an urgent issue in the long-term antiglaucomatous therapies.Whether polyethylene glycol,a new type of artificial tear,can play a protective role from ocular surface toxicity induced by topical antiglaucoma medications remains further study.Objective The present study was to investigate the protective effect of polyethylene glycol on ocular surface toxicity induced by prolonged use of benzalkonium chloride-preserved latanoprost eye drops.Methods Thirty adult female New Zealand rabbits were randomly divided into normal control group,phosphate buffer solution (PBS) group and polyethylene glycol eye drops group.PBS with 0.005% latanoprost was topically administered for consequent 60 days in the PBS group,and 0.005% latanoprost with polyethylene glycol eye drops was used at the same way in the polyethylene glycol group.Schirmer Ⅰ test,fluorescein and rose bengal staining of cornea and conjunctiva,conjunctiva impression cytology specimens collecting were performed before experiment as well as 31 and 61 days after administration of drug.Histomorphological and ultrastructural changes of cornea and conjunctiva were observed under the light microscopy,scanning and transmission electron microscopy on day 61.Results The score of corneal fluorescine staining was significantly different among the control group,PBS group and polyethylene glycol group (H =25.265,P<0.001 ;H=29.426,P<0.001) on day 31 and day 61.Significant difference also was found in the score of rose bengal staining of cornea and conjunctiva (H=26.167,P<0.001 ;H =29.212,P<0.001),Schirmer Ⅰ test value (F=4.746,P<0.05) and conjunctival goblet cell density (F=18.055,P<0.001).Compared with the control group,corneal fluorescein scores [0(0,1.0) vs.3 (2.0,3.0)] and rose bengal scores [0(0,1) vs.2(2,3)] were significantly

  4. Lactobacillus casei reduces susceptibility to type 2 diabetes via microbiota-mediated body chloride ion influx.

    Science.gov (United States)

    Zhang, Yong; Guo, Xiao; Guo, Jianlin; He, Qiuwen; Li, He; Song, Yuqin; Zhang, Heping

    2014-07-18

    Gut microbiota mediated low-grade inflammation is involved in the onset of type 2 diabetes (T2DM). In this study, we used a high fat sucrose (HFS) diet-induced pre-insulin resistance and a low dose-STZ HFS rat models to study the effect and mechanism of Lactobacillus casei Zhang in protecting against T2DM onset. Hyperglycemia was favorably suppressed by L. casei Zhang treatment. Moreover, the hyperglycemia was connected with type 1 immune response, high plasma bile acids and urine chloride ion loss. This chloride ion loss was significantly prevented by L. casei via upregulating of chloride ion-dependent genes (ClC1-7, GlyRα1, SLC26A3, SLC26A6, GABAAα1, Bestrophin-3 and CFTR). A shift in the caecal microflora, particularly the reduction of bile acid 7α-dehydroxylating bacteria, and fecal bile acid profiles also occurred. These change coincided with organ chloride influx. Thus, we postulate that the prevention of T2DM onset by L. casei Zhang may be via a microbiota-based bile acid-chloride exchange mechanism.

  5. 维生素A治疗苯扎氯铵诱导的小鼠干眼的实验研究%Therapeutic effects of Vitamin A on mouse dry eye induced by benzalkonium chloride topical medication

    Institute of Scientific and Technical Information of China (English)

    何欢; 刘祖国; 肖辛野; 林志荣; 周彤; 何卉

    2012-01-01

    Objective To investigate the therapeutic effect of Vitamin A on the recovery of dry eye that was induced by benzalkonium chloride (BAC) topical medication in the mouse.Methods In this randomized controlled experimental study,50 BALB/c mice were treated with the topical administration of 0.25% BAC to establish the dry eye condition.Based on the consistency of tear film break-up time (BUT),corneal fluorescein staining scores and inflammation index,the eyes were re-selected and 30 mice were randomly divided into three groups on day 21 after the BAC treatment,with 10 mice (20 eyes) in each group.Group C was set up as a blank control,while groups A and B were treated with 5000 IU/(g·ml) Vitamin A eye drops and microemulsion solvent drops,respectively.BUTs,corneal fluorescein staining scores,inflammation index and tear volumes were evaluated in each group on days 0,1,3,5 and 7 after the therapeutic treatment.Global specimens were collected on day 7.Sections were stained with hematoxylin and eosin (HE) or by periodic acid-Schiff (PAS) assay,and labeled with cytokeratin 10 (K10) antibody.The expression of K10 in the cornea and conjunctiva was quantified by Western Blot.The data were analyzed by one-way ANOVAs.Results On days 0,1,3 and 5,no clinical differences were observed among the groups.On day 7,the BUT values were (4.20±0.89)s,(3.32±1.01)s and (3.28±0.74)s in groups A,B and C,respectively.The BUT in group A was significantly longer than those in groups B and C (F=6.852,P=0.002).The corneal fluorescein staining scores were 3.74±1.31,5.47±1.81 and 5.83±1.54 in groups A,B and C,respectively.The scores in group A were significantly lower than those in groups B and C (F=8.853,P<0.01).No significant differences were found in the corneal inflammatory index or tear volume among the groups.Corneal morphology showed a loosened corneal epithelium feature in groups B and C,but comeal integrity in group A.PAS assay revealed similar goblet cell numbers between group A

  6. Benzalkonium Chloride Solution Combined with Calcium Alginate Dressings in Elderly Diabetic Foot Wounds:A Series of Clinical Studies%苯扎氯铵溶液联合藻酸钙敷料治疗老年糖尿病患者足部病变的效果

    Institute of Scientific and Technical Information of China (English)

    闫雅凤; 侯惠如; 杨晶; 刘志英; 曹春玲; 郝亚静; 邱振瑜; 李瑾竹

    2012-01-01

    Objective To evaluate the treatment results and nursing effects of benzalkonium chloride solution combined with calcium alginate dressings used in elderly diabetic foot wounds. Methods From January 2009 to September 2011,62 elderly diabetic patients with wounds in our hospital were randomly divided into observational group(n= 31) and control group(n = 31). The control group adopted the conventional iodophor disinfection and used a small dose of insulin and gentamicin to wash the wound with yarn ball isolation and gauze dressing method. Based on the conventional sterilization, the observational group used benzalkonium chloride solution for 5-10 min,and took calcium alginate dressing to cover the wound isolation. Comparisons were conducted on healing time, healing effect, the time and number of dressing of skin lesions and patient satisfaction with care. Results Significant differences were observed on healing time,healing effect, the number of dressing changes, patient care and overall satisfaction (satisfied, more satisfied,dissatisfied) between the two kinds of foot care methods(P<0. 01). Conclusion Benzalkonium chloridesolution in combination with calcium alginate dressings for elderly patients with diabetes care in the early foot lesions can effectively shorten the healing time and improve wound healing effect, to reduce the total dressing number of nursing staff and significantly improve patient satisfaction, which is a suitable early efficient method for elderly patients with diabetic foot wounds .%目的 探讨苯扎氯铵溶液联合藻酸钙敷料应用于老年糖尿病患者足部病变的治疗与护理效果.方法 便利抽样法选择2009年1月至2011年9月在解放军总医院住院的老年糖尿病足部病变患者62例,采用随机数字表法将其分为对照组和观察组各31例,对照组采用常规聚维酮碘消毒后使用硫酸庆大霉素加入小剂量普通胰岛素冲洗伤口、纱球隔离、纱布包扎的方法 ;观察组则

  7. Therapeutic effects of Pranoprofen on the mouse dry eye induced by topical medication of Benzalkonium Chloride%普拉洛芬治疗苯扎氯铵诱导小鼠干眼的研究

    Institute of Scientific and Technical Information of China (English)

    何欢; 刘祖国; 林志荣; 刘晓琛; 何卉; 肖启国

    2012-01-01

    ,联合用药组上皮规整;PAS染色示普拉洛芬组及氟米龙组的杯状细胞数量相当,均多于人工泪液组及空白对照组.普拉洛芬组及氟米龙组的角膜上皮层均几乎不表达K10,而人工泪液组及空白对照组仍阳性表达.普拉洛芬组及氟米龙处理组角膜中的TNF-α水平均有下降.结论 普拉洛芬具有抑制苯扎氯铵溶液局部点眼诱导干眼眼表炎症的作用,有望用于干眼眼表炎症的临床治疗.%Objective Randomized controlled experimental study to investigate the therapeutic effect and the possible mechanism of Pranoprofen on the recovery of dry eye induced by topical medication of Benzalkonium Chloride (BAC) in mouse.Methods It was an experimental study.Seventy BALB/c mice were treated with topical administration of 0.25% BAC to establish the dry eye condition.Based on the consistency of break-up time of tear-film ( BUT ),corneal fluorescein staining scores and inflammation index,the eyes were re-selected and randomly divided into four groups on day (D) 21 after the BAC treatment.Group A was set up as blank control,while group B,C and D were treated respectively with 0.1% sodium hyaluronate eye drops,0.1% fluorometholone eye drops plus 0.1% sodium hyaluronate eye drops,0.1% pranoprofen eye drops plus 0.1% sodium hyaluronate eye drops.BUTs,tear volumes,corneal fluorescein staining scores and inflammation index were evaluated in each group on DO,1,3 and 5 after the therapeutic treatment.Global specimens were collected on D6.Sections were stained with hematoxylin and eosin (HE) or by periodic acid-schiff (PAS) assay,and labeled with cytokeratin 10 (K10) antibody.The expression of tumor necrosis factor-α (TNF-α) in the cornea and conjunctiva was quantified by western blot.Results 72 eyes were included in the sequential experiment,18 eyes for each group.On DO,1 and 3,no clinical differences were observed among the groups.On D5,the BUT was (2.933 ± 0.320),(2.900 ±0

  8. 苯扎氯铵溶液膀胱冲洗预防留置导尿患者尿路感染的实效性评价%Effectiveness of bladder irrigation with benzalkonium chloride solution in prevention of urinary tract infections in indwelling catheterization patients

    Institute of Scientific and Technical Information of China (English)

    黄达飞; 周青英; 孙学斌; 郑定钦; 徐乃奋

    2015-01-01

    目的:评价苯扎氯铵溶液膀胱冲洗预防长期留置导尿患者尿路感染的实效性,探讨苯扎氯铵对尿路感染的预防效果。方法选择2013年5月-2014年5月在医院治疗需要长期留置导尿患者76例,按照膀胱冲洗方式的不同将其随机分为A、B组,每组各38例;A组患者采用0.0025%苯扎氯铵溶液进行膀胱冲洗,B组患者采用0.9%生理盐水溶液进行膀胱冲洗,观察并比较两组患者尿路感染情况。结果膀胱冲洗第1周和第2周后A组患者尿液细菌培养阳性率分别为15.79%和21.05%,明显低于B组的52.63%和71.05%,两组比较差异有统计学意义(P<0.05);A组患者尿液中白细胞计数分别为(6.7±3.0)个/HP和(8.7±4.0)个/HP ,均低于相应B组的(11.5±4.4)个/HP和(16.7±6.7)个/HP ,两组比较差异有统计学意义(P<0.05);A组中段尿中总细菌数少于B组,其各类菌株构成比差异有统计学意义(P<0.05)。结论苯扎氯铵溶液膀胱冲洗在预防长期留置导尿患者下尿路感染方面具有很好的效果,冲洗后细菌阳性率低,值得临床推广应用。%OBJECTIVE To evaluate the effectiveness of bladder irrigation with benzalkonium chloride solution in prevention of lower urinary tract infections in patients undergoing long‐term indwelling catheterization and observe the effect of benzalkonium chloride on prevention of the urinary tract infections .METHODS A total of 76 patients who needed to be treated with long‐term indwelling catheterization from May 2013 to May 2014 were enrolled in the study and randomly divided into the group A and group B according to the approach of bladder irrigation ,with 38 cases in each group .The group A was treated with bladder irrigation with 0 .0025% benzalkonium chloride so‐lution ,while the group B was given the bladder irrigation with 0 .9% normal saline solution .The

  9. HPLC determination of alkyl components in benzalkonium chloride and comparison between domestic and foreign products%高效液相色谱法测定苯扎氯铵中烷基组成的比例并比较国内外样品的差异

    Institute of Scientific and Technical Information of China (English)

    熊亚群; 刘雁鸣; 龙海燕; 彭琳; 艾俊涛

    2016-01-01

    Objective To determine the alkyl components in benzalkonium chloride by RP-HPLC method and compare domestic and foreign products.Methods Inertsil CN-3 chromatographic column (4.6 mm × 250 mm,5 μm) was used.The mobile phase was 0.1 mol · L-1 sodium acetate solution (using acetic acid to adjust pH to 5.0)-acetonitrile (53:47).The flow rate was 2.0 mL · min-1,the detection wavelength was 254 ran.The column temperature was 35 ℃.Results n-C12,n-C14 and n-C16 showed good linearity at 0.252-25.20 mg·mL-1,0.121-12.11 mg · mL-1and 0.018-1.844 mg · mL-1,respectively.The detection limits were 109.6,172.9 and 120.0ng,respectively.Recoveries of 3 homologs at different levels were at 97.8%-102.4% and the RSD was at 0.16%-1.2%.Conclusion This method can be used to the determine the alkyl compositions in benzalkonium chloride quickly and accurately.%目的 采用高效液相色谱法对苯扎氯铵中烷基组成的比例进行测定,并比较国内外样品的差异.方法 采用Inertsil CN-3色谱柱(4.6 mm×250 mm,5μm),以0.1 mol·L-醋酸钠溶液(醋酸调节pH至5.0)-乙腈(53∶47)为流动相,流速为2.0 mL·min-1,检测波长为254 nm,柱温为35℃.结果 n-C12、n-C14、n-C16分别在0.252~25.20、0.121~12.11、0.018~1.844 mg·mL-1与峰面积呈良好的线性关系,检出限分别为109.6、172.9、120.0 ng,3种单体的3个不同浓度的回收率在97.8%~102.4%,RSD 在0.16%~1.2%.结论 经方法学验证,本方法能快速、准确测定苯扎氯铵中烷基组成比例.

  10. Simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis%毛细管电泳法同时测定复方化学消毒剂中醋酸洗必泰和苯扎氯铵

    Institute of Scientific and Technical Information of China (English)

    宋宝花; 丁晓静; 李佳; 王志

    2012-01-01

    Benzalkonium chloride (BAC) is a mixture of alkyl substituted benzyl dimethylam-monium chloride homologs (C12-BAC, C14-BAC and C,6-BAC). Chlorhexidine acetate is a widely used effective component in compound chemical disinfectants. A method for the simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis (CE) was established. The CE analysis was carried out using an uncoated capillary with 50 |xm i. d. and 37 cm total length. The running buffer was 150 mmol/L NaH2PO4-62. 5 mmol/L H3PO4(pH 2.5) containing 40% (v/v) acetonitrile. The sample medium was 50 mmol/L acetic acid-acetonitrile (is I, v/v). The detection wavelength was 214 nm. The factors such as the buffer concentration and pH, the content of acetonitrile, which influenced the separation and accurate assay of compound chemical disinfectants were investigated in detail. The intra-day and inter-day precisions of the method were below 3. 0% and 3. 7%, respectively. The limits of detection (LOD, signal to noise ratio (S/N) =3) for chlorhexidine acetate, C12-BAC, C14-BAC and CI6-BAC were 0.3, 0.5, 0.5 and 0.5 mg/L, respectively. The limits of quantification (LOQ, S/N = 10) were 1.0, 1.5, 1.5, and 1. 5 mg/L, respectively. The corrected peak area and the mass concentration of the four components mentioned above showed good linear relationships within the ranges of 1. 0 - 400 mg/L ,1.5- 200 mg/L, 1. 5 -200 mg/L and 1. 5 -200 mg/L, with linear correlation coefficients (r) of 0. 999 5,0. 999 8 , 0. 999 7 and 0. 999 8, respectively. The established method was used for the determination of the four disinfectants in the compound chemical disinfectants. The results were in good agreement with those obtained by the high performance liquid chromatographic method.%建立了复方化学消毒剂中常用有效成分醋酸洗必泰和苯扎氯铵(C12-BAC、C14-BAC及C16-BAC)同时分离测定的毛细管电泳(CE)方法.以37 cm×50 μm未涂

  11. Biofilm Matrix Composition Affects the Susceptibility of Food Associated Staphylococci to Cleaning and Disinfection Agents

    OpenAIRE

    Annette eFagerlund; Solveig eLangsrud; Even eHeir; Maria Ingeborg Mikkelsen; Trond eMøretrø

    2016-01-01

    Staphylococci are frequently isolated from food processing environments, and it has been speculated whether survival after cleaning and disinfection with benzalkonium chloride-containing disinfectants is due to biofilm formation, matrix composition or benzalkonium chloride efflux mechanisms. Out of 35 food associated staphylococci, eight produced biofilm in a microtiter plate assay and were identified as Staphylococcus capitis (2), S. cohnii, S. epidermidis, S. lentus (2), and S. saprophyticu...

  12. Optimized Benzalkonium Chloride Gel: A Potential Vaginal Microbicides

    Institute of Scientific and Technical Information of China (English)

    Xun-cheng DING; Wei-hua LI; Jie-fei LI; Qiang-yi WANG

    2007-01-01

    Objective To develop an optimized BZK gel with good pharmaceutical effect and less toxicity to vaginal mucosa.Methods Four methods as below were used to research the spermicidal activity of BZK gel: 1)in vitro spermicidal test; 2) in vivo spermicidal test in rabbits; 3) anti-fertility test in rabbits; 4)contraceptive test in rabbits. Mucosal irritation test was used in rats to evaluate the safety of optimized BZK gel. Microbiological assessments were used to research anti-STI pathogens (including treponema pallidum, neisseria gonorrhoeae, trichomona vaginalis, candida albicans,ureaplama urealyticum, herpes simplex virus type-2, chlamydiae trachomatis) effect of optimized BZK gel.Results In vitro spermicidal test, EC50 of BZK gel was 0.029 mg/ml, a little higher than that of N-9 (0.019 mg/ml). The MIC of BZK gel was 0.25 mg/ml, similar to that of N-9 (0.20 mg/ml).The vaginal mucosal irritation test in rats showed that 0.429% BZK gel showed only minimal vaginal irritation, and did not damage the vaginal epithelium or cause local inflammation in rats. Microbiological assessments showed that optimized BZK gel could inhibit or inactivate common STI pathogens even after 3-fold or 5-fold dilution.Conclusion Optimized BZK gel was an effective microbicides.

  13. Biocide Susceptibility of Staphylococcus aureus CC398 and CC30 Isolates from Pigs and Identification of the Biocide Resistance Genes, qacG and qacC

    DEFF Research Database (Denmark)

    Seier-Petersen, Maria Amalie; Nielsen, Lene Nørby; Ingmer, Hanne

    2015-01-01

    farming (benzalkonium chloride, hydrogen peroxide, formaldehyde, sodium hypochlorite, and caustic soda). Furthermore, efflux pump activity, antimicrobial resistance profiles, hemolysis properties, and the presence of toxic shock syndrome toxin-1 (TSST-1) and Panton-Valentine Leukocidin (PVL...

  14. Effect of Organic Acid Additions on the General and Localized Corrosion Susceptibility of Alloy 22 in Chloride Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, R M; Giordano, C M; Rodr?guez, M A; Ilevbare, G O; Rebak, R B

    2007-08-28

    Electrochemical studies such as cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS) were performed to determine the corrosion behavior of Alloy 22 (N06022) in 1M NaCl solutions at various pH values from acidic to neutral at 90 C. All the tested material was wrought Mill Annealed (MA). Tests were also performed in NaCl solutions containing weak organic acids such as oxalic, acetic, citric and picric. Results show that the corrosion rate of Alloy 22 was significantly higher in solutions containing oxalic acid than in solutions of pure NaCl at the same pH. Citric and picric acids showed a slightly higher corrosion rate, and acetic acid maintained the corrosion rate of pure chloride solutions at the same pH. Organic acids revealed to be weak inhibitors for crevice corrosion. Higher concentration ratios, compared to nitrate ions, were needed to completely inhibit crevice corrosion in chloride solutions. Results are discussed considering acid dissociation constants, buffer capacity and complex formation constants of the different weak acids.

  15. Protection effect of sodium hyaluronate on ocular surface toxicity induced by Benzalkonium chloride-preserved brimonidine in rabbits%透明质酸钠对兔含苯扎氯铵溴莫尼定眼表毒性保护作用的研究

    Institute of Scientific and Technical Information of China (English)

    余芬芬; 刘杏; 钟毅敏; 毛真; 郭歆星; 李媚; 曹丹; 陈翔熙

    2013-01-01

    Objective To investigate the protective effects of sodium hyaluronate on ocular surface toxicity induced by a prolonged use of benzalkonium chloride-preserved Brimonidine eye drops.Methods Experimental study.Thirty adult female New Zealand rabbits were divided into three groups with randomized numbers design.Ten rabbits were treated with 0.2% Brimonidine eye drops and PBS (PBS group),the other ten rabbits with 0.2% Brimonidine combined with sodium hyaluronate eye drops (SH group),and control group received no treatment for 60 days.Schirmer test,fluorescein (FL) and Rose Bengal (RB) staining,conjunctival impression cytology specimens collecting were performed on day 0,31,and 61.Apoptosis of conjunctival epithelium was detected by in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay on day 61.Conjunctival inflammation was observed by hematoxylin eosin staining.Histomorphological changes of cornea and conjunctiva were observed by light microscopy,and scanning and transmission electron microscopy at day 61.Fluorescein and Rose Bengal scores were analysed by Kruskal-Wallis test.Schirmer scores,goblet cell density and inflammatory cells infiltration were analysed by repeated measures analysis of variance.Results There were significant differences in fluorescein and Rose bengal (H =22.031,15.303,P < 0.01) staining among the groups on day 61.Compared with the control group (FL:0,0-1,RB:0,0-1),fluorescein and Rose Bengal scores were significantly (P < 0.001) increased in PBS group (FL:1.5,1-2,RB:1,1-2),whereas was significantly (P < 0.001) decreased in SH group (FL:0,0-1 RB:1,0-1) when compared to PBS group.There were significant differences in aqueous tear production and goblet cell density (F =7.980,14.545,both P < 0.01) among the groups on day 61.Compared with the control group [(9.43 ± 0.57) mm,(87.73 ± 2.34/HP)],Schirmer scores and goblet cell density were significantly (P < 0.01) reduced in PBS-treated group [(6.61 ± 0

  16. Comparative analysis of the susceptibility to biocides and heavy metals of extended-spectrum β-lactamase-producing Escherichia coli isolates of human and avian origin, Germany.

    Science.gov (United States)

    Deus, Daniela; Krischek, Carsten; Pfeifer, Yvonne; Sharifi, Ahmad Reza; Fiegen, Ulrike; Reich, Felix; Klein, Guenter; Kehrenberg, Corinna

    2017-02-08

    A total of 174 extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates collected from humans (n=140) and healthy broiler chickens (n = 34) was included in the study. The MIC values of alkyl diaminoethyl glycin hydrochloride, benzethonium chloride, benzalkonium chloride, chlorhexidine, acriflavine, copper sulfate, silver nitrate and zinc chloride were determined by the broth microdilution method. Significant differences in MIC distributions were found between human and avian isolates and between CTX-M-, SHV- and TEM-type ESBL E. coli for chlorhexidine, silver nitrate, zinc chloride and copper sulfate by statistical analysis. Isolates with reduced susceptibility were investigated for the presence and localization of tolerance-mediating genes by PCR analysis and Southern blotting. The genes emrE, mdfA, sugE(c), cueO, copA, zntA and zitB were commonly present in isolates with elevated MICs, while the genes qacE∆1, qacF, qacH, sugE(p), cusC and pcoA, were less prevalent. In several isolates, a plasmid localization of the genes qacE∆1, qacF, qacH and sugE(p) on large plasmids >20 kb was detected.

  17. Genetic relatedness, antimicrobial and biocide susceptibility comparative analysis of methicillin-resistant and -susceptible Staphylococcus pseudintermedius from Portugal.

    Science.gov (United States)

    Couto, Natacha; Belas, Adriana; Couto, Isabel; Perreten, Vincent; Pomba, Constança

    2014-08-01

    Forty methicillin-resistant and -susceptible Staphylococcus pseudintermedius (MRSP and MSSP, respectively) from colonization and infection in dogs and cats were characterized for clonality, antimicrobial, and biocide susceptibility. MSSP were genetically more diverse than MRSP by multi-locus sequence typing and pulsed-field gel electrophoresis. Three different spa types (t06, t02, t05) and two SCCmec types (II-III and V) were detected in the MRSP isolates. All MRSP and two MSSP strains were multidrug-resistant. Several antibiotic resistance genes (mecA, blaZ, tet(M), tet(K), aac(6')-Ie-aph(2')-Ia, aph(3')-III, ant(6)-Ia, sat4, erm(B), lnu(A), dfr(G), and catp(C221)) were identified by microarray and double mutations in the gyrA and grlA genes and a single mutation in the rpoB gene were detected by sequence analysis. No differences were detected between MSSP and MRSP in the chlorhexidine acetate (CHA) minimum inhibitory concentrations (MICs). However, two MSSP had elevated MIC to triclosan (TCL) and one to benzalkonium chloride and ethidium bromide. One MSSP isolate harboured a qacA gene, while in another a qacB gene was detected. None of the isolates harboured the sh-fabI gene. Three of the biocide products studied had high bactericidal activity (Otodine(®), Clorexyderm Spot Gel(®), Dermocanis Piocure-M(®)), while Skingel(®) failed to achieve a five log reduction in the bacterial counting. S. pseudintermedius have become a serious therapeutic challenge in particular if methicillin- resistance and/or multidrug-resistance are involved. Biocides, like CHA and TCL, seem to be clinically effective and safe topical therapeutic options.

  18. Adaptive Resistance and Differential Protein Expression of Salmonella enterica Serovar Enteritidis Biofilms Exposed to Benzalkonium Chloride▿

    Science.gov (United States)

    Mangalappalli-Illathu, Anil K.; Korber, Darren R.

    2006-01-01

    The development of adaptive resistance of Salmonella enterica serovar Enteritidis ATCC 4931 biofilms following exposure to benzalkonium chloride (BC) either continuously (1 μg ml−1) or intermittently (10 μg ml−1 for 10 min daily) was examined. Biofilms adapted to BC over a 144-h period could survive a normally lethal BC challenge (500 μg ml−1 for 10 min) and then regrow, as determined by increases in biofilm thickness, total biomass, and the ratio of the viable biomass to the nonviable biomass. Exposure of untreated control biofilms to the lethal BC challenge resulted in biofilm erosion and cell death. Proteins found to be up-regulated following BC adaptation were those involved in energy metabolism (TpiA and Eno), amino acid and protein biosynthesis (WrbA, TrxA, RplL, Tsf, Tuf, DsbA, and RpoZ), nutrient binding (FruB), adaptation (CspA), detoxification (Tpx, SodB, and a probable peroxidase), and degradation of 1,2-propanediol (PduJ and PduA). A putative universal stress protein (YnaF) was also found to be up-regulated. Proteins involved in proteolysis (DegQ), cell envelope formation (RfbH), adaptation (UspA), heat shock response (DnaK), and broad regulatory functions (Hns) were found to be down-regulated following adaptation. An overall increase in cellular protein biosynthesis was deduced from the significant up-regulation of ribosomal subunit proteins, translation elongation factors, and amino acid biosynthesis protein and down-regulation of serine endoprotease. The cold shock response, stress response, and detoxification are suggested to play roles in the adaptive resistance of Salmonella serovar Enteritidis biofilms to BC. PMID:16940079

  19. Isolation and characterization of resistant variants from Salmonella Typhimurium cell cultures treated with benzalkonium chloride

    NARCIS (Netherlands)

    Castelijn, G.A.A.; Veen, van der S.; Moezelaar, H.R.; Abee, T.; Zwietering, M.H.

    2014-01-01

    An efficient disinfection strategy within the food industry is needed to ensure food safety and prevent the spreading of foodborne pathogens such as Salmonella Typhimurium. However, several factors affect the efficiency of disinfection treatments resulting in low level exposure of the bacterial flor

  20. Disinfectant and Antimicrobial Susceptibility Profiles of the Big Six Non-O157 Shiga Toxin-Producing Escherichia coli Strains from Food Animals and Humans.

    Science.gov (United States)

    Beier, Ross C; Franz, Eelco; Bono, James L; Mandrell, Robert E; Fratamico, Pina M; Callaway, Todd R; Andrews, Kathleen; Poole, Toni L; Crippen, Tawni L; Sheffield, Cynthia L; Anderson, Robin C; Nisbet, David J

    2016-08-01

    The disinfectant and antimicrobial susceptibility profiles of 138 non-O157 Shiga toxin-producing Escherichia coli strains (STECs) from food animals and humans were determined. Antimicrobial resistance (AMR) was moderate (39.1% of strains) in response to 15 antimicrobial agents. Animal strains had a lower AMR prevalence (35.6%) than did human strains (43.9%) but a higher prevalence of the resistance profile GEN-KAN-TET. A decreasing prevalence of AMR was found among animal strains from serogroups O45 > O145 > O121 > O111 > O26 > O103 and among human strains from serogroups O145 > O103 > O26 > O111 > O121 > O45. One animal strain from serogroups O121 and O145 and one human strain from serogroup O26 had extensive drug resistance. A high prevalence of AMR in animal O45 and O121 strains and no resistance or a low prevalence of resistance in human strains from these serogroups suggests a source other than food animals for human exposure to these strains. Among the 24 disinfectants evaluated, all strains were susceptible to triclosan. Animal strains had a higher prevalence of resistance to chlorhexidine than did human strains. Both animal and human strains had a similar low prevalence of low-level benzalkonium chloride resistance, and animal and human strains had similar susceptibility profiles for most other disinfectants. Benzyldimethylammonium chlorides and C10AC were the primary active components in disinfectants DC&R and P-128, respectively, against non-O157 STECs. A disinfectant FS512 MIC ≥ 8 μg/ml was more prevalent among animal O121 strains (61.5%) than among human O121 strains (25%), which may also suggest a source of human exposure to STEC O121 other than food animals. Bacterial inhibition was not dependent solely on pH but was correlated with the presence of dissociated organic acid species and some undissociated acids.

  1. 苯扎溴铵溶液防治皮肤创伤愈合瘢痕的临床观察%Clinical observation on benzalkonium bromide solution preventing skin wound healing and scar treatment

    Institute of Scientific and Technical Information of China (English)

    顾家富; 晋继忠

    2011-01-01

    AIM: To observe 0.1 % benzalkonium bromide solution on the prevention and treatment of skin wound healing and scar treatment. METHODS: 974 cases of trauma were randomly divided into treatment group and control group each for 487 cases. 0.5% of the complex with iodine solution was used for skin disinfection. 3% hydrogen peroxide solution, 0.9% sodium chloride injection, 0.1% benzalkonium bromide solution were continuously used to clean the wound. The 0.1 % benzalkonium bromide solution was wet compressed after suture with bandage wounds, once every 2 days to wound healing in treatment group. 3 % hydrogen peroxide solution and 0.9% sodium chloride injection were used to clear the wound in the control group, then bandage usually. The long-term healing scar of two groups were observed. RESULTS: The Vancouver scar scale of two groups had significantly difference in 12 months after skin wound healing, the treatment group was lower. CONCLUSION: 0.1 % benzalkonium bromide solution has preventive effect on the skin and scar formation after wound healing.%目的:观察0.1%苯扎溴铵溶液对皮肤创伤愈合瘢痕的防治疗效.方法:将974例创伤患者随机分为治疗组及对照组各487例,用0.5%的络合碘溶液消毒皮肤,治疗组用3%过氧化氢溶液、0.9%氯化钠注射液、0.1%苯扎溴铵溶液依次清创伤口,缝合后用0.1%苯扎溴铵溶液湿敷包扎伤口,每2 d一次,至伤口愈合,对照组用3%过氧化氢溶液和0.9%氯化钠注射液清创伤口,缝合后常规包扎,观察两组远期皮肤愈合瘢痕的形成.结果:皮肤创伤愈合12月后两组的温哥华瘢痕量表评分差异显著,治疗组低于对照组的评分.结论:0.1%苯扎溴铵溶液对皮肤创伤愈合后的瘢痕形成有防治疗效.

  2. Chloride transference during electrochemical chloride extraction process

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Chemical titration method and lab-made chloride probes were jointly adopted to investigate the effects of water-to-cement (W/C) ratio and the impressed current density on chloride transport for cement-based materials during electrochemical chloride extraction (ECE) process.The dissolution of bound chlorides and the effect of current density on dissolution were analyzed.The variations of chloride concentration at different depths and the chloride transference process were monitored.Test results show that W/C ratios adopted have slight influence on chloride extraction,while chloride extraction efficiency is mainly determined by the impressed current density.During ECE process a portion of bound chloride ions dissolved and the amount of bound chlorides released is directly proportional to current density.

  3. Analysis of benzalkonium bromide and benzalkonium chloride by liquid chromatography%苯扎溴铵、苯扎氯铵的液相色谱分析

    Institute of Scientific and Technical Information of China (English)

    赵文英; 张青; 武智强; 范志先

    2015-01-01

    建立了苯扎溴铵、苯扎氯铵的高效液相色谱定量和离子色谱定性鉴别的分析方法.定量采用HPLC-DAD,Elite SinoChrom ODS-BP色谱柱,流动相为甲醇:2.4 mmol/L三氟乙酸水溶液=77∶23(V/V);定性采用IEC-CD鉴别C1-或Br-.以十二烷基二甲基苄基溴化铵为标样,在10~800 mg/L浓度范围内,线性关系良好(r=0.9998);2个质量浓度添加水平的平均回收率为100.17%和99.94%.8次平行测定的样品RSD为0.50%.对市场上的3个苯扎溴铵样品进行了检测,有2个不合有溴离子.

  4. Tribenzylammonium chloride

    Directory of Open Access Journals (Sweden)

    Waly Diallo

    2014-05-01

    Full Text Available Single crystals of the title salt, C21H21NH+·Cl−, were isolated as a side product from the reaction involving [(C6H5CH23NH]2[HPO4] and Sn(CH33Cl 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.

  5. Biofilm Matrix Composition Affects the Susceptibility of Food Associated Staphylococci to Cleaning and Disinfection Agents

    Science.gov (United States)

    Fagerlund, Annette; Langsrud, Solveig; Heir, Even; Mikkelsen, Maria I.; Møretrø, Trond

    2016-01-01

    Staphylococci are frequently isolated from food processing environments, and it has been speculated whether survival after cleaning and disinfection with benzalkonium chloride (BC)-containing disinfectants is due to biofilm formation, matrix composition, or BC efflux mechanisms. Out of 35 food associated staphylococci, eight produced biofilm in a microtiter plate assay and were identified as Staphylococcus capitis (2), S. cohnii, S. epidermidis, S. lentus (2), and S. saprophyticus (2). The eight biofilm producing strains were characterized using whole genome sequencing. Three of these strains contained the ica operon responsible for production of a polysaccharide matrix, and formed a biofilm which was detached upon exposure to the polysaccharide degrading enzyme Dispersin B, but not Proteinase K or trypsin. These strains were more tolerant to the lethal effect of BC both in suspension and biofilm than the remaining five biofilm producing strains. The five BC susceptible strains were characterized by lack of the ica operon, and their biofilms were detached by Proteinase K or trypsin, but not Dispersin B, indicating that proteins were major structural components of their biofilm matrix. Several novel cell wall anchored repeat domain proteins with domain structures similar to that of MSCRAMM adhesins were identified in the genomes of these strains, potentially representing novel mechanisms of ica-independent biofilm accumulation. Biofilms from all strains showed similar levels of detachment after exposure to alkaline chlorine, which is used for cleaning in the food industry. Strains with qac genes encoding BC efflux pumps could grow at higher concentrations of BC than strains without these genes, but no differences were observed at biocidal concentrations. In conclusion, the biofilm matrix of food associated staphylococci varies with respect to protein or polysaccharide nature, and this may affect the sensitivity toward a commonly used disinfectant. PMID:27375578

  6. Differential Adaptive Response and Survival of Salmonella enterica Serovar Enteritidis Planktonic and Biofilm Cells Exposed to Benzalkonium Chloride▿

    Science.gov (United States)

    Mangalappalli-Illathu, Anil K.; Vidović, Sinisa; Korber, Darren R.

    2008-01-01

    This study examined the adaptive response and survival of planktonic and biofilm phenotypes of Salmonella enterica serovar Enteritidis adapted to benzalkonium chloride (BC). Planktonic cells and biofilms were continuously exposed to 1 μg ml−1 of BC for 144 h. The proportion of BC-adapted biofilm cells able to survive a lethal BC treatment (30 μg ml−1) was significantly higher (4.6-fold) than that of BC-adapted planktonic cells. Similarly, there were 18.3-fold more survivors among the BC-adapted biofilm cells than among their nonadapted (i.e., without prior BC exposure) cell counterparts at the lethal BC concentration, and this value was significantly higher than the value for BC-adapted planktonic cells versus nonadapted cells (3.2-fold). A significantly higher (P < 0.05) proportion of surviving cells was noticed among BC-adapted biofilm cells relative to BC-adapted planktonic cells following a 10-min heat shock at 55°C. Fatty acid composition was significantly influenced by phenotype (planktonic cells or biofilm) and BC adaptation. Cell surface roughness of biofilm cells was also significantly greater (P < 0.05) than that of planktonic cells. Key proteins upregulated in BC-adapted planktonic and biofilm cells included CspA, TrxA, Tsf, YjgF, and a probable peroxidase, STY0440. Nine and 17 unique proteins were upregulated in BC-adapted planktonic and biofilm cells, respectively. These results suggest that enhanced biofilm-specific upregulation of 17 unique proteins, along with the increased expression of CspA, TrxA, Tsf, YjgF, and a probable peroxidase, phenotype-specific alterations in cell surface roughness, and a shift in fatty acid composition conferred enhanced survival to the BC-adapted biofilm cell population relative to their BC-adapted planktonic cell counterparts. PMID:18663028

  7. The leaves of Diospyros kaki exert beneficial effects on a benzalkonium chloride–induced murine dry eye model

    Science.gov (United States)

    Kim, Kyung-A; Hyun, Lee Chung; Jung, Sang Hoon

    2016-01-01

    Purpose In this study, the beneficial effects of the oral administration of ethanol extract of Diospyros kaki (EEDK) were tested on a mouse dry eye model induced by benzalkonium chloride (BAC). Methods A solution of 0.2% BAC was administered topically to mouse eyes for 14 days, twice daily, to induce dry eye. Various concentrations of EEDK were administrated daily by oral gavage for 14 days after BAC treatment. Preservative-free eye drops were instilled in the positive-control group. The tear secretion volume (Schirmer’s test), tear break-up time (BUT), and fluorescein score were measured on the ocular surface. BAC-induced corneal damage was tested with hematoxylin-eosin staining. Moreover, apoptotic cell death in the corneal epithelial layer was investigated with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. The protein expression level of interleukin-1alpha (IL-1α), IL-1β, IL-6, tumor necrosis factor- alpha (TNF-α), and monocyte chemotactic protein-1 (MCP-1) was determined with western blot analysis. Furthermore, squamous metaplasia in the corneal epithelial layer was detected with immunofluorescent staining for cytokeratine-10. The cellular proliferation in the cornea was examined with immunohistochemical staining for Ki-67. Results EEDK treatment resulted in prolonged BUT, decreased fluorescein score, increased tear volume, and smoother epithelial cells compared with BAC treatment alone in the cornea. Moreover, EEDK treatment inhibited the inflammatory response and corneal epithelial cell death in a BAC-induced murine dry eye model, and changes in squamous cells were inhibited. Proliferative activity in the corneal epithelium cells was improved with EEDK. Conclusions EEDK could be a potential therapeutic agent in the clinical treatment of dry eye. PMID:27110091

  8. Stress Corrosion Cracking of an Austenitic Stainless Steel in Nitrite-Containing Chloride Solutions

    Directory of Open Access Journals (Sweden)

    R. K. Singh Raman

    2014-12-01

    Full Text Available This article describes the susceptibility of 316L stainless steel to stress corrosion cracking (SCC in a nitrite-containing chloride solution. Slow strain rate testing (SSRT in 30 wt. % MgCl2 solution established SCC susceptibility, as evidenced by post-SSRT fractography. Addition of nitrite to the chloride solution, which is reported to have inhibitive influence on corrosion of stainless steels, was found to increase SCC susceptibility. The susceptibility was also found to increase with nitrite concentration. This behaviour is explained on the basis of the passivation and pitting characteristics of 316L steel in chloride solution.

  9. 苯扎溴铵酊处方改进及苯扎溴铵的含量测定%Improvement of prescription on Benzalkonium Bromide Tincture and de-termination of benzalkonium bromide

    Institute of Scientific and Technical Information of China (English)

    吴海伟; 王晓青; 刘皈阳; 马建丽

    2015-01-01

    Objective To improve prescription of Benzalkonium Bromide Tincture and establish a titration method in determination for content of benzalkonium bromide in Benzalkonium Bromide Alcoholic Solution (eosin was removed from Benzalkonium Bromide Tincture). Methods The content of benzalkonium bromide was detected by setting up capacity analysis method, and found eosin can affect the result of content determination at different degree, therefore eosin com-position was removed from the prescription. The content of benzalkonium bromide in Benzalkonium Bromide Alcoholic Solution was detected by titration method with tetraphenylboron sodium volumetric solution (0.02 mol/L). Results Ben-zalkonium Bromide Tincture changed to Benzalkonium Bromide Alcohol Solution, in content determination, the change of titration end point was obvious and easy to judge. Within the range from 0.4 mg/mL to 1.4 mg/mL, benzalkonium bromide presented a good linear relationship with the consumption volume of tetraphenylboron sodium volumetric solu-tion (r=0.9995), and the equation of linear regression was V=18.3C-0.32. The average recovery of benzalkonium bro-mide in low, middle and high dose was 99.12%, and RSD was 0.84%. Conclusion The method is simple, fast and ac-curate, it can be used for the quality control of Benzalkonium Bromide Alcoholic Solution.%目的:改进苯扎溴铵酊处方,并建立容量分析法测定苯扎溴铵醇溶液(苯扎溴铵酊去除曙红成分)中苯扎溴铵的含量。方法在建立容量分析法测定苯扎溴铵的含量时,发现曙红在不同程度上均能影响含量测定结果,故将曙红成分从处方中删去。采用四苯硼钠(0.02 mol/L)为滴定液,滴定苯扎溴铵醇溶液中苯扎溴铵的含量。结果苯扎溴铵酊制剂更改为苯扎溴铵醇溶液,在含量测定中,滴定终点变化明显,易于判断。苯扎溴铵在浓度0.4~1.4 mg/mL的范围内与消耗四苯硼钠滴定液体积呈良好线性关系,r=0

  10. Therapeutic Effects of Sodium Hyaluronate on Ocular Surface Damage Induced by Benzalkonium Chloride Preserved Anti-glaucoma Medications

    Directory of Open Access Journals (Sweden)

    Xing Liu

    2015-01-01

    Conclusions: SH significantly improved both symptoms and signs of ocular surface damage in patients with BAC-preserved anti-glaucoma medications treatment. SH could be proposed as a new attempt to reduce ocular surface toxicity, and alleviate symptoms of ocular surface damage in BAC-preserved anti-glaucoma medications treatment.

  11. Alkylrhodamines enhance the toxicity of clotrimazole and benzalkonium chloride by interfering with yeast pleiotropic ABC-transporters.

    Science.gov (United States)

    Knorre, Dmitry A; Besedina, Elizaveta; Karavaeva, Iuliia E; Smirnova, Ekaterina A; Markova, Olga V; Severin, Fedor F

    2016-06-01

    ABC-transporters with broad substrate specificity are responsible for pathogenic yeast resistance to antifungal compounds. Here we asked whether highly hydrophobic chemicals with delocalized positive charge can be used to overcome the resistance. Such molecules efficiently penetrate the plasma membrane and accumulate inside the cells. We reasoned that these properties can convert an active efflux of the compounds into a futile cycle thus interfering with the extrusion of the antibiotics. To test this, we studied the effects of several alkylated rhodamines on the drug resistance of yeast Saccharomyces cerevisiae We found that octylrhodamine synergetically increases toxicity of Pdr5p substrate-clotrimazole, while the others were less effective. Next, we compared the contributions of three major pleiotropic ABC-transporters (Pdr5p, Yor1p, Snq2p) on the accumulation of the alkylated rhodamines. While all of the tested compounds were extruded by Pdr5p, Yor1p and Snq2p showed narrower substrate specificity. Interestingly, among the tested alkylated rhodamines, inactivation of Pdr5p had the strongest effect on the accumulation of octylrhodamine inside the cells, which is consistent with the fact that clotrimazole is a substrate of Pdr5p. As alkylated rhodamines were shown to be non-toxic on mice, our study makes them potential components of pharmacological antifungal compositions.

  12. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents the state-of-the art: an analytical model which describes chloride profiles in concrete as function of depth...... makes physical sense for the design engineer, i.e. the achieved chloride diffusion coefficients at 1 year and 100 years, D1 and D100 respectively, and the corresponding achieved chloride concentrations at the exposed concrete surface, C1 and C100. Data from field exposure supports the assumption of time...... dependent surface chloride concentrations and the diffusion coefficients. Model parameters for Portland cement concretes with and without silica fume and fly ash in marine atmospheric and submerged South Scandinavian environment are suggested in a companion paper based on 10 years field exposure data....

  13. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents experimentally based design parameters for Portland cement concretes with and without silica fume and fly ash...... in marine atmospheric and submersed South Scandinavian environment. The design parameters are based on sequential measurements of 86 chloride profiles taken over ten years from 13 different types of concrete. The design parameters provide the input for an analytical model for chloride profiles as function...

  14. 苯扎溴铵生产的风险分析及安全措施%Hazard Analysis and Safety Measures for the Production of Benzalkonium Bromide

    Institute of Scientific and Technical Information of China (English)

    何伟平

    2015-01-01

    介绍了苯扎溴铵的反应原理及生产工艺。分析了其生产过程中的物质、工艺、设备等危险有害因素;结果表明其生产过程中涉及二甲胺、氯化苄、二甲基苄胺等危险化学品;若生产工艺和设备缺陷导致泄漏等,则存在火灾、爆炸、中毒等危险有害因素。并提出了安全管理、主要工艺技术和装置、设备检维修、事故应急救援等安全对策措施,建议安全设计和生产活动中应充分考虑这些危险有害因素,加强安全预防。%The production process and chemical reaction principle of benzalkonium bromide were introduced briefly. The material hazardous factors, process hazardous factors and equipment hazardous factors in the production were analyzed. The results showed that the production process involved hazardous chemicals such as dimethylamine, benzyl chloride and dimethyl benzylamine. If there were serious defects in the production process and equipments, the chemical leak could cause fire, explosion and poisoning in the production. Safety measures were put forward for the security management, major production process and installation, equipment maintenance and emergency rescue to prevent hazardous factors. The security precautions were strengthened, which was necessary to take these hazardous factors into fully consideration in the safety design and the production activities.

  15. Lithium Sulfuryl Chloride Battery.

    Science.gov (United States)

    Primary batteries , Electrochemistry, Ionic current, Electrolytes, Cathodes(Electrolytic cell), Anodes(Electrolytic cell), Thionyl chloride ...Phosphorus compounds, Electrical conductivity, Calibration, Solutions(Mixtures), Electrical resistance, Performance tests, Solvents, Lithium compounds

  16. Electoral Susceptibility

    CERN Document Server

    Levine, G C; Cerise, J E

    2012-01-01

    In the United States electoral system, a candidate is elected indirectly by winning a majority of electoral votes cast by individual states, the election usually being decided by the votes cast by a small number of "swing states" where the two candidates historically have roughly equal probabilities of winning. The effective value of a swing state in deciding the election is determined not only by the number of its electoral votes but by the frequency of its appearance in the set of winning partitions of the electoral college. Since the electoral vote values of swing states are not identical, the presence or absence of a state in a winning partition is generally correlated with the frequency of appearance of other states and, hence, their effective values. We quantify the effective value of states by an {\\sl electoral susceptibility}, $\\chi_j$, the variation of the winning probability with the "cost" of changing the probability of winning state $j$. We study $\\chi_j$ for realistic data accumulated for the 201...

  17. HPLC法测定吡嘧司特钾滴眼液中苯扎溴铵和苯扎氯铵量%Determination of Benzalkonium Bromide and Benzalkonium Chloride in Pemirolast Potassium Eye Drops by HPLC

    Institute of Scientific and Technical Information of China (English)

    刘春亮

    2013-01-01

    目的 建立HPLC法测定吡嘧司特钾滴眼液中苯扎溴铵和苯扎氯铵的含量.方法 色谱柱:C18(4.6 mm×150mm,5μm);流动相:0.02 mol·L-1庚烷磺酸钠溶液(含0.1%三乙胺,用磷酸调节pH为3.45±0.1)-乙腈(35∶65);检测波长:210 nm;柱温:40℃.结果 苯扎溴铵在49.86~997.2 ng范围内线性关系良好(r=0.9999),最小检出量为0.15 ng,平均回收率为97.4%,RSD为1.0%;苯扎氯铵在9.912~24.78 ng范围内呈良好的线性关系(r=0.9999),最小检出量为0.85 ng,平均回收率为99.9%,RSD为1.0%.结论 本方法简便、快速、准确、灵敏度高、重复性好,可用于吡嘧司特钾滴眼液中苯扎溴铵和苯扎氯铵的含量测定.

  18. Oxomemazine hydro-chloride.

    Science.gov (United States)

    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⋯π inter-actions.

  19. Chloride on the Move

    KAUST Repository

    Li, Bo

    2017-01-09

    Chloride (Cl−) is an essential plant nutrient but under saline conditions it can accumulate to toxic levels in leaves; limiting this accumulation improves the salt tolerance of some crops. The rate-limiting step for this process – the transfer of Cl− from root symplast to xylem apoplast, which can antagonize delivery of the macronutrient nitrate (NO3−) to shoots – is regulated by abscisic acid (ABA) and is multigenic. Until recently the molecular mechanisms underpinning this salt-tolerance trait were poorly defined. We discuss here how recent advances highlight the role of newly identified transport proteins, some that directly transfer Cl− into the xylem, and others that act on endomembranes in ‘gatekeeper’ cell types in the root stele to control root-to-shoot delivery of Cl−.

  20. 一种苯扎氯铵复方消毒剂的性能观察%OBSERVATION ON PROPERTIES OF A COMPOUND BENZALKONIUM CHLORIDE DISINFECTANT

    Institute of Scientific and Technical Information of China (English)

    孙克勤; 姜霞; 郭金铭; 李月平; 宋立江; 韩艳淑; 崔玉杰

    2010-01-01

    目的:观察一种苯扎氯铵复方消毒剂的杀菌效果及其相关性能.方法:采用悬液定量杀菌试验和动物试验方法进行了实验室观察.结果:该复方消毒液含苯扎氯铵1 840 mg/L,性能稳定.用含苯扎氯铵1 460 mg/L的该消毒剂溶液,作用1.5 min,对悬液内金黄色葡萄球菌、铜绿假单胞菌和白色念珠菌的杀灭对数值均>5.00.该消毒液对小鼠急性经口毒性LD50均大于5 000 mg/kg(体重),小鼠骨髓嗜多染红细胞微核试验结果均为阴性.一次完整皮肤刺激试验、急性眼刺激试验、阴道黏膜刺激试验均无刺激作用.结论:该消毒剂有良好的杀菌作用,毒性低.

  1. 苯扎氯铵抑制微生物污垢的实验研究%Experimental Research on Biofouling Inhibition of Benzalkonium Chloride

    Institute of Scientific and Technical Information of China (English)

    常思远; 杨倩鹏; 史琳

    2015-01-01

    再生水源热泵系统换热表面上的微生物污垢是影响系统效率和安全的重要问题.苯扎氯铵能抑制微生物污垢的生长.本文进行挂片实验模拟微生物污垢形成的过程.成垢过程中每天将挂片在苯扎氯铵溶液中浸泡10 min,考察了溶液浓度和温度对抑垢效果的影响.对比了苯扎氯铵和次氯酸钠的抑垢效果,并考察了细菌对苯扎氯铵的抗药性.实验结果表明,苯扎氯铵对微生物污垢有抑制作用,该作用随浓度和温度的上升而增强,但会随时间逐渐减弱.

  2. 氧氟沙星滴眼液中苯扎氯铵的HPLC测定%Determination of Benzalkonium Chloride in Ofloxacin Eye Drops by HPLC

    Institute of Scientific and Technical Information of China (English)

    陈秋芬; 王小琳

    2005-01-01

    建立了离子对高效液相色谱法,测定氧氟沙星滴眼液中苯扎氯铵的含量.采用C18色谱柱,以0.02mol/L庚烷磺酸钠溶液(含0.1%三乙胺,pH 3.45±0.1)-乙腈(35:65)为流动相,检测波长210nm,柱温40℃.苯扎氯铵在10~70μg/ml浓度范围内线性关系良好(r=0.9997),方法平均回收率100.1%.

  3. 一种苯扎氯铵消毒液杀菌效果观察%OBSERVATION ON GERMICIDAL EFFICACY OF A BENZALKONIUM CHLORIDE DISINFECTANT SOLUTION

    Institute of Scientific and Technical Information of China (English)

    李春梅; 钟晓祝

    2010-01-01

    目的 观察一种含苯扎氯铵的皮肤黏膜消毒液的杀菌效果.方法 采用悬液定量杀菌试验方法,在实验室对其杀灭细菌繁殖体和真菌的效果进行了观察.结果 以1 000 mg/L苯扎氯铵消毒液作用1 min,对悬液中的大肠埃希菌、金黄色葡萄球菌和白色念珠菌的平均杀灭对数值均达5.0以上.结论 该苯扎氯铵消毒液对细菌繁殖体和真菌具有良好的杀灭效果.

  4. Efficacy and safety of benzalkonium chloride-free fixed-dose combination of latanoprost and timolol in patients with open-angle glaucoma or ocular hypertension

    OpenAIRE

    2014-01-01

    Purvi Bhagat,1 Kalyani Sodimalla,2 Chandrima Paul,3 Surinder S Pandav,4 Ganesh V Raman,5 Rengappa Ramakrishnan,6 Abhijeet Joshi,7 Atul Raut7 1Glaucoma Clinic, M & J Western Regional Institute of Ophthalmology, Civil Hospital, Ahmedabad, Gujarat, India; 2Glaucoma Department, PBMA’s H.V. Desai Eye Hospital, Maharashtra, India; 3Glaucoma Service, B B Eye Foundation, Kolkata, India; 4Advanced Eye Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, Indi...

  5. Studies Update Vinyl Chloride Hazards.

    Science.gov (United States)

    Rawls, Rebecca

    1980-01-01

    Extensive study affirms that vinyl chloride is a potent animal carcinogen. Epidemiological studies show elevated rates of human cancers in association with extended contact with the compound. (Author/RE)

  6. Parameters Affecting Hydrogen Chloride Measurements

    Science.gov (United States)

    1993-06-01

    contain sea salt, which is hygroscopic because of the magnesium chloride present, or ammonium bisulfate , which mostly comes from sulfur pollution and is...boosters release hydrogen chloride as a combustion product, and hydrazines or nitric acid can be spilled from liquid fuel motors. Monitoring the...solubility constant, and the second is the acid ionization constant. From experimental work, the product of the two constants is well established (Reference

  7. Chloride channels in stroke

    Institute of Scientific and Technical Information of China (English)

    Ya-ping ZHANG; Hao ZHANG; Dayue Darrel DUAN

    2013-01-01

    Vascular remodeling of cerebral arterioles,including proliferation,migration,and apoptosis of vascular smooth muscle cells (VSMCs),is the major cause of changes in the cross-sectional area and diameter of the arteries and sudden interruption of blood flow or hemorrhage in the brain,ie,stroke.Accumulating evidence strongly supports an important role for chloride (Clˉ) channels in vascular remodeling and stroke.At least three Clˉ channel genes are expressed in VSMCs:1) the TMEM16A (or Ano1),which may encode the calcium-activated Clˉ channels (CACCs); 2) the CLC-3 Clˉ channel and Clˉ/H+ antiporter,which is closely related to the volume-regulated Clˉ channels (VRCCs); and 3) the cystic fibrosis transmembrane conductance regulator (CFTR),which encodes the PKA-and PKC-activated Clˉ channels.Activation of the CACCs by agonist-induced increase in intracellular Ca2+ causes membrane depolarization,vasoconstriction,and inhibition of VSMC proliferation.Activation of VRCCs by cell volume increase or membrane stretch promotes the production of reactive oxygen species,induces proliferation and inhibits apoptosis of VSMCs.Activation of CFTR inhibits oxidative stress and may prevent the development of hypertension.In addition,Clˉ current mediated by gammaaminobutyric acid (GABA) receptor has also been implicated a role in ischemic neuron death.This review focuses on the functional roles of Clˉ channels in the development of stroke and provides a perspective on the future directions for research and the potential to develop Clˉ channels as new targets for the prevention and treatment of stroke.

  8. 21 CFR 184.1138 - Ammonium chloride.

    Science.gov (United States)

    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....

  9. Photonic crystal fiber based chloride chemical sensors for corrosion monitoring

    Science.gov (United States)

    Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar

    2016-04-01

    Corrosion of steel is one of the most important durability issues in reinforced concrete (RC) structures because aggressive ions such as chloride ions permeate concrete and corrode steel, consequently accelerating the destruction of structures, especially in marine environments. There are many practical methods for corrosion monitoring in RC structures, mostly focusing on electrochemical-based sensors for monitoring the chloride ion which is thought as one of the most important factors resulting in steel corrosion. In this work, we report a fiber-optic chloride chemical sensor based on long period gratings inscribed in a photonic crystal fiber (PCF) with a chloride sensitive thin film. Numerical simulation is performed to determine the characteristics and resonance spectral response versus the refractive indices of the analyte solution flowing through into the holes in the PCF. The effective refractive index of the cladding mode of the LPGs changes with variations of the analyte solution concentration, resulting in a shift of the resonance wavelength, hence providing the sensor signal. This fiber-optic chemical sensor has a fast response, is easy to prepare and is not susceptible to electromagnetic environment, and can therefore be of use for structural health monitoring of RC structures subjected to such aggressive environments.

  10. 46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and...

  11. 40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

    Science.gov (United States)

    2010-07-01

    ... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene...

  12. Antimicrobial Effect of An Essential Oil Blend on Surface-attached Salmonella on Polyvinyl Chloride

    Science.gov (United States)

    Polyvinyl chloride (PVC) is basic material for drinking water lines for chickens. Inner surface of PVC pipe can be susceptible to surface-attachment of Salmonella, the 1st stage of biofilm development. Biofilm which can cause Salmonella infection to chickens are known to have great resistance agains...

  13. Dielectric relaxation losses in lead chloride and lead bromide: Localized dipoles

    NARCIS (Netherlands)

    Brom, W.E. van den; Volger, J.

    1974-01-01

    A further analysis of previous reported measurements of dielectric relaxation losses in lead chloride and lead bromide crystals shows that the dipoles may occupy several energetically different positions, giving rise to localization of the dipoles and anomalous behaviour of the susceptibility. This

  14. Plastics and carcinogenesis: The example of vinyl chloride

    Directory of Open Access Journals (Sweden)

    Paul Wesley Brandt-Rauf

    2012-01-01

    Full Text Available The manufacture, use and disposal of various plastics can pose numerous health risks, including the risk of cancer. A model example of carcinogenic risk from plastics is provided by polyvinyl chloride, since it is composed of the known human carcinogen vinyl chloride (VC. In recent years, much has been learned about the molecular biological pathways of VC carcinogenesis. This has led to molecular epidemiologic studies of VC carcinogenesis in exposed human populations which have identified useful biomarkers of exposure, effect and susceptibility for VC. These studies have in turn provided the basis for new molecular approaches for the prevention and treatment of VC cancers. This model could have much wider applicability for many other carcinogenic exposures and many other human cancers.

  15. EFFECT OF CHLORIDE AND SULFATE CONCENTRATION ON PROBABLITY BASED CORROSION CONTROL FOR LIQUID WASTE TANKS- PART IV

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E.

    2012-08-23

    A series of cyclic potentiodynamic polarization tests was performed on samples of A537 carbon steel in support of a probability-based approach to evaluate the effect of chloride and sulfate on corrosion susceptibility. Testing solutions were chosen to build off previous experimental results from FY07, FY08, FY09 and FY10 to systemically evaluate the influence of the secondary aggressive species, chloride, and sulfate. The FY11 results suggest that evaluating the combined effect of all aggressive species, nitrate, chloride, and sulfate, provides a consistent response for determining corrosion susceptibility. The results of this work emphasize the importance for not only nitrate concentration limits, but also chloride and sulfate concentration limits as well.

  16. Electrochemical Chloride extraction using external electrodes?

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2006-01-01

    Electrochemical methods for the removal of chloride from concrete have been developed and the methods are primarily designed for situations where corrosion has started due to an increased chloride concentration in the vicinity of the reinforcement. In these methods the reinforcement is used...... as the cathode. However, some unwanted side effects can occur, including alkali-silica reaction and in some cases hydrogen embrittlement. It is also suggested also to use electrochemical chloride extraction in a preventive way in constructions where chloride induced corrosion is likely to be a problem after...... a period of time, i.e. remove the chlorides before the chloride front reaches the reinforcement. If the chlorides are removed from outer few centimetres from the surface, the chloride will not reach the reinforcement and cause damage. By using the electrochemical chloride removal in this preventive way...

  17. Multiple Osmotic Stress Responses in Acidihalobacter prosperus Result in Tolerance to Chloride Ions

    Science.gov (United States)

    Dopson, Mark; Holmes, David S.; Lazcano, Marcelo; McCredden, Timothy J.; Bryan, Christopher G.; Mulroney, Kieran T.; Steuart, Robert; Jackaman, Connie; Watkin, Elizabeth L. J.

    2017-01-01

    Extremely acidophilic microorganisms (pH optima for growth of ≤3) are utilized for the extraction of metals from sulfide minerals in the industrial biotechnology of “biomining.” A long term goal for biomining has been development of microbial consortia able to withstand increased chloride concentrations for use in regions where freshwater is scarce. However, when challenged by elevated salt, acidophiles experience both osmotic stress and an acidification of the cytoplasm due to a collapse of the inside positive membrane potential, leading to an influx of protons. In this study, we tested the ability of the halotolerant acidophile Acidihalobacter prosperus to grow and catalyze sulfide mineral dissolution in elevated concentrations of salt and identified chloride tolerance mechanisms in Ac. prosperus as well as the chloride susceptible species, Acidithiobacillus ferrooxidans. Ac. prosperus had optimum iron oxidation at 20 g L−1 NaCl while At. ferrooxidans iron oxidation was inhibited in the presence of 6 g L−1 NaCl. The tolerance to chloride in Ac. prosperus was consistent with electron microscopy, determination of cell viability, and bioleaching capability. The Ac. prosperus proteomic response to elevated chloride concentrations included the production of osmotic stress regulators that potentially induced production of the compatible solute, ectoine uptake protein, and increased iron oxidation resulting in heightened electron flow to drive proton export by the F0F1 ATPase. In contrast, At. ferrooxidans responded to low levels of Cl− with a generalized stress response, decreased iron oxidation, and an increase in central carbon metabolism. One potential adaptation to high chloride in the Ac. prosperus Rus protein involved in ferrous iron oxidation was an increase in the negativity of the surface potential of Rus Form I (and Form II) that could help explain how it can be active under elevated chloride concentrations. These data have been used to create a

  18. Susceptibility to Stress Corrosion Cracking of 254SMO SS

    Directory of Open Access Journals (Sweden)

    De Micheli Lorenzo

    2002-01-01

    Full Text Available The susceptibility to stress corrosion cracking (SCC of solubilized and sensitized 254SMO SS was studied in sodium chloride, and sodium fluoride solutions at 80 °C and sulfuric acid solutions in presence of sodium chloride at 25 °C. The influence of salt concentration, pH values and the addition of thiosulfate was examined. The susceptibility to SCC was evaluated by Slow Strain Rate Tests (SSRT, at 1.5 x 10-6 s-1 strain rate. The behavior of 254SMO was compared to those of AISI 316L SS and Hastelloy C276. 254SMO showed an excellent resistance to SCC in all conditions, except in the more acidic solutions (pH <= 1 where, in the sensitized conditions, intergranular stress corrosion cracking occurred.

  19. Lubiprostone: a chloride channel activator.

    Science.gov (United States)

    Lacy, Brian E; Levy, L Campbell

    2007-04-01

    In January 2006 the Food and Drug Administration approved lubiprostone for the treatment of chronic constipation in men and women aged 18 and over. Lubiprostone is categorized as a prostone, a bicyclic fatty acid metabolite of prostaglandin E1. Lubiprostone activates a specific chloride channel (ClC-2) in the gastrointestinal (GI) tract to enhance intestinal fluid secretion, which increases GI transit and improves symptoms of constipation. This article reviews the role of chloride channels in the GI tract, describes the structure, function, and pharmacokinetics of lubiprostone, and discusses clinically important data on this new medication.

  20. Development of bacterial resistance to biocides and antimicrobial agents as a consequence of biocide usage

    DEFF Research Database (Denmark)

    Seier-Petersen, Maria Amalie

    determined (Manuscript III). The biocides comprised benzalkonium chloride (BC), hydrogen peroxide (HP), sodium hypochlorite (SH), formaldehyde (FH), and caustic soda (NaOH). S. aureus isolates did in general not show reduced susceptibility to the biocides tested. However, a quaternary ammonium compound (QAC...

  1. [Headspace GC/MS analysis of residual vinyl chloride and vinylidene chloride in polyvinyl chloride and polyvinylidene chloride products].

    Science.gov (United States)

    Ohno, Hiroyuki; Mutsuga, Motoh; Kawamura, Yoko; Suzuki, Masako; Aoyama, Taiki

    2005-02-01

    A headspace GC/MS analysis method for the simultaneous determination of residual vinyl chloride (VC) and vinylidene chloride (VDC) in polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) products was developed. A test sample was swelled overnight with N,N-dimethylacetamide in a sealed vial. The vial was incubated for 1 hour at 90 degrees C, then the headspace gas was analyzed by GC/MS using a PLOT capillary column. The recoveries from spiked PVC and PVDC samples were 90.0-112.3% for VC and 85.2-108.3% for VDC. The determination limits were 0.01 microg/g for VC and 0.06/microg/g for VDC, respectively. By this method, VC was detected in two PVC water supply pipes at the levels of 0.61 and 0.01 microg/g. On the other hand, VC and VDC were not detected in any of the food container-packages or toys tested.

  2. 1,5-Diaminotetrazolium chloride

    Directory of Open Access Journals (Sweden)

    Ling-Qiao Meng

    2010-04-01

    Full Text Available The title compound, CH5N6+·Cl−, crystallized with two indepedent 1,5-diaminotetrazolium cations and two independent chloride anions in the asymmetric unit. In the crystal, there are a number of N—H...Cl hydrogen-bonding interactions, which generate a three-dimensional network.

  3. Chloride : The queen of electrolytes?

    NARCIS (Netherlands)

    Berend, Kenrick; van Hulsteijn, Leonard Hendrik; Gans, Rijk O. B.

    2012-01-01

    Background: Channelopathies, defined as diseases that are caused by mutations in genes encoding ion channels, are associated with a wide variety of symptoms and have been documented extensively over the past decade. In contrast, despite the important role of chloride in serum, textbooks in general d

  4. 21 CFR 173.375 - Cetylpyridinium chloride.

    Science.gov (United States)

    2010-04-01

    ... CONSUMPTION Specific Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No... Nutrition's Library, Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or...

  5. Predictive Studies Suggest that the Risk for the Selection of Antibiotic Resistance by Biocides Is Likely Low in Stenotrophomonas maltophilia.

    Directory of Open Access Journals (Sweden)

    María Blanca Sánchez

    Full Text Available Biocides are used without restriction for several purposes. As a consequence, large amounts of biocides are released without any control in the environment, a situation that can challenge the microbial population dynamics, including selection of antibiotic resistant bacteria. Previous work has shown that triclosan selects Stenotrophomonas maltophilia antibiotic resistant mutants overexpressing the efflux pump SmeDEF and induces expression of this pump triggering transient low-level resistance. In the present work we analyze if two other common biocides, benzalkonium chloride and hexachlorophene, trigger antibiotic resistance in S. maltophilia. Bioinformatic and biochemical methods showed that benzalkonium chloride and hexachlorophene bind the repressor of smeDEF, SmeT. Only benzalkonium chloride triggers expression of smeD and its effect in transient antibiotic resistance is minor. None of the hexachlorophene-selected mutants was antibiotic resistant. Two benzalkonium chloride resistant mutants presented reduced susceptibility to antibiotics and were impaired in growth. Metabolic profiling showed they were more proficient than their parental strain in the use of some dipeptides. We can then conclude that although bioinformatic predictions and biochemical studies suggest that both hexachlorophene and benzalkonium chloride should induce smeDEF expression leading to transient S. maltophilia resistance to antibiotics, phenotypic assays showed this not to be true. The facts that hexachlorophene resistant mutants are not antibiotic resistant and that the benzalkonium chloride resistant mutants presenting altered susceptibility to antibiotics were impaired in growth suggests that the risk for the selection (and fixation of S. maltophilia antibiotic resistant mutants by these biocides is likely low, at least in the absence of constant selection pressure.

  6. Predictive Studies Suggest that the Risk for the Selection of Antibiotic Resistance by Biocides Is Likely Low in Stenotrophomonas maltophilia.

    Science.gov (United States)

    Sánchez, María Blanca; Decorosi, Francesca; Viti, Carlo; Oggioni, Marco Rinaldo; Martínez, José Luis; Hernández, Alvaro

    2015-01-01

    Biocides are used without restriction for several purposes. As a consequence, large amounts of biocides are released without any control in the environment, a situation that can challenge the microbial population dynamics, including selection of antibiotic resistant bacteria. Previous work has shown that triclosan selects Stenotrophomonas maltophilia antibiotic resistant mutants overexpressing the efflux pump SmeDEF and induces expression of this pump triggering transient low-level resistance. In the present work we analyze if two other common biocides, benzalkonium chloride and hexachlorophene, trigger antibiotic resistance in S. maltophilia. Bioinformatic and biochemical methods showed that benzalkonium chloride and hexachlorophene bind the repressor of smeDEF, SmeT. Only benzalkonium chloride triggers expression of smeD and its effect in transient antibiotic resistance is minor. None of the hexachlorophene-selected mutants was antibiotic resistant. Two benzalkonium chloride resistant mutants presented reduced susceptibility to antibiotics and were impaired in growth. Metabolic profiling showed they were more proficient than their parental strain in the use of some dipeptides. We can then conclude that although bioinformatic predictions and biochemical studies suggest that both hexachlorophene and benzalkonium chloride should induce smeDEF expression leading to transient S. maltophilia resistance to antibiotics, phenotypic assays showed this not to be true. The facts that hexachlorophene resistant mutants are not antibiotic resistant and that the benzalkonium chloride resistant mutants presenting altered susceptibility to antibiotics were impaired in growth suggests that the risk for the selection (and fixation) of S. maltophilia antibiotic resistant mutants by these biocides is likely low, at least in the absence of constant selection pressure.

  7. Predictive Studies Suggest that the Risk for the Selection of Antibiotic Resistance by Biocides Is Likely Low in Stenotrophomonas maltophilia

    Science.gov (United States)

    Sánchez, María Blanca; Decorosi, Francesca; Viti, Carlo; Oggioni, Marco Rinaldo; Martínez, José Luis; Hernández, Alvaro

    2015-01-01

    Biocides are used without restriction for several purposes. As a consequence, large amounts of biocides are released without any control in the environment, a situation that can challenge the microbial population dynamics, including selection of antibiotic resistant bacteria. Previous work has shown that triclosan selects Stenotrophomonas maltophilia antibiotic resistant mutants overexpressing the efflux pump SmeDEF and induces expression of this pump triggering transient low-level resistance. In the present work we analyze if two other common biocides, benzalkonium chloride and hexachlorophene, trigger antibiotic resistance in S. maltophilia. Bioinformatic and biochemical methods showed that benzalkonium chloride and hexachlorophene bind the repressor of smeDEF, SmeT. Only benzalkonium chloride triggers expression of smeD and its effect in transient antibiotic resistance is minor. None of the hexachlorophene-selected mutants was antibiotic resistant. Two benzalkonium chloride resistant mutants presented reduced susceptibility to antibiotics and were impaired in growth. Metabolic profiling showed they were more proficient than their parental strain in the use of some dipeptides. We can then conclude that although bioinformatic predictions and biochemical studies suggest that both hexachlorophene and benzalkonium chloride should induce smeDEF expression leading to transient S. maltophilia resistance to antibiotics, phenotypic assays showed this not to be true. The facts that hexachlorophene resistant mutants are not antibiotic resistant and that the benzalkonium chloride resistant mutants presenting altered susceptibility to antibiotics were impaired in growth suggests that the risk for the selection (and fixation) of S. maltophilia antibiotic resistant mutants by these biocides is likely low, at least in the absence of constant selection pressure. PMID:26201074

  8. Progress of Carbonation in Chloride Contaminated Concretes

    OpenAIRE

    Wang, Yaocheng; Basheer, P. A.M.; Nanukuttan, S; Bai, Y.

    2016-01-01

    Concretes used in marine environment are generally under the cyclic effect of CO2 and chloride ions (Cl-). To date, the influence of carbonation on ingress of chloride ions in concretes has been widely studied; in comparison, study on the influence of Cl- on the progress of carbonation is limited. During the study, concretes were exposed to independent and combined mechanisms of carbonation and chloride ingress regimes. Profiles of apparent pH and chloride concentration were used to indicate ...

  9. Microbial reductive dehalogenation of vinyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Spormann, Alfred M [Stanford, CA; Muller, Jochen A [Baltimore, MD; Rosner, Bettina M [Berlin, DE; Von Abendroth, Gregory [Mannheim, DE; Meshulam-Simon, Galit [Los Angeles, CA; McCarty, Perry L [Stanford, CA

    2014-02-11

    Compositions and methods are provided that relate to the bioremediation of chlorinated ethenes, particularly the bioremediation of vinyl chloride by Dehalococcoides-like organisms. An isolated strain of bacteria, Dehalococcoides sp. strain VS, that metabolizes vinyl chloride is provided; the genetic sequence of the enzyme responsible for vinyl chloride dehalogenation; methods of assessing the capability of endogenous organisms at an environmental site to metabolize vinyl chloride; and a method of using the strains of the invention for bioremediation.

  10. MR susceptibility imaging

    Science.gov (United States)

    Duyn, Jeff

    2013-04-01

    This work reviews recent developments in the use of magnetic susceptibility contrast for human MRI, with a focus on the study of brain anatomy. The increase in susceptibility contrast with modern high field scanners has led to novel applications and insights into the sources and mechanism contributing to this contrast in brain tissues. Dedicated experiments have demonstrated that in most of healthy brain, iron and myelin dominate tissue susceptibility variations, although their relative contribution varies substantially. Local variations in these compounds can affect both amplitude and frequency of the MRI signal. In white matter, the myelin sheath introduces an anisotropic susceptibility that has distinct effects on the water compartments inside the axons, between the myelin sheath, and the axonal space, and renders their signals dependent on the angle between the axon and the magnetic field. This offers opportunities to derive tissue properties specific to these cellular compartments.

  11. 21 CFR 184.1426 - Magnesium chloride.

    Science.gov (United States)

    2010-04-01

    ... mineral bischofite. It is prepared by dissolving magnesium oxide, hydroxide, or carbonate in aqueous... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium chloride. 184.1426 Section 184.1426 Food... Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a) Magnesium chloride (MgC12·6H2O,...

  12. Cystic Fibrosis (CF): Chloride Sweat Test

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Cystic Fibrosis (CF) Chloride Sweat Test KidsHealth > For Parents > Cystic Fibrosis (CF) Chloride Sweat Test Print A A A ... It Is A chloride sweat test helps diagnose cystic fibrosis (CF) , an inherited disorder that makes kids sick ...

  13. 75 FR 33824 - Barium Chloride From China

    Science.gov (United States)

    2010-06-15

    ... COMMISSION Barium Chloride From China Determination On the basis of the record\\1\\ developed in the subject... order on barium chloride from China would be likely to lead to continuation or recurrence of material... Barium Chloride from China: Investigation No. 731-TA-149 (Third Review). By order of the...

  14. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Notice of... chloride from China. SUMMARY: The Commission hereby gives notice that it will proceed with a full review... revocation of the antidumping duty order on barium chloride from China would be likely to lead...

  15. 21 CFR 172.180 - Stannous chloride.

    Science.gov (United States)

    2010-04-01

    ... Preservatives § 172.180 Stannous chloride. The food additive stannous chloride may be safely used for color... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Stannous chloride. 172.180 Section 172.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  16. Oxomemazine hydro­chloride

    OpenAIRE

    Siddegowda, M. S.; Butcher, Ray J.; Mehmet Akkurt; 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...π interactions.

  17. Shock compression of polyvinyl chloride

    Science.gov (United States)

    Neogi, Anupam; Mitra, Nilanjan

    2016-04-01

    This study presents shock compression simulation of atactic polyvinyl chloride (PVC) using ab-initio and classical molecular dynamics. The manuscript also identifies the limits of applicability of classical molecular dynamics based shock compression simulation for PVC. The mechanism of bond dissociation under shock loading and its progression is demonstrated in this manuscript using the density functional theory based molecular dynamics simulations. The rate of dissociation of different bonds at different shock velocities is also presented in this manuscript.

  18. Developing chloride resisting concrete using PFA

    Energy Technology Data Exchange (ETDEWEB)

    Dhir, R.K.; El-Mohr, M.A.K.; Dyer, T.D. [Univ. of Dundee (United Kingdom). Dept. of Civil Engineering

    1997-11-01

    PFA concrete mixes were designed to optimize resistance to chloride ingress. Chloride binding capacity, intrinsic permeability and their concomitant influence on the coefficient of chloride diffusion have been investigated. PFA replacements up to 67% and exposure concentrations of 0.1, 0.5, 1.0 and 5.0 mole/liter were used. Chloride binding capacity was found to increase with increasing PFA replacement up to 50% and to then decline. It increased with chloride exposure concentration as well as water/binder ratio. The coefficient of chloride diffusion of concrete samples was found to be dependent on both the intrinsic permeability of the concrete and the ability of its cement matrix to bind chlorides.

  19. Salt, chloride, bleach, and innate host defense.

    Science.gov (United States)

    Wang, Guoshun; Nauseef, William M

    2015-08-01

    Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense.

  20. Drug: D08811 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D08811 Mixture, Drug Dicyclohexyl ammonium nitrite - benzalkonium chloride mixt; Lades A (TN) Dicyclohexyl...agents 732 Germicides and disinfectants 7324 Invert soaps D08811 Dicyclohexyl ammonium nitrite - benzalkonium chloride mixt PubChem: 96025494 ...

  1. Dermatophyte susceptibility varies towards antimicrobial textiles.

    Science.gov (United States)

    Hammer, Timo R; Mucha, Helmut; Hoefer, Dirk

    2012-07-01

    Dermatophytoses are a widespread problem worldwide. Textiles in contact with infected skin can serve as a carrier for fungus propagation. Hitherto, it is unknown, whether antifungal textiles could contribute in controlling dermatophytes e.g. by disrupting the chain of infection. Testing of antimicrobial fabrics for their antifungal activities therefore is a fundamental prerequisite to assess the putative clinical relevance of textiles for dermatophyte prevention. Fabrics finished with either didecyldimethylammonium chloride (DDAC), poly-hexamethylenbiguanide, copper and two silver chloride concentrations were tested for their antifungal activity against Trichophyton rubrum, Trichophyton mentagrophytes and Candida albicans. To prove dermatophyte susceptibility towards the textiles, swatches were subjected to DIN EN 14199 (Trichophyton sp.) or DIN EN ISO 20743 (C. albicans) respectively. In addition, samples were embedded, and semi-thin sections were analysed microscopically. While all samples showed a clear inhibition of C. albicans, activity against Trichophyton sp. varied significantly: For example, DDAC completely inhibited T. rubrum growth, whereas T. mentagrophytes growth remained unaffected even in direct contact to the fibres. The results favour to add T. mentagrophytes as a test organism in textile dermatophyte efficacy tests. Microscopic analysis of swatches allowed detailed evaluation of additional parameters like mycelium thickness, density and hyphae penetration depth into the fabric.

  2. Hydrolysis of cupric chloride in aqueous ammoniacal ammonium chloride solutions

    Directory of Open Access Journals (Sweden)

    Limpo, J. L.

    1995-06-01

    Full Text Available Cupric solubility in the CuCl2-NH4Cl-NH3-H2O system for chloride concentrations lower than 4 molal in the temperature range 25-60 °C was studied. The experimental results show that for chloride concentration between 3.0 and 1.0 molal the cupric solubility is determined by the solubility of the cupric hydroxychloride Cu(OH1.5Cl0.5. For a chloride concentration value of 4.0 molal, there are two cupric compounds, the hydroxychloride Cu(OH1.5Cl0.5 or the diammine chloride Cu(NH32Cl2, on which the solubility of Cu(II depends, according to the temperature and the value of the ratio [NH3]Total/[Cu]Total.

    Se estudia la solubilidad del Cu(II en el sistema CuCl2-NH4Cl-NH3-H2O para concentraciones de cloruro inferiores a 4 molal en el intervalo de temperaturas 25-60 °C. Los resultados experimentales muestran que, para concentraciones de cloruros comprendidas entre 3,0 y 1,0 molal, la solubilidad cúprica viene determinada por la solubilidad del hidroxicloruro cúprico, Cu(OH1.5Cl0.5. Para concentraciones de cloruro 4,0 molal, existen dos compuestos cúpricos, el hidroxicloruro, Cu(OH1.5Cl0.5 o el cloruro de diamina, Cu(NH32Cl2, de los que, de acuerdo con la temperatura y con el valor de la relación [NH3]Total/[Cu]Total depende la solubilidad del Cu(II.

  3. Genetic susceptibility of periodontitis

    NARCIS (Netherlands)

    Laine, M.L.; Crielaard, W.; Loos, B.G.

    2012-01-01

    In this systematic review, we explore and summarize the peer-reviewed literature on putative genetic risk factors for susceptibility to aggressive and chronic periodontitis. A comprehensive literature search on the PubMed database was performed using the keywords ‘periodontitis’ or ‘periodontal dise

  4. Oxomemazine hydro­chloride

    Science.gov (United States)

    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⋯π inter­actions. PMID:22090928

  5. Simple chloride sensors for continuous groundwater monitoring

    DEFF Research Database (Denmark)

    Thorn, Paul; Mortensen, John

    2012-01-01

    The development of chloride sensors which can be used for continuous, on-line monitoring of groundwater could be very valuable in the management of our coastal water resources. However, sensor stability, drift, and durability all need to be addressed in order for the sensors to be used...... in continuous application. This study looks at the development of a simple, inexpensive chloride electrode, and evaluates its performance under continuous use, both in the laboratory and in a field test in a monitoring well. The results from the study showed a consistent response to changing chloride...... sensor remained responsive even at low chloride concentrations, where the conductivity electrode was no longer responding to changing chloride levels. With the results, it is believed that the simple chloride sensor could be used for continuous monitoring of groundwater quality....

  6. Chloride Ion Critical Content in Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chloride ion critical content was studied under soaking and cycle of dry and wet conditions,with three electrochemical nondestructive measuring techniques, i e, half-cell potential, A C impedance, and time potential. The experimental results show that chloride ion critical content is primarily determined by the water cement ratio, while for the same concrete mixture the chloride ion critical content in soaking conditions is larger than that in a cycle of dry and wet conditions.

  7. Chloride binding site of neurotransmitter sodium symporters

    DEFF Research Database (Denmark)

    Kantcheva, Adriana Krassimirova; Quick, Matthias; Shi, Lei

    2013-01-01

    Neurotransmitter:sodium symporters (NSSs) play a critical role in signaling by reuptake of neurotransmitters. Eukaryotic NSSs are chloride-dependent, whereas prokaryotic NSS homologs like LeuT are chloride-independent but contain an acidic residue (Glu290 in LeuT) at a site where eukaryotic NSSs...... have a serine. The LeuT-E290S mutant displays chloride-dependent activity. We show that, in LeuT-E290S cocrystallized with bromide or chloride, the anion is coordinated by side chain hydroxyls from Tyr47, Ser290, and Thr254 and the side chain amide of Gln250. The bound anion and the nearby sodium ion...

  8. Chloride ingress in cement paste and mortar

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, O.M.; Hansen, P.F.; Coats, A.M.; Glasser, F.P.

    1999-09-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature). The measurements are modelled on Fick's law modified by a term for chloride binding. Inclusion of chloride binding significantly improves the profile shape of the modelled ingress profiles. The presence of fine aggregate and formation of interfacial transition zones at paste-aggregate boundaries does not significantly affect diffusion rates.

  9. Green process to recover magnesium chloride from residue solution of potassium chloride production plant

    Institute of Scientific and Technical Information of China (English)

    Lin WANG; Yunliang HE; Yanfei WANG; Ying BAO; Jingkang WANG

    2008-01-01

    The green process to recover magnesium chlor-ide from the residue solution of a potassium chloride pro-duction plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The res-idue solution contains magnesium chloride above 25 wt-%, potassium chloride and sodium chloride together below 5 wt-% and a few other ions such as Br-, SO2-4and Ca2+. The recovery process contains two steps: the previous impurity removal operation and the two-stage evapora-tion-cooling crystallization procedure to produce magnes-ium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria.

  10. ENVIRONMENTAL EXPOSURE TO VINYL CHLORIDE

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-09-01

    Full Text Available Vinyl chloride (VC monomer is a wellknown carcinogenic and mutagenic substance causes liver damages, angiosarcoma of the liver, acro – osteolysis, sclerodermalike changes in workers chronically exposed to this gas. There are following VC emitors to the environment: VC production plants, polymerization facilities and planes where polyvinyl products are fabricated. Because of that, the general population is coming into VC contact through polluted air, food and water. VC concentration in all mentioned sites is very low, often not detectable. There was found any health risk for the general population. The VC air concentration in the vicinity to antropogenic emitors is always higher. Such a situation may causes undesirable health effect for residents living in the neighbourhood. Epidemiological studies are performed to detect the adverse VC effect in selected cohorts. Non of the study did not confirmed cases of angiosarcoma among residents living near a vinyl chloride sites. VC production is growing permanently, so VC emission will be higher. Because of that health monitoring of general population and especially of selected groups seems to be necessary in the future.

  11. Efficacy of an alcohol-based healthcare hand rub containing synergistic combination of farnesol and benzethonium chloride.

    Science.gov (United States)

    Shintre, Milind S; Gaonkar, Trupti A; Modak, Shanta M

    2006-09-01

    Healthcare workers are required to disinfect the hands several times a day using hand disinfectants, which leads to chronic hand exposure to high levels of antimicrobials contained in the disinfectants, which could compromise the skin integrity. This problem may be addressed by developing hand disinfectants containing synergistic combinations of small amounts of antimicrobials and other agents. The synergistic effect of farnesol and essential oils with several antimicrobials was studied in vitro to select an effective antimicrobial system in preservative concentration for use in healthcare hand rub. Farnesol and lemon oil showed synergistic activity against S. aureus, in combination with benzalkonium chloride and benzethonium chloride, but not with other antimicrobials studied. All essential oils studied showed synergy with benzethonium chloride against Staphylococcus aureus and Escherichia coli. An alcohol-based healthcare hand rub (ZBF hand rub) containing this unique synergistic combination of farnesol and benzethonium chloride was then developed and its efficacy as a healthcare hand rub was evaluated in human volunteers according to the US FDA-TFM protocol using Serratia marcescens as a marker organism. The ZBF hand rub showed a 3.22 log(10) reduction in the microbial count after the first application and a 5.49 log(10) reduction after the tenth application in vivo and exceeds the US FDA-TFM criteria for healthcare hand rub. The ZBF hand rub did not irritate the hands when tested on human volunteers when applied 10 times everyday for five consecutive days. The ZBF hand rub exhibits more than 5.5 log(10) reduction in the microbial count within 15s and more than 2.8 log(10) reduction in the two types of viruses tested within 30s in vitro. When evaluated in an in vitro pig skin model, the ZBF hand rub shows better prolonged activity (20-35 min post-application) against transient bacteria (S. aureus and E. coli) compared to other alcohol-based hand rubs. These

  12. Genetic Susceptibility to Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Sanja Kovacic

    2012-01-01

    Full Text Available Atherosclerosis is a complex multifocal arterial disease involving interactions of multiple genetic and environmental factors. Advances in techniques of molecular genetics have revealed that genetic ground significantly influences susceptibility to atherosclerotic vascular diseases. Besides further investigations of monogenetic diseases, candidate genes, genetic polymorphisms, and susceptibility loci associated with atherosclerotic diseases have been identified in recent years, and their number is rapidly increasing. This paper discusses main genetic investigations fields associated with human atherosclerotic vascular diseases. The paper concludes with a discussion of the directions and implications of future genetic research in arteriosclerosis with an emphasis on prospective prediction from an early age of individuals who are predisposed to develop premature atherosclerosis as well as to facilitate the discovery of novel drug targets.

  13. Comparing polyaluminum chloride and ferric chloride for antimony removal.

    Science.gov (United States)

    Kang, Meea; Kamei, Tasuku; Magara, Yasumoto

    2003-10-01

    Antimony has been one of the contaminants required to be regulated, however, only limited information has been collected to date regarding antimony removal by polyaluminium chloride (PACl) and ferric chloride (FC). Accordingly, the possible use of coagulation by PACl or FC for antimony removal was investigated. Jar tests were used to determine the effects of solution pH, coagulant dosage, and pre-chlorination on the removal of various antimony species. Although high-efficiency antimony removal by aluminum coagulation has been expected because antimony is similar to arsenic in that both antimony and arsenic are a kind of metalloid in group V of the periodic chart, this study indicated: (1) removal density (arsenic or antimony removed per mg coagulant) for antimony by PACl was about one forty-fifth as low as observed for As(V); (2) although the removal of both Sb(III) and Sb(V) by coagulation with FC was much higher than that of PACl, a high coagulant dose of 10.5mg of FeL(-1) at optimal pH of 5.0 was still not sufficient to meet the standard antimony level of 2 microg as SbL(-1) for drinking water when around 6 microg as SbL(-1) were initially present. Consequently, investigation of a more appropriate treatment process is necessary to develop economical Sb reduction; (3) although previous studies concluded that As(V) is more effectively removed than As(III), this study showed that the removal of Sb(III) by coagulation with FC was much more pronounced than that of Sb(V); (4) oxidation of Sb(III) with chlorine decreased the ability of FC to remove antimony. Accordingly, natural water containing Sb(III) under anoxic condition should be coagulated without pre-oxidation.

  14. Electrochemical Behavior of Copper in Thionyl Chloride Solutions.

    Science.gov (United States)

    1980-12-01

    lithium - thionyl chloride batteries . Thionyl chloride is known *3 to react...electrolyte for lithium - thionyl chloride batteries . 8R. K. McAlpine and B. A. Soule, Prescott and Johnson’s Qualitative Chemical Analysis, D. Van...black carbon electrodes, cupric chloride appears to be a useful cathode additive for lithium - thionyl chloride batteries . Preliminary results2l

  15. Effect of Ammonium Molybdate Inhibition on Corrosion Behaviour of Mild Steel in Chloride and Sulphide Media

    Directory of Open Access Journals (Sweden)

    Ayo S. Afolabi

    2010-10-01

    Full Text Available The corrosion inhibition of mild steel in 3.0 M sodium chloride and 0.5 M sodium sulphide using various concentrations of ammonium molybdate was investigated in this work. The inhibition effect of this reagent in these media was monitored by weight loss and pH measurements. The analyses of the weight loss results showed that the corrosion susceptibility of mild steel in 3.0 M sodium chloride was more pronounced than in 0.5 M of sodium sulphide due to the aggressive chloride ions in the former and the weak nature of the latter. Ammonium molybdate produced a better inhibition performance of mild steel in 0.5 M sodium suphide than in 3.0 M sodium chloride medium and the higher the concentration of ammonium molybdate the more the inhibition performance on mild steel in the media studied. Optimum inhibition was obtained at 2.5 M ammonium molybdate in both media. The pH values in chloride medium remained acidic throughout the exposure period while those of sulphide medium shifted to alkaline region with exposure time; an effect that was traceable to higher inhibition obtained in the latter medium.

  16. Chronopotentiometric chloride sensing using transition time measurement

    NARCIS (Netherlands)

    Abbas, Y.; Graaf, de D.B.; Olthuis, W.; Berg, van den A.

    2013-01-01

    Detection of chloride ions is crucial to accurately access the concrete structure durability[1]. The existing electrochemical method of chloride ions detection in concrete, potentiometry[1], is not suitable for in-situ measurement due to the long term stability issue of conventional reference electr

  17. 29 CFR 1915.1017 - Vinyl chloride.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Vinyl chloride. 1915.1017 Section 1915.1017 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... § 1915.1017 Vinyl chloride. Note: The requirements applicable to shipyard employment under this...

  18. 29 CFR 1926.1117 - Vinyl chloride.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Vinyl chloride. 1926.1117 Section 1926.1117 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1117 Vinyl chloride. Note: The requirements applicable to construction work under this section are identical to...

  19. Chemische contaminanten in diervoeder additief Choline Chloride

    NARCIS (Netherlands)

    Traag, W.A.; Hoogenboom, L.A.P.; Jong, de J.; Egmond, van H.J.; Dam, ten G.

    2010-01-01

    Dit briefrapport beschrijft de resultaten van een onderzoek naar chemische contaminanten in Choline Chloride. De doelstellingen waren: 1) Inzicht te verkrijgen in het voorkomen van (gebromeerde) vlamvertragers en broomdioxines in het diervoederadditief Choline Chloride en het, op basis van de result

  20. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements...

  1. Drug: D00857 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D00857 Drug Benzalkonium chloride (JP16/NF/INN); Zephiran chloride (TN) C9H13NR. Cl... individual organs 26 Epidermides 261 Antimicrobial agents 2616 Medical soaps D00857 Benzalkonium...732 Germicides and disinfectants 7324 Invert soaps D00857 Benzalkonium chloride (JP16/NF/INN) Anatomical The...TICS AND DISINFECTANTS D08A ANTISEPTICS AND DISINFECTANTS D08AJ Quaternary ammonium compounds D08AJ01 Benzalkonium D00857 Benzalkoniu...icated dressings with antiinfectives D09AA11 Benzalkonium D00857 Benzalkonium chl

  2. Aqueous sodium chloride induced intergranular corrosion of Al-Li-Cu alloys

    Science.gov (United States)

    Pizzo, P. P.; Daeschner, D. L.

    1986-01-01

    Two methods have been explored to assess the susceptibility of Al-Li-Cu alloys to intergranular corrosion in aqueous sodium chloride solution. They are: (1) constant extension rate testing with and without alternate-immersion preexposure and (2) metallographic examination after exposure to a NaCl-H2O2 corrosive solution per Mil-H-6088F. Intergranular corrosion was found to occur in both powder and ingot metallurgy alloys of similar composition, using both methods. Underaging rendered the alloys most susceptible. The results correlate to stress-corrosion data generated in conventional time-to-failure and crack growth-rate tests. Alternate-immersion preexposure may be a reliable means to assess stress corrosion susceptibility of Al-Li-Cu alloys.

  3. Chloride Transport in Undersea Concrete Tunnel

    Directory of Open Access Journals (Sweden)

    Yuanzhu Zhang

    2016-01-01

    Full Text Available Based on water penetration in unsaturated concrete of underwater tunnel, a diffusion-advection theoretical model of chloride in undersea concrete tunnel was proposed. The basic parameters including porosity, saturated hydraulic conductivity, chloride diffusion coefficient, initial water saturation, and moisture retention function of concrete specimens with two water-binder ratios were determined through lab-scale experiments. The variation of chloride concentration with pressuring time, location, solution concentration, initial saturation, hydraulic pressure, and water-binder ratio was investigated through chloride transport tests under external water pressure. In addition, the change and distribution of chloride concentration of isothermal horizontal flow were numerically analyzed using TOUGH2 software. The results show that chloride transport in unsaturated concrete under external water pressure is a combined effect of diffusion and advection instead of diffusion. Chloride concentration increased with increasing solution concentration for diffusion and increased with an increase in water pressure and a decrease in initial saturation for advection. The dominant driving force converted with time and saturation. When predicting the service life of undersea concrete tunnel, it is suggested that advection is taken into consideration; otherwise the durability tends to be unsafe.

  4. Chloride Ingress into Concrete under Water Pressure

    OpenAIRE

    Lund, Mia Schou; Sander, Lotte Braad; Grelk, Bent; Hansen, Kurt Kielsgaard

    2011-01-01

    The chloride ingress into concrete under water pressures of 100 kPa and 800 kPa have been investigated by experiments. The specimens were exposed to a 10% NaCl solution and water mixture. For the concrete having w/c = 0.35 the experimental results show the chloride diffusion coefficient at 800 kPa (~8 atm.) is 12 times greater than at 100 kPa (~1 atm.). For w/c = 0.45 and w/c = 0.55 the chloride diffusion coefficients are 7 and 3 times greater. This means that a change in pressure highly infl...

  5. Reliability-Based Planning of Chloride Measurements

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Engelund, S.

    1996-01-01

    on measurements of the chloride content obtained from the given structure. In the present paper optimal planning of measurements of the chloride content in reinforced concrete structures is considered. It is shown how optimal experimental plans can be obtained using FORM-analysis. Bayesian statistics are used......In reinforced concrete structures corrosion is initiated when the chloride concentration around the reinforcement exceeds a threshold value. If corrosion starts then expensive repairs can be necessary. The estimation of the probability that corrosion has been initiated in a given structure is based...

  6. Network susceptibilities: Theory and applications

    Science.gov (United States)

    Manik, Debsankha; Rohden, Martin; Ronellenfitsch, Henrik; Zhang, Xiaozhu; Hallerberg, Sarah; Witthaut, Dirk; Timme, Marc

    2017-01-01

    We introduce the concept of network susceptibilities quantifying the response of the collective dynamics of a network to small parameter changes. We distinguish two types of susceptibilities: vertex susceptibilities and edge susceptibilities, measuring the responses due to changes in the properties of units and their interactions, respectively. We derive explicit forms of network susceptibilities for oscillator networks close to steady states and offer example applications for Kuramoto-type phase-oscillator models, power grid models, and generic flow models. Focusing on the role of the network topology implies that these ideas can be easily generalized to other types of networks, in particular those characterizing flow, transport, or spreading phenomena. The concept of network susceptibilities is broadly applicable and may straightforwardly be transferred to all settings where networks responses of the collective dynamics to topological changes are essential.

  7. Susceptibility to anchoring effects

    Directory of Open Access Journals (Sweden)

    Todd McElroy

    2007-02-01

    Full Text Available Previous research on anchoring has shown this heuristic to be a very robust psychological phenomenon ubiquitous across many domains of human judgment and decision-making. Despite the prevalence of anchoring effects, researchers have only recently begun to investigate the underlying factors responsible for how and in what ways a person is susceptible to them. This paper examines how one such factor, the Big-Five personality trait of openness-to-experience, influences the effect of previously presented anchors on participants' judgments. Our findings indicate that participants high in openness-to-experience were significantly more influenced by anchoring cues relative to participants low in this trait. These findings were consistent across two different types of anchoring tasks providing convergent evidence for our hypothesis.

  8. Topological Susceptibility from Slabs

    CERN Document Server

    Bietenholz, Wolfgang; Gerber, Urs

    2015-01-01

    In quantum field theories with topological sectors, a non-perturbative quantity of interest is the topological susceptibility chi_t. In principle it seems straightforward to measure chi_t by means of Monte Carlo simulations. However, for local update algorithms and fine lattice spacings, this tends to be difficult, since the Monte Carlo history rarely changes the topological sector. Here we test a method to measure chi_t even if data from only one sector are available. It is based on the topological charges in sub-volumes, which we denote as slabs. Assuming a Gaussian distribution of these charges, this method enables the evaluation of chi_t, as we demonstrate with numerical results for non-linear sigma-models.

  9. Mitigation of chloride and sulfate based corrosion in reinforced concrete via electrokinetic nanoparticle treatment

    Science.gov (United States)

    Kupwade-Patil, Kunal

    Concrete is a porous material which is susceptible to the migration of highly deleterious species such as chlorides and sulfates. Various external sources, including sea salt spray, direct seawater wetting, deicing salts and chlorides can contaminate reinforced concrete. Chlorides diffuse into the capillary pores of concrete and come into contact with the reinforcement. When chloride concentration at the reinforcement exceeds a threshold level it breaks down the passive oxide layer, leading to chloride induced corrosion. The application of electrokinetics using positively charged nanoparticles for corrosion protection in reinforced concrete structures is an emerging technology. This technique involves the principle of electrophoretic migration of nanoparticles to hinder chloride diffusion in the concrete. The return of chlorides is inhibited by the electrodeposited assembly of the nanoparticles at the reinforcement interface. This work examined the nanoparticle treatment impact on chloride and sulfate induced corrosion in concrete. Electrokinetic Nanoparticle (EN) treatments were conducted on reinforced cylindrical concrete, rectangular ASTM G109 specimens that simulate a bridge deck and full scale beam specimens. EN treatment to mitigate external sulfate attack in concrete was performed on cylindrical concrete specimens. Corrosion results indicated lower corrosion potentials and rates as compared to the untreated specimens. Scanning electron microscopy (SEM) showed a dense microstructure within the EN treated specimens. Chemical analysis (Raman spectroscopy, X ray-diffraction, and Fourier transform infrared spectroscopy FTIR) showed the presence of strength enhancing phases such as calcium aluminate hydrate (C-A-H) and increased amounts of calcium silicate hydrate (C-S-H) within the EN treated specimens. Strength and porosity results showed an increase in strength and a reduction in porosity among the EN treated specimens. EN treatment acted as a protective

  10. Catastrophic event modeling. [lithium thionyl chloride batteries

    Science.gov (United States)

    Frank, H. A.

    1981-01-01

    A mathematical model for the catastrophic failures (venting or explosion of the cell) in lithium thionyl chloride batteries is presented. The phenomenology of the various processes leading to cell failure is reviewed.

  11. Surface adsorption in strontium chloride ammines

    DEFF Research Database (Denmark)

    Ammitzbøll, Andreas L.; Lysgaard, Steen; Klukowska, Agata

    2013-01-01

    An adsorbed state and its implications on the ab- and desorption kinetics of ammonia in strontium chloride ammine is identified using a combination of ammonia absorption measurements, thermogravimetric analysis, and density functional theory calculations. During thermogravimetric analysis, ammoni...

  12. Qualitative Determination of Nitrate with Triphenylbenzylphosphonium Chloride.

    Science.gov (United States)

    Berry, Donna A.; Cole, Jerry J.

    1984-01-01

    Discusses two procedures for the identification of nitrate, the standard test ("Brown Ring" test) and a new procedure using triphenylbenzylphosphonium chloride (TPBPC). Effectiveness of both procedures is compared, with the TPBPC test proving to be more sensitive and accurate. (JM)

  13. Chloride Ingress into Concrete under Water Pressure

    DEFF Research Database (Denmark)

    Lund, Mia Schou; Sander, Lotte Braad; Grelk, Bent;

    2011-01-01

    The chloride ingress into concrete under water pressures of 100 kPa and 800 kPa have been investigated by experiments. The specimens were exposed to a 10% NaCl solution and water mixture. For the concrete having w/c = 0.35 the experimental results show the chloride diffusion coefficient at 800 k......Pa (~8 atm.) is 12 times greater than at 100 kPa (~1 atm.). For w/c = 0.45 and w/c = 0.55 the chloride diffusion coefficients are 7 and 3 times greater. This means that a change in pressure highly influences the chloride ingress into the concrete and thereby the life length models for concrete structures....

  14. 75 FR 20625 - Barium Chloride From China

    Science.gov (United States)

    2010-04-20

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject review. DATES: Effective Date: April 9, 2010. FOR FURTHER INFORMATION CONTACT:...

  15. Telomerization of Vinyl Chloride with Chloroform Initiated by Ferrous Chloride-Dimethylacetamide under Ultrasonic Conditions

    Directory of Open Access Journals (Sweden)

    Hua Qian

    2015-01-01

    Full Text Available Telomerization of vinyl chloride with chloroform was investigated using ferrous chloride-dimethylacetamide system, and 42.1% yield, more than four times the one reported before, was achieved. The addition of ultrasound further improved the reaction and yield was raised to 51.9% with trace byproducts at highly reduced reaction time and temperature. Ferrous chloride-dimethylacetamide under ultrasonic irradiation acts as a very efficient catalyst system for the 1 : 1 telomerization.

  16. Cesium chloride-induced torsades de pointes

    OpenAIRE

    Wiens, Matthew; Gordon, Wendy; Baulcomb, Daisy; Mattman, Andre; Mock, Tom; Brown, Robert

    2009-01-01

    The chloride salt of cesium, a group 1A element, is gaining popularity as an alternative treatment of advanced cancers. Cesium chloride has primarily been used in cardiovascular research for arrhythmogenesis in animals because of its potassium-blocking effects. The present report describes a 45-year-old woman with metastatic breast cancer who experienced repeated episodes of torsades de pointes polymorphic ventricular tachycardia after several months of oral cesium therapy. There was a clear ...

  17. The kinetics of the hydrogen chloride oxidation

    Directory of Open Access Journals (Sweden)

    Gonzalez Martinez Isai

    2013-01-01

    Full Text Available Hydrogen chloride (HCl oxidation has been investigated on technical membrane electrode assemblies in a cyclone flow cell. Influence of Nafion loading, temperature and hydrogen chloride mole fraction in the gas phase has been studied. The apparent kinetic parameters like reaction order with respect to HCl, Tafel slope and activation energy have been determined from polarization data. The apparent kinetic parameters suggest that the recombination of adsorbed Cl intermediate is the rate determining step.

  18. Effect of Chloride Type on Penetration of Chloride Ions in Concrete

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The influence of chloride type on the diffusivity of chloride ions in concrete was studied by experiment. The result shows that the glectric resistance of concrete and the chloride diffusion coefficient are influenced by chloride type. For the same water/cement ratio (W/C), the diffusion coefficient D in KCl solution is larger than that in NaCl solution; however, the concrete resistance in KCl solution is smaller than that in NaCl solution. The experimental result is analyzed with theory of diffusion.

  19. Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

    Directory of Open Access Journals (Sweden)

    Gai-Fei Peng

    2014-04-01

    Full Text Available The influence of a chloride-ion adsorption agent (Cl agent in short, composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage of 6% by mass of cementitious materials in mortar, the resistance to the penetration of chloride ions could be improved greatly, which was more pronounced when a combination of the Cl agent and fly ash or slag was employed. Such an effect is not the result of the low permeability of the mortar, but might be a result of the interaction between the Cl agent and the chloride ions penetrated into the mortar. There are two possible mechanisms for the interaction between the Cl agent and chloride ion ingress. One is the reaction between calcium aluminate hydrate in the Cl agent and chloride ions to form Friedel’s salt, and the other one is that calcium aluminate hydrate reacts with calcium nitrite to form AFm during the early-age hydration of mortar and later the NO2− in AFm is replaced by chloride ions, which then penetrate into the mortar, also forming Friedel’s salt. More research is needed to confirm the mechanisms.

  20. 42 CFR 84.250 - Vinyl chloride respirators; description.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Vinyl chloride respirators; description. 84.250... Respirators § 84.250 Vinyl chloride respirators; description. Vinyl chloride respirators, including all... escape from vinyl chloride atmospheres containing adequate oxygen to support life, are...

  1. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2009-09-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many coastal areas of Australia, may have perturbed catchment chloride balance conditions for appropriate use in CMB applications. In order to deal with these issues, a high resolution chloride deposition map in the coastal region is needed. In this study, we examined geographic, orographic, and atmospheric factors influencing chloride deposition in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia, using partial correlation and regression analyses. The results indicate that coastal distance, and terrain aspect and slope are two most significant factors controlling chloride deposition. Coastal distance accounts for 65% spatial variability in chloride deposition, with terrain aspect and slope for 8%. The deposition gradient is about 0.08 gm-2 year-1 km-1 as one progresses inland. The results are incorporated into a published de-trended residual kriging approach (ASOADeK to produce a 1 km×1 km resolution annual chloride deposition map and a bulk precipitation chloride concentration map. The average uncertainty of the deposition map is about 30% in the western MLR, and over 50% in the eastern MLR. The maps will form a very useful basis for examining catchment chloride balances for use in the CMB application in the study area.

  2. A comprehensive probabilistic model of chloride ingress in unsaturated concrete

    OpenAIRE

    Bastidas-Arteaga, Emilio; Chateauneuf, Alaa; Sánchez-Silva, Mauricio; Bressolette, Philippe; Schoefs, Franck

    2011-01-01

    International audience; Corrosion induced by chloride ions has become a critical issue for many reinforced concrete structures. The chloride ingress into concrete has been usually simplified as a diffusion problem where the chloride concentration throughout concrete is estimated analytically. However, this simplified approach has several limitations. For instance, it does not consider chloride ingress by convection which is essential to model chloride penetration in unsaturated conditions as ...

  3. Corrosion Behavior of Alloy 22 in Oxalic Acid and Sodium Chloride Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Day, S D; Whalen, M T; King, K J; Hust, G A; Wong, L L; Estill, J C; Rebak, R B

    2003-06-24

    Nickel based Alloy 22 (NO6022) is extensively used in aggressive industrial applications, especially due to its resistance to localized corrosion and stress corrosion cracking in high chloride environments. The purpose of this work was to characterize the anodic behavior of Alloy 22 in oxalic acid solution and to compare its behavior to sodium chloride (NaCl) solutions. Standard electrochemical tests such as polarization resistance and cyclic polarization were used. Results show that the corrosion rate of Alloy 22 in oxalic acid solutions increased rapidly as the temperature and the acid concentration increased. Extrapolation studies show that even at a concentration of 10{sup -4}M oxalic acid, the corrosion rate of Alloy 22 would be higher in oxalic acid than in 1 M NaCl solution. Alloy 22 was not susceptible to localized corrosion in oxalic acid solutions. Cyclic polarization tests in 1 M NaCl showed that Alloy 22 was susceptible to crevice corrosion at 90 C but was not susceptible at 60 C.

  4. Effects of applied potential on the stress corrosion cracking behavior of 7003 aluminum alloy in acid and alkaline chloride solutions

    Science.gov (United States)

    Zhang, Xiao-yan; Song, Ren-guo; Sun, Bin; Lu, Hai; Wang, Chao

    2016-07-01

    Potentiodynamic polarization tests and slow strain rate test (SSRT) in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking (SCC) behavior of 7003 aluminum alloy (AA7003) in acid and alkaline chloride solutions under various applied potentials ( E a). The results show that AA7003 is to a certain extent susceptible to SCC via anodic dissolution (AD) at open-circuit potential (OCP) and is highly susceptible to hydrogen embrittlement (HE) at high negative E a in the solutions with pH levels of 4 and 11. The susceptibility increases with negative shift in the potential when E a is less than -1000 mV vs. SCE. However, the susceptibility distinctly decreases because of the inhibition of AD when E a is equal to -1000 mV vs. SCE. In addition, the SCC susceptibility of AA7003 in the acid chloride solution is higher than that in the alkaline solution at each potential. Moreover, the effect of hydrogen on SCC increases with increasing hydrogen ion concentration.

  5. Inhibition of nitrite-induced toxicity in channel catfish by calcium chloride and sodium chloride

    Science.gov (United States)

    Tommasso J.R., Wright; Simco, B.A.; Davis, K.B.

    1980-01-01

    Environmental chloride has been shown to inhibit methemoglobin formation in fish, thereby offering a protective effect against nitrite toxicity. Channel catfish (Ictalurus punctatus) were simultaneously exposed to various environmental nitrite and chloride levels (as either CaCl2 or NaCl) in dechlorinated tap water (40 mg/L total hardness, 47 mg/L alkalinity, 4 mg/L chloride, pH = 6.9-7.1, and temperature 21-24°C). Methemoglobin levels in fish simultaneously exposed to 2.5 mg/L nitrite and up to 30 mg/L chloride as either CaCl2 or NaCl were similar but significantly lower than in unprotected fish. Exposure to 10 mg/L nitrite and 60 mg/L chloride resulted in methemoglobin levels similar to those of the controls; most unprotected fish died. Fish exposed to 10 mg/L nitrite had significantly lower methemoglobin levels when protected with 15.0 mg/L chloride as CaCl2 than with NaCl. Fish exposed to nitrite in the presence of 60 mg/L chloride (as either CaCl2 or NaCl) had similar 24-h LC50 values that were significantly elevated above those obtained in the absence of chloride. Calcium had little effect on tolerance to nitrite toxicity in channel catfish in contrast to its large effect reported in steelhead trout (Salmo gairdneri).

  6. Congenital Chloride Diarrhea: Diagnosis by Easy-Accessible Chloride Measurement in Feces

    Directory of Open Access Journals (Sweden)

    C. Gils

    2016-01-01

    Full Text Available Background. Congenital chloride diarrhea (CCD is an autosomal recessive disorder caused by mutations in the genes encoding the intestinal Cl−/HCO3- exchanger and is clinically characterized by watery, profound diarrhea, electrolyte disturbances, and metabolic alkalosis. The CCD diagnosis is based on the clinical symptoms and measurement of high chloride concentration in feces (>90 mmol/L and is confirmed by DNA testing. Untreated CCD is lethal, while long-term clinical outcome improves when treated correctly. Case Presentation. A 27-year-old woman had an emergency caesarian due to pain and discomfort in gestational week 36 + 4. The newborn boy had abdominal distension and yellow fluid per rectum. Therapy with intravenous glucose and sodium chloride decreased his stool frequency and improved his clinical condition. A suspicion of congenital chloride diarrhea was strongly supported using blood gas analyzer to measure an increased chloride concentration in the feces; the diagnosis was confirmed by DNA testing. Discussion. Measurement of chloride in feces using an ordinary blood gas analyzer can serve as a preliminary analysis when congenital chloride diarrhea is suspected. This measurement can be easily performed with a watery feces composition. An easy-accessible chloride measurement available will facilitate the diagnostics and support the initial treatment if CCD is suspected.

  7. Amine and Titanium (IV Chloride, Boron (III Chloride or Zirconium (IV Chloride-Promoted Baylis-Hillman Reactions

    Directory of Open Access Journals (Sweden)

    Shi-Cong Cui

    2001-10-01

    Full Text Available The Baylis-Hillman reactions of various aryl aldehydes with methyl vinyl ketone at temperatures below -20oC using Lewis acids such as titanium (IV chloride, boron (III chloride or zirconium (IV chloride in the presence of a catalytic amount of selected amines used as a Lewis bases afford the chlorinated compounds 1 as the major product in very high yields. Acrylonitrile can also undergo the same reaction to give the corresponding chlorinated product in moderate yield. A plausible reaction mechanism is proposed. However, if the reaction was carried out at room temperature (ca. 20oC, then the Z-configuration of the elimination product 3, derived from 1, was formed as the major product.

  8. Gadolinium chloride reduces cytochrome P450: relevance to chemical-induced hepatotoxicity.

    Science.gov (United States)

    Badger, D A; Kuester, R K; Sauer, J M; Sipes, I G

    1997-08-15

    The Kupffer cell inhibitor, gadolinium chloride (GdCl3), protects the liver from a number of toxicants that require biotransformation to elicit toxicity (i.e. 1,2-dichlorobenzene and CCl4), as well as compounds that do not (i.e. cadmium chloride and beryllium sulfate). The mechanism of this protection is thought to result from reduced secretion of inflammatory and cytotoxic products from Kupffer cells (KC). However, since other lanthanides have been shown to decrease cytochrome P450 (P450) activity, the following studies were designed to determine if GdCl3 pretreatment alters hepatic P450 levels or activity. The toxicological relevance of GdCl3-mediated alterations in P450 activity was also estimated by determining the effect of GdCl3 pretreatment on the susceptibility of primary cultured hepatocytes to CCl4 and cadmium chloride (CdCl2). Male and female Sprague-Dawley rats were given GdCl3 (i.v., 10 mg/kg). Twenty-four hours later, livers were either processed for preparation of microsomes or for primary cultures of hepatocytes. Gadolinium chloride treatment reduced total hepatic microsomal P450 as well as aniline hydroxylase activity by approximately 30% in males and 20% in females. In hepatocytes isolated from rats pretreated with GdCl3, the toxicity caused by CCl4, but not CdCl2 was reduced. Interestingly, when GdCl3 was administered in vitro to microsomes, there was no effect on either the microsomal P450 difference spectra or p-hydroxylation of aniline. However, when GdCl3 was incubated with isolated hepatocytes, the cytotoxicity of CCl4 (but not CdCl2) was partially attenuated. These results suggest that, in addition to its inhibitory effects on KC, GdCl3 produces other effects which may alter the susceptibility of hepatocytes to toxicity caused by certain chemicals.

  9. Dynamic Electrochemical Measurement of Chloride Ions.

    Science.gov (United States)

    Abbas, Yawar; de Graaf, Derk B; Olthuis, Wouter; van den Berg, Albert

    2016-02-05

    This protocol describes the dynamic measurement of chloride ions using the transition time of a silver silver chloride (Ag/AgCl) electrode. Silver silver chloride electrode is used extensively for potentiometric measurement of chloride ions concentration in electrolyte. In this measurement, long-term and continuous monitoring is limited due to the inherent drift and the requirement of a stable reference electrode. We utilized the chronopotentiometric approach to minimize drift and avoid the use of a conventional reference electrode. A galvanostatic pulse is applied to an Ag/AgCl electrode which initiates a faradic reaction depleting the Cl- ions near the electrode surface. The transition time, which is the time to completely deplete the ions near the electrode surface, is a function of the ion concentration, given by the Nernst equation. The square root of the transition time is in linear relation to the chloride ion concentration. Drift of the response over two weeks is negligible (59 µM/day) when measuring 1 mM [Cl-]using a current pulse of 10 Am(-2). This is a dynamic measurement where the moment of transition time determines the response and thus is independent of the absolute potential. Any metal wire can be used as a pseudo-reference electrode, making this approach feasible for long-term measurement inside concrete structures.

  10. Chloride binding site of neurotransmitter sodium symporters.

    Science.gov (United States)

    Kantcheva, Adriana K; Quick, Matthias; Shi, Lei; Winther, Anne-Marie Lund; Stolzenberg, Sebastian; Weinstein, Harel; Javitch, Jonathan A; Nissen, Poul

    2013-05-21

    Neurotransmitter:sodium symporters (NSSs) play a critical role in signaling by reuptake of neurotransmitters. Eukaryotic NSSs are chloride-dependent, whereas prokaryotic NSS homologs like LeuT are chloride-independent but contain an acidic residue (Glu290 in LeuT) at a site where eukaryotic NSSs have a serine. The LeuT-E290S mutant displays chloride-dependent activity. We show that, in LeuT-E290S cocrystallized with bromide or chloride, the anion is coordinated by side chain hydroxyls from Tyr47, Ser290, and Thr254 and the side chain amide of Gln250. The bound anion and the nearby sodium ion in the Na1 site organize a connection between their coordinating residues and the extracellular gate of LeuT through a continuous H-bond network. The specific insights from the structures, combined with results from substrate binding studies and molecular dynamics simulations, reveal an anion-dependent occlusion mechanism for NSS and shed light on the functional role of chloride binding.

  11. Chloride equilibrium potential in salamander cones

    Directory of Open Access Journals (Sweden)

    Bryson Eric J

    2004-12-01

    Full Text Available Abstract Background GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (ECl was determined in red-sensitive, large single cones from the tiger salamander retinal slice. Results Whole cell recordings were done using gramicidin perforated patch techniques to maintain endogenous Cl- levels. Membrane potentials were corrected for liquid junction potentials. Cone resting potentials were found to average -46 mV. To measure ECl, we applied long depolarizing steps to activate the calcium-activated chloride current (ICl(Ca and then determined the reversal potential for the current component that was inhibited by the Cl- channel blocker, niflumic acid. With this method, ECl was found to average -46 mV. In a complementary approach, we used a Cl-sensitive dye, MEQ, to measure the Cl- flux produced by depolarization with elevated concentrations of K+. The membrane potentials produced by the various high K+ solutions were measured in separate current clamp experiments. Consistent with electrophysiological experiments, MEQ fluorescence measurements indicated that ECl was below -36 mV. Conclusions The results of this study indicate that ECl is close to the dark resting potential. This will minimize the impact of chloride-dependent presynaptic mechanisms in cone terminals involving GABAa receptors, glutamate transporters and ICl(Ca.

  12. [Antimicrobial susceptibility in Chile 2012].

    Science.gov (United States)

    Cifuentes-D, Marcela; Silva, Francisco; García, Patricia; Bello, Helia; Briceño, Isabel; Calvo-A, Mario; Labarca, Jaime

    2014-04-01

    Bacteria antimicrobial resistance is an uncontrolled public health problem that progressively increases its magnitude and complexity. The Grupo Colaborativo de Resistencia, formed by a join of experts that represent 39 Chilean health institutions has been concerned with bacteria antimicrobial susceptibility in our country since 2008. In this document we present in vitro bacterial susceptibility accumulated during year 2012 belonging to 28 national health institutions that represent about 36% of hospital discharges in Chile. We consider of major importance to report periodically bacteria susceptibility so to keep the medical community updated to achieve target the empirical antimicrobial therapies and the control measures and prevention of the dissemination of multiresistant strains.

  13. Efficient cellulose solvent: quaternary ammonium chlorides.

    Science.gov (United States)

    Kostag, Marc; Liebert, Tim; El Seoud, Omar A; Heinze, Thomas

    2013-10-01

    Pure quaternary tetraalkylammonium chlorides with one long alkyl chain dissolved in various organic solvents constitute a new class of cellulose solvents. The electrolytes are prepared in high yields and purity by Menshutkin quaternization, an inexpensive and easy synthesis route. The pure molten tetraalkylammonium chlorides dissolve up to 15 wt% of cellulose. Cosolvents, including N,N-dimethylacetamide (DMA), may be added in large excess, leading to a system of decreased viscosity. Contrary to the well-established solvent DMA/LiCl, cellulose dissolves in DMA/quaternary ammonium chlorides without any pretreatment. Thus, the use of the new solvent avoids some disadvantages of DMA/LiCl and ionic liquids, the most extensively employed solvents for homogeneous cellulose chemistry.

  14. Alkali metal and ammonium chlorides in water and heavy water (binary systems)

    CERN Document Server

    Cohen-Adad, R

    1991-01-01

    This volume surveys the data available in the literature for solid-fluid solubility equilibria plus selected solid-liquid-vapour equilibria, for binary systems containing alkali and ammonium chlorides in water or heavy water. Solubilities covered are lithium chloride, sodium chloride, potassium chloride, rubidium chloride, caesium chloride and ammonium chloride in water and heavy water.

  15. A stepwise dechlorination/cross-coupling strategy to diversify the vancomycin 'in-chloride'.

    Science.gov (United States)

    Wadzinski, Tyler J; Gea, Katherine D; Miller, Scott J

    2016-02-01

    In an effort to rapidly access vancomycin analogues bearing diverse functionality at the 6c-Cl (the 'in-chloride') position, a two-step dechlorination/cross-coupling protocol was developed. Conditions for efficient cross-coupling of the relatively unreactive 6c-Cl group were found that ensure high conversion with minimal product decomposition. A set of 2c-dechloro-6c-functionalized vancomycin derivatives was prepared, and antibiotic activities of the compounds were evaluated against a panel of vancomycin-resistant and vancomycin-susceptible strains. Results from biological testing further underscore the steric sensitivity of vancomycin's binding pocket.

  16. Hazards of lithium thionyl chloride batteries

    Science.gov (United States)

    Parry, J. M.

    1978-01-01

    Two different topics which only relate in that they are pertinent to lithium thionyl chloride battery safety are discussed. The first topic is a hazards analysis of a system (risk assessment), a formal approach that is used in nuclear engineering, predicting oil spills, etc. It is a formalized approach for obtaining assessment of the degree of risk associated with the use of any particular system. The second topic is a small piece of chemistry related to the explosions that can occur with lithium thionyl chloride systems. After the two topics are presented, a discussion is generated among the Workshop participants.

  17. Cesium chloride-induced torsades de pointes.

    Science.gov (United States)

    Wiens, Matthew; Gordon, Wendy; Baulcomb, Daisy; Mattman, Andre; Mock, Tom; Brown, Robert

    2009-09-01

    The chloride salt of cesium, a group 1A element, is gaining popularity as an alternative treatment of advanced cancers. Cesium chloride has primarily been used in cardiovascular research for arrhythmogenesis in animals because of its potassium-blocking effects. The present report describes a 45-year-old woman with metastatic breast cancer who experienced repeated episodes of torsades de pointes polymorphic ventricular tachycardia after several months of oral cesium therapy. There was a clear temporal relationship between cesium ingestion and the arrhythmia, which later resolved following discontinuation of cesium therapy. Serial cesium plasma and whole blood levels were measured over the ensuing six months and pharmacokinetic analysis was performed.

  18. Evaluation of DUSTRAN Software System for Modeling Chloride Deposition on Steel Canisters

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Tracy T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fritz, Brad G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rutz, Frederick C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devanathan, Ram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-29

    The degradation of steel by stress corrosion cracking (SCC) when exposed to atmospheric conditions for decades is a significant challenge in the fossil fuel and nuclear industries. SCC can occur when corrosive contaminants such as chlorides are deposited on a susceptible material in a tensile stress state. The Nuclear Regulatory Commission has identified chloride-induced SCC as a potential cause for concern in stainless steel used nuclear fuel (UNF) canisters in dry storage. The modeling of contaminant deposition is the first step in predictive multiscale modeling of SCC that is essential to develop mitigation strategies, prioritize inspection, and ensure the integrity and performance of canisters, pipelines, and structural materials. A multiscale simulation approach can be developed to determine the likelihood that a canister would undergo SCC in a certain period of time. This study investigates the potential of DUSTRAN, a dust dispersion modeling system developed by Pacific Northwest National Laboratory, to model the deposition of chloride contaminants from sea salt aerosols on a steel canister. Results from DUSTRAN simulations run with historical meteorological data were compared against measured chloride data at a coastal site in Maine. DUSTRAN’s CALPUFF model tended to simulate concentrations higher than those measured; however, the closest estimations were within the same order of magnitude as the measured values. The decrease in discrepancies between measured and simulated values as the level of abstraction in wind speed decreased suggest that the model is very sensitive to wind speed. However, the influence of other parameters such as the distinction between open-ocean and surf-zone sources needs to be explored further. Deposition values predicted by the DUSTRAN system were not in agreement with concentration values and suggest that the deposition calculations may not fully represent physical processes. Overall, results indicate that with parameter

  19. Genetic diversity and disease susceptibility.

    OpenAIRE

    Bodmer, W F

    1997-01-01

    The range of genetic diversity within human populations is enormous. Genetic susceptibility to common chronic disease is a significant part of this genetic diversity, which also includes a variety of rare clear-cut inherited diseases. Modern DNA-based genomic analysis can now routinely lead to the identification of genes involved in disease susceptibility, provides the basis for genetic counselling in affected families, and more widely for a genetically targeted approach to disease prevention...

  20. Influence of chloride ion concentration on immersion corrosion behaviour of plasma sprayed alumina coatings on AZ31B magnesium alloy

    Directory of Open Access Journals (Sweden)

    D. Thirumalaikumarasamy

    2014-12-01

    Full Text Available Corrosion attack of aluminium and magnesium based alloys is a major issue worldwide. The corrosion degradation of an uncoated and atmospheric plasma sprayed alumina (APS coatings on AZ31B magnesium alloy was investigated using immersion corrosion test in NaCl solutions of different chloride ion concentrations viz., 0.01 M, 0.2 M, 0.6 M and 1 M. The corroded surface was characterized by an optical microscope and X-ray diffraction. The results showed that the corrosion deterioration of uncoated and coated samples were significantly influenced by chloride ion concentration. The uncoated magnesium and alumina coatings were found to offer a superior corrosion resistance in lower chloride ion concentration NaCl solutions (0.01 M and 0.2 M NaCl. On the other hand the coatings and Mg alloy substrate were found to be highly susceptible to localized damage, and could not provide an effective corrosion protection in solutions containing higher chloride concentrations (0.6 M and 1 M. It was found that the corrosion resistance of the ceramic coatings and base metal gets deteriorated with the increase in the chloride concentrations.

  1. 一种复方苯扎溴铵消毒剂的毒效应研究%Research on Toxic Effects of a Compound Benzalkonium Bromide Disinfectant

    Institute of Scientific and Technical Information of China (English)

    李立; 尹晓晨; 胡余明

    2012-01-01

    Objective To study the toxic effects of a compound benzalkonium bromide disinfectant and to investigate the bio- safety of the use of benzalkonium bromide as a disinfectant. Methods Acute oral toxicity, repeated skin irritation test, once damaged skin irritation test, micronucleus test and subacute toxicity test were conducted. Results The acute oral LD50 of the test substance in male and female Kunming mice was greater than 5,000 mg/kg·bw. The compound benzalkonium bromide disinfectant produced no irritation on intact skin and injured skin of rabbits. The result of the mouse bone marrow cell micronucleus test was negative. In the subacute toxicity test, after 28 d oral administration of the test .substance, the growth and development of the rats in each dose group were good. The body weight gain, indexes of the routine blood test and blood biochemical test showed no significant difference between rats in each dose group and the control group. The main organs of the experimental animals showed no obvious pathological changes. Conclusions In this experiment condition, the acute oral toxicity of the compound benzalkonium bromide disinfectant is at the actual non - toxic level. Skin irritation tests show it is a non - irritant substance. The result of the mouse bone marrow cell micronucleus test is negative. It does not produce subacute toxicity in rats. The results suggest that the normal use of the disinfectant is safe.%目的 研究一种复方苯扎溴铵消毒剂的毒性效应,了解苯扎溴铵作为消毒剂使用的生物安全性.方法 采用急性经口毒性、多次完整皮肤刺激试验、一次破损皮肤刺激试验、微核试验和亚急性毒性试验进行观察.结果 本研究中昆明种雌、雄小鼠的急性经口LD50均大于5000 mg/kg·bw;在兔多次完整皮肤刺激试验中,复方苯扎溴铵消毒剂多次接触动物完整皮肤未引起动物皮肤刺激反应;在兔一次破损皮肤刺激试验中,对白色家兔的皮肤无

  2. Antimicrobial susceptibility and susceptibility testing of Mycoplasma hominis: a review.

    Science.gov (United States)

    Bygdeman, S M; Mårdh, P A

    1983-01-01

    The determination of the minimal growth-inhibiting concentration (MIC), the minimal metabolism-inhibiting concentration (MMC), and the minimal mycoplasmacidal concentration (MCC) of various antimicrobial compounds for Mycoplasma hominis is influenced by the pH of the test media, the inoculum size, and the incubation time, although each of these factors generally do not affect the minimal concentration more than fourfold. M. hominis is resistant to beta-lactam antibiotics, vancomycin, sulfonamides, trimethoprim, and polymyxin B. There are great differences in the susceptibility of M. hominis to various macrolide antibiotics. Thus the organism is resistant to erythromycin and oleandomycin, moderately resistant to tylosin and spiramycin, susceptible to josamycin as well as to another macrolide drug, labelled M-4365G. M. hominis is also highly susceptible to the macrolide-like compound rosaramicin and to the tetracyclines (although resistant strains occur). It is susceptible to lincomycin and clindamycin, and moderately susceptible to chloramphenicol and rifampicin. The aminoglycosides have limited activity against M. hominis.

  3. Solvothermal synthesis of strontium phosphate chloride nanowire

    Science.gov (United States)

    Lam, W. M.; Wong, C. T.; Li, Z. Y.; Luk, K. D. K.; Chan, W. K.; Yang, C.; Chiu, K. Y.; Xu, B.; Lu, W. W.

    2007-08-01

    Strontium phosphate chloride nanowire was synthesized via a solvothermal treatment of strontium tri-polyphosphate and Collin salt in 1,4-dioxane at 150 °C. The effects of 1,4-dioxane concentration on particle morphology, crystallinity and phase purity were investigated in this study. The specimen morphology was analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). When the concentration of 1,4-dioxane was below 10%, micron-sized whisker was the dominant form. At 20-25% concentration of 1,4-dioxane, strontium phosphate chloride single-crystalline nanowire was 31±12 nm in diameter and 1.43±0.6 μm in length with an aspect ratio of 52.28±29.41. X-ray diffraction (XRD) pattern of this nanowire matched with that of strontium phosphate chloride (JCPDS #083-0973). When 1,4-dioxane concentration exceeded 25%, nanorod aggregate was the dominant form instead of nanowire. At 20-25% 1,4-dioxane concentration suitable strontium concentration combine with high chemical potential environment favors the formation of nanowires. By adding 1,4-dioxane impure phase such as β-strontium hydrogen phosphate, nanorod formation was suppressed. This method provides an efficient way to synthesize high aspect ratio strontium phosphate chloride nanowire. It has potential bioactive nanocomposite, high mechanical performance bioactive bone cement filler and fluorescent material applications.

  4. Controlling chloride ions diffusion in concrete.

    Science.gov (United States)

    Zeng, Lunwu; Song, Runxia

    2013-11-28

    The corrosion of steel in concrete is mainly due to the chemical reaction between the chloride ions and iron ions. Indeed, this is a serious threaten for reinforced concrete structure, especially for the reinforced concrete structure in the sea. So it is urgent and important to protect concrete against chloride ions corrosion. In this work, we report multilayer concrete can cloak chloride ions. We formulated five kinds of concrete A, B, C, D and E, which are made of different proportion of cement, sand and glue, and fabricated six-layer (ABACAD) cylinder diffusion cloak and background media E. The simulation results show that the six-layer mass diffusion cloak can protect concrete against chloride ions penetration, while the experiment results show that the concentration gradients are parallel and equal outside the outer circle in the diffusion flux lines, the iso-concentration lines are parallel outside the outer circle, and the concentration gradients in the inner circle are smaller than those outside the outer circle.

  5. Influence of compaction on chloride ingress

    NARCIS (Netherlands)

    Zlopasa, J.

    2012-01-01

    Experiences from practice show the need for more of an understanding and optimization of the compaction process in order to design a more durable concrete structure. Local variations in compaction are very often the reason for initiation of local damage and initiation of chloride induced corrosion.

  6. Liquid crystalline critical dynamics in decylammonium chloride

    CERN Document Server

    Lee, K W; Lee, C E; Kang, K H; Rhee, C; Kang, J K

    1999-01-01

    Collective chain dynamics and phase transitions in a model biomembrane, decylammonium chloride (C sub 1 sub 0 H sub 2 sub 1 NH sub 3 Cl), were studied by means of proton nuclear magnetic resonance. Our measurements sensitively reflect the critical dynamics associated with the smectic C to smectic A transition of the lipid bilayer.

  7. Chloride migration in concrete with superabsorbent polymers

    DEFF Research Database (Denmark)

    Hasholt, Marianne Tange; Jensen, Ole Mejlhede

    2015-01-01

    Superabsorbent polymers (SAP) can be used as a means for internal curing of concrete. In the present study, the development of transport properties of concrete with SAP is investigated. The chloride migration coefficient according to NT BUILD 492 is used as a measure of this. Twenty concrete mixt...

  8. Gebromeerde vlamvertragers en broomdioxines in Choline Chloride

    NARCIS (Netherlands)

    Egmond, van H.J.; Traag, W.A.; Hoogenboom, L.A.P.

    2008-01-01

    Sinds begin 2008 worden in het Nationaal Plan Diervoeder Choline Chloride monsters (= diervoeder additief) gevonden waarbij de DR CALUX screenings-assay een sterk verdacht signaal geeft, maar bij de GC-HRMS geen dioxines en dl-PCB's worden gevonden. Dit rapport beschrijft de resultaten van nader ond

  9. Amperometric Sensor for Detection of Chloride Ions

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2008-09-01

    Full Text Available Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE and at a CPE modified with solid AgNO3, a solution of AgNO3 and/or solid silver particles. Detection limits (3 S/N for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO3, solution of AgNO3 and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV we estimated the limit of detection (3 S/N as 500 nM.

  10. Regulated trafficking of the CFTR chloride channel

    NARCIS (Netherlands)

    Braakman, L.J.; Kleizen, B.; Jonge, H.R. de

    2000-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR), the ABC transporter encoded by the cystic fibrosis gene, is localized in the apical membrane of epithelial cells where it functions as a cyclic AMP-regulated chloride channel and as a regulator of other ion channels and transporters. Wh

  11. 21 CFR 582.3845 - Stannous chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Stannous chloride. 582.3845 Section 582.3845 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  12. 29 CFR 1910.1017 - Vinyl chloride.

    Science.gov (United States)

    2010-07-01

    ... possible exposure conditions. (2) Protective garments shall be provided clean and dry for each use. (i... Required Authorized Personnel Only (3) Containers of polyvinyl chloride resin waste from reactors or other... which may be useful: A. For kidney dysfunction: urine examination for albumin, red blood cells,...

  13. Spatial variability of chloride in concrete within homogeneously exposed areas

    NARCIS (Netherlands)

    Angst, U.M.; Polder, R.B.

    2014-01-01

    The concept of variability is increasingly considered in service life predictions. This paper reports experimental data on the spatial distribution of chloride in uncracked concrete subjected to homogeneous exposure. Chloride concentrations were measured with potentiometric sensors embedded in concr

  14. Viscosity and density tables of sodium chloride solutions

    Energy Technology Data Exchange (ETDEWEB)

    Fair, J.A.; Ozbek, H. (comps.)

    1977-04-01

    A file is presented containing tabulated data extracted from the scientific literature on the density and viscosity of aqueous sodium chloride solutions. Also included is a bibliography of the properties of aqueous sodium chloride solutions. (MHR)

  15. Hydrolysis of ferric chloride in solution

    Energy Technology Data Exchange (ETDEWEB)

    Lussiez, G.; Beckstead, L.

    1996-11-01

    The Detox{trademark} process uses concentrated ferric chloride and small amounts of catalysts to oxidize organic compounds. It is under consideration for oxidizing transuranic organic wastes. Although the solution is reused extensively, at some point it will reach the acceptable limit of radioactivity or maximum solubility of the radioisotopes. This solution could be cemented, but the volume would be increased substantially because of the poor compatibility of chlorides and cement. A process has been developed that recovers the chloride ions as HCl and either minimizes the volume of radioactive waste or permits recycling of the radioactive chlorides. The process involves a two-step hydrolysis at atmospheric pressure, or preferably under a slight vacuum, and relatively low temperature, about 200{degrees}C. During the first step of the process, hydrolysis occurs according to the reaction below: FeCl{sub 3 liquid} + H{sub 2}O {r_arrow} FeOCl{sub solid} + 2 HCl{sub gas} During the second step, the hot, solid, iron oxychloride is sprayed with water or placed in contact with steam, and hydrolysis proceeds to the iron oxide according to the following reaction: 2 FeOCl{sub solid} + H{sub 2}O {r_arrow} Fe{sub 2}O{sub 3 solid} + 2 HCl{sub gas}. The iron oxide, which contains radioisotopes, can then be disposed of by cementation or encapsulation. Alternately, these chlorides can be washed off of the solids and can then either be recycled or disposed of in some other way.

  16. Investigation of factors influencing chloride extraction efficiency during electrochemical chloride extraction from reinforcing concrete

    Science.gov (United States)

    Sharp, Stephen R.

    2005-11-01

    Electrochemical chloride extraction (ECE) is an accelerated bridge restoration method similar to cathodic protection, but operates at higher current densities and utilizes a temporary installation. Both techniques prolong the life of a bridge by reducing the corrosion rate of the reinforcing bar when properly applied. ECE achieves this by moving chlorides away from the reinforcement and out of the concrete while simultaneously increasing the alkalinity of the electrolyte near the reinforcing steel. Despite the proven success, significant use of ECE has not resulted in part due to an incomplete understanding in the following areas: (1) An estimation of the additional service life that can be expected following treatment when the treated member is again subjected to chlorides; (2) The cause of the decrease in current flow and, therefore, chloride removal rate during treatment; (3) Influence of water-to-cement (w/c) ratio and cover depth on the time required for treatment. This dissertation covers the research that is connected to the last two areas listed above. To begin examining these issues, plain carbon steel reinforcing bars (rebar) were embedded in portland cement concrete slabs of varying water-to-cement (w/c) ratios and cover depths, and then exposed to chlorides. A fraction of these slabs had sodium chloride added as an admixture, with all of the slabs subjected to cyclical ponding with a saturated solution of sodium chloride. ECE was then used to remove the chlorides from these slabs while making electrical measurements in the different layers between the rebar (cathode) and the titanium mat (anode) to follow the progress of the ECE process. During this study, it was revealed that the resistance of the outer concrete surface layer increases during ECE, inevitably restricting current flow, while the resistance of the underlying concrete decreases or remains constant. During ECE treatment, a white residue formed on the surface of the concrete. Analyses of the

  17. Susceptibility Genes in Thyroid Autoimmunity

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Ban

    2005-01-01

    Full Text Available The autoimmune thyroid diseases (AITD are complex diseases which are caused by an interaction between susceptibility genes and environmental triggers. Genetic susceptibility in combination with external factors (e.g. dietary iodine is believed to initiate the autoimmune response to thyroid antigens. Abundant epidemiological data, including family and twin studies, point to a strong genetic influence on the development of AITD. Various techniques have been employed to identify the genes contributing to the etiology of AITD, including candidate gene analysis and whole genome screening. These studies have enabled the identification of several loci (genetic regions that are linked with AITD, and in some of these loci, putative AITD susceptibility genes have been identified. Some of these genes/loci are unique to Graves' disease (GD and Hashimoto's thyroiditis (HT and some are common to both the diseases, indicating that there is a shared genetic susceptibility to GD and HT. The putative GD and HT susceptibility genes include both immune modifying genes (e.g. HLA, CTLA-4 and thyroid specific genes (e.g. TSHR, Tg. Most likely, these loci interact and their interactions may influence disease phenotype and severity.

  18. Stability of Alprostadil in 0.9% Sodium Chloride Stored in Polyvinyl Chloride Containers.

    Science.gov (United States)

    McCluskey, Susan V; Kirkham, Kylian; Munson, Jessica M

    2017-01-01

    The stability of alprostadil diluted in 0.9% sodium chloride stored in polyvinyl chloride (VIAFLEX) containers at refrigerated temperature, protected from light, is reported. Five solutions of alprostadil 11 mcg/mL were prepared in 250 mL 0.9% sodium chloride polyvinyl chloride (PL146) containers. The final concentration of alcohol was 2%. Samples were stored under refrigeration (2°C to 8°C) with protection from light. Two containers were submitted for potency testing and analyzed in duplicate with the stability-indicating high-performance liquid chromatography assay at specific time points over 14 days. Three containers were submitted for pH and visual testing at specific time points over 14 days. Stability was defined as retention of 90% to 110% of initial alprostadil concentration, with maintenance of the original clear, colorless, and visually particulate-free solution. Study results reported retention of 90% to 110% initial alprostadil concentration at all time points through day 10. One sample exceeded 110% potency at day 14. pH values did not change appreciably over the 14 days. There were no color changes or particle formation detected in the solutions over the study period. This study concluded that during refrigerated, light-protected storage in polyvinyl chloride (VIAFLEX) containers, a commercial alcohol-containing alprostadil formulation diluted to 11 mcg/mL with 0.9% sodium chloride 250 mL was stable for 10 days.

  19. Chemical Decontamination of Campylobacter jejuni on Chicken Skin and Meat

    DEFF Research Database (Denmark)

    Riedel, Charlotte Tandrup; Brøndsted, Lone; Rosenquist, Hanne

    2009-01-01

    .6%), and chlorhexidine diacetate salt hydrate (1%). The most effective compounds were cetylpyridinium chloride (0.5%) and benzalkonium chloride (1%) (>4.2 log). However, when these treated samples were stored for 24 h at 5°C, cetylpyridinium chloride, benzalkonium chloride, and grapefruit seed extract were less...

  20. 氯苯甲烷铵和噻吗心胺对人晶状体上皮细胞损伤作用的比较%Comparison of damage of benzalkonium chloride and timolol to human lens epithelial cell

    Institute of Scientific and Technical Information of China (English)

    项鹂; 刘谊; 张军军

    2008-01-01

    目的 了解氯苯甲烷铵和噻吗心胺对人晶状体上皮细胞(LECs)的损伤作用.方法 将不同质量浓度氯苯甲烷铵和噻吗心胺作用于人LECs,观察细胞形态变化,并用MTY还原法检测细胞活性,ELISA法检测细胞上清液中所含白介素-1α和前列腺素E2的质量浓度.结果 氯苯甲烷铵和噻吗心胺在高质量浓度时直接导致细胞死亡,前者随稀释倍数增加细胞存活率升高,但对细胞的作用转为慢性炎性刺激;后者在稀释20倍时对细胞的炎性刺激最强,随稀释倍数的增加对细胞毒害作用减轻.结论 氯苯甲烷铵作为噻吗心胺滴眼液的防腐剂,是对人LECs造成损伤并刺激其强烈分泌IL-1α和PGE2等炎性介质的主要原因.

  1. Effect of benzalkonium chloride on colonic nerve and smooth muscle of rat%苯扎氯铵对大鼠结肠神经及平滑肌的影响

    Institute of Scientific and Technical Information of China (English)

    徐纪荣; 金先庆; 陈小章

    2005-01-01

    目的研究苯扎氯铵对大鼠结肠神经及平滑肌的影响.方法 8~9周龄SD大鼠50只,随机分为两组.氯胺酮麻醉下开腹,实验组用0.1%苯扎氯铵处理大鼠降结肠浆膜40 min,温盐水冲洗后关腹,对照组用生理盐水代替苯扎氯铵.分别于术后1、2、3、4、8周取处理段结肠行组织学检查,反转录-聚合酶链反应(RT-PCR)检测乙酰胆碱酯酶(AchE)、巢蛋白(nestin)、乙酰胆碱M3受体(Chrm3)的表达,循环水浴药理学检测平滑肌收缩功能变化.结果苯扎氯铵处理后1周,大鼠结肠神经节细胞明显减少、空泡变,3周后完全消失;结肠平滑肌对乙酰胆碱敏感性增强.结论采用0.1%苯扎氯铵可使大鼠结肠产生去神经作用,结肠平滑肌对乙酰胆碱敏感性增强.

  2. Determination of Benzalkonium Chloride in Compound Tobramycin Eye Drops by HPLC%HPLC测定复方妥布霉素滴眼液中苯扎氯铵含量

    Institute of Scientific and Technical Information of China (English)

    易大为; 王静; 刘亚威; 张亚杰

    2012-01-01

      目的建立HPLC测定复方妥布霉素滴眼液中苯扎氯铵含量的方法.方法以辛烷基硅烷键合硅胶为填充剂;以0.1 mol/L乙酸钠溶液(冰乙酸调pH至5.0)-乙腈(40:60)为流动相;检测波长262 nm;流速1.0 mL/min;柱温35℃;进样量20μL.结果苯扎氯铵在0.0645~1.613μg范围内呈良好的线性关系(r=1.000);苯扎氯铵的检测限为8.5 ng,定量限为21.3 ng;苯扎氯铵平均回收率为100.8%(n=9),RSD=1.1%;空白溶液对苯扎氯铵测定无干扰.结论此法准确、可靠,可有效地控制复方妥布霉素滴眼液中苯扎氯铵的含量.

  3. Evaluation of Biofouling Inhibition Effect of Benzalkonium Chloride Imbedded Paraffin Coating%石蜡涂层包埋苯扎氯铵的抑垢效果评价

    Institute of Scientific and Technical Information of China (English)

    杨倩鹏; 常思远; 史琳

    2015-01-01

    换热器表面的微生物污垢问题,严重影响了非清洁水源换热器系统的换热效率和安全.前期研究提出的新型石蜡涂层方式,利用在线融化和凝固石蜡涂层,实现了换热器的在线清洗.石蜡涂层虽然具有一定抑垢效果,但本身也带来相应附加热阻.本研究将抑垢剂苯扎氯铵包埋至石蜡涂层,用于强化涂层的抑垢效果.污垢挂片实验结果显示,包埋苯扎氯铵的石蜡涂层抑垢效果显著增强,有效抵消了涂层附加热阻较大的缺点.相比单独使用的石蜡涂层,包埋苯扎氯铵的石蜡涂层抑垢效果增强79%.相比直接使用苯扎氯铵,包埋的苯扎氯铵作用更针对污垢底层,同样抑垢效果下苯扎氯铵用量仅为直接使用的0.6%.

  4. 硝酸毛果芸香碱滴眼液中苯扎氯铵含量测定%Determination of Benzalkonium Chloride in Pilocarpine Nitrate Eye Drops

    Institute of Scientific and Technical Information of China (English)

    黄志元; 朱样根

    2012-01-01

    目的:用高效液相色谱法(HPLC)测定硝酸毛果芸香碱滴眼液中苯扎氯铵的含量.方法:色谱柱为CN(Hypersil CN,150 mm × 4.6 mm,5 μm);流动相为0.03 mol/L磷酸二氢钠溶液(用1 mol/L氢氧化钠溶液调节pH至7.0)-乙腈(57∶43);流速为2 mL/min;检测波长为214 nm;柱温为35℃;苯扎氯铵C12、C14、C16之间的分离度应符合规定.结果:苯扎氯铵在40 ~ 160 μg/mL内线性关系良好,Y = 12.228 1 X + 6.881 4(r = 0.999 9,n = 6),回收率为99.7% ~ 101.9%,RSD = 0.66%.结论:该法操作简便,快速、准确、灵敏度高,重复性好,可用于硝酸毛果芸香碱滴眼液中苯扎氯铵的含量测定.

  5. 苯扎氯铵对人角质形成细胞炎症相关基因及通路的影响%Influence of Differently Expressed Gene and Pathway Related with Inflammatory in Human Keratinocyte Under Benzalkonium Chloride

    Institute of Scientific and Technical Information of China (English)

    苏宁; 周荷益; 杨丽; 刘娟; 郑洪艳; 张思华; 雷芳敏; 兰岚

    2016-01-01

    目的:初步探究苯扎氯铵对人角质形成细胞炎症相关基因表达水平及信号通路的影响.方法:利用MTT实验确定苯扎氯铵安全作用浓度,并暴露人角质形成细胞,通过基因芯片技术筛选差异表达的炎症相关基因,并分析其对KEGG通路的影响.结果:与对照组比较,苯扎氯铵暴露人角质形成细胞共有7个炎症相关基因发生差异性表达,涉及4条重要通路.结论:苯扎氯铵明显改变白细胞介素家族部分基因及趋化因子的表达,并通过多个信号通路调控细胞炎症反应.

  6. Effect of Borneol Combined with Benzalkonium Chloride on the Apoptosis of Rabbit Corneal Epithelial Cells%冰片与苯扎氯铵合用对兔角膜上皮细胞凋亡的作用

    Institute of Scientific and Technical Information of China (English)

    修春; 伍海涛; 王奇; 梁小雯; 廖南英; 魏秀芳; 宓穗卿; 王宁生

    2015-01-01

    目的 观察冰片与苯扎氯铵合用对兔角膜上皮细胞凋亡的作用.方法 以200 μg· mL-1冰片与不同浓度的苯扎氯铵(2,4 μg· mL-1)联合作用于兔角膜上皮细胞,用噻唑蓝(MTT)法检测上皮细胞的活性;Annexin-V/PI染色流式细胞仪法检测上皮细胞的凋亡情况;Real time RT-PCR法检测细胞凋亡相关基因Fas、Caspase3 mRNA的表达;Western Blot法检测Fas、Caspase3蛋白的表达.结果 冰片与苯扎氯铵合用可明显增强苯扎氯铵对兔角膜上皮细胞活性的抑制作用(P<0.01);增强苯扎氯铵的促凋亡作用(P<0.01);促进角膜上皮细胞Fas、caspase3的mRNA表达(P<0.01)及蛋白表达(P<0.05,P< 0.01).结论 冰片与苯扎氯铵合用,可增强苯扎氯铵的细胞毒性,促进兔角膜上皮细胞的凋亡及Fas、caspase3 mRNA和蛋白的表达.

  7. 普拉洛芬滴眼液中防腐剂苯扎氯铵的含量测定%Determination of Preservative Benzalkonium Chloride Content in Pranoprofen Eys Drops by HPLC

    Institute of Scientific and Technical Information of China (English)

    臧红波; 于海岩; 宋成君

    2011-01-01

    目的:建立普拉洛芬滴眼液中防腐剂苯扎氯铵的含量测定方法.方法:采用Diamonsfl C18色谱柱,规格为4.6×250mm,粒度为5μm,以0.02mol/L庚烷磺酸钠溶液(含0.1%三乙胺,用磷酸调节pH值3.45±0.1)-乙腈(35:65)为流动相;流速为1.5ml/min;检测波长208nm;柱温:40℃.结果:苯扎氯铵中的C12含量最高,C14和C16达不到检测限,且C12色谱峰与普拉洛芬峰及空白辅料峰均能达到有效分离.结论:选择条件显示HPLC法具有灵敏、准确、重现性好,可有效测定普拉洛芬滴眼液中防腐剂苯扎氯铵的含量.

  8. 苯扎氯铵溶液一次性用于感染腹腔冲洗的可行性研究%Benzalkonium chloride solution feasibility research on infected abdomen for disposable peritoneal irrigation

    Institute of Scientific and Technical Information of China (English)

    刘小芳; 吴云明; 李建德; 左文子; 赵志鑫; 宋金方; 吴琏; 鲁茜; 杨海滨

    2013-01-01

    目的:苯扎氯铵溶液应用于腹腔感染的一次性冲洗,观察其抗菌作用和安全性.方法:对铜绿假单胞菌、大肠埃希菌、金黄色葡萄球菌、枯草芽孢杆菌、白色念珠菌和黑曲霉菌的体外抑菌效果,以及SD大鼠和比格犬两种受试动物进行两个浓度苯扎氯铵溶液腹腔一次性冲洗后的安全性评价.体外抑菌试验采用二倍液体稀释法将0.1%原液做15个稀释级,检测其对各菌种的最小抑菌浓度.安全性研究分为对照组,模型组以及0.005%和0.01%两个浓度的给药组;给药途径为一次性腹腔冲洗;大鼠给药体积为180 mL/kg体重;比格犬给药体积为53.33 mL/kg体重;给药后观察受试动物的一般行为表现;第8天检查腹腔内各器官的大体变化,并进行血常规检查以及取肝、脾、肠和腹膜等脏器标本做病理切片检查.结果:苯扎氯铵溶液对铜绿假单胞菌、大肠埃希菌、金黄色葡萄球菌、枯草芽孢杆菌、白色念珠菌和黑曲霉菌的体外最小抑菌浓度分别为(6.25×10-3)%、(3.12×10-3)%、(9.76×10-5)%、(9.76×10-s)%、(3.91×10-4)%和(6.25×10-3)%;受试动物在手术后一周行为表现未见异常,腹腔各脏器没有明显肉眼可见毒性反应,血常规指标没有明显异常,肝、脾、肠和腹膜等脏器未见明显组织学变化.结论:苯扎氯铵溶液对铜绿假单胞菌、大肠埃希菌、金黄色葡萄球菌、枯草芽孢杆菌、白色念珠菌和黑曲霉菌均有较强的体外抑菌效果;按SD大鼠180 mL/kg和比格犬53.33 mL/kg一次性给予0.01%以下浓度(含0.01%)的苯扎氯铵溶液腹腔冲洗是安全的.说明本溶液一次性用于感染腹腔冲洗具有可行性.

  9. Effects of Benzalkonium Chloride on Human Tenon's Fibroblasts in Tissue Culture%苯扎氯铵对人Tenon囊成纤维细胞增殖的影响

    Institute of Scientific and Technical Information of China (English)

    陈宇虹; 孙兴怀

    2005-01-01

    目的观察苯扎氯铵对体外培养的人Tenon囊成纤维细胞的增殖的影响.方法体外培养人眼Tenon囊成纤维细胞.配制苯扎氯铵溶液,使其浓度依次为20、2~(2×10-7)μg/mL,采用噻唑蓝(MTT)比色法检测不同浓度的苯扎氯铵作用下细胞的增殖,并在光学显微镜下观察细胞的形态变化.结果较高浓度组(浓度≥0.2 μg/mL)的苯扎氯铵对人Tenon囊成纤维细胞存在明显的杀伤作用,20 μg/mL时细胞几乎全部死亡,A值与阴性对照相比明显减少(P<0.01),浓度为2和0.2 μg/mL时细胞形态变化明显.较低浓度组(浓度<0.2μg/mL),A值和细胞形态较阴性对照均没有明显变化(P>0.05).比较不同时间下的剂量效应曲线,4和24 h没有显著差异(P>0.05).结论苯扎氯铵0.2 μg/mL及以上浓度对体外培养的成纤维细胞具有细胞毒性,低浓度时则对细胞增殖没有明显的影响.

  10. 苯扎氯铵贴治疗47例早期嵌甲临床分析%Clinical analysis of treatment early onyxis with Benzalkonium chloride in 47 cases

    Institute of Scientific and Technical Information of China (English)

    邱卫红; 张士良

    2008-01-01

    嵌甲症是一种常见病,多为趾甲侧缘部分嵌入甲沟并反复感染引起甲沟持续性疼痛,严重困扰患者。传统的外科治疗采用拔甲术,但其复发率达70%以上。我院根据完整保留趾甲的原则,了解其解剖结构,分析病因,制定治疗方案,采用具有消炎杀菌作用的苯扎氯铵贴(也称创可贴)嵌入甲缘与甲沟之间,治疗早期嵌甲患者47例(63趾),取得了满意的疗效,现报告如下。

  11. 苯扎氯胺对体外培养的人角膜上皮细胞毒性作用的研究%Toxicity of benzalkonium chloride on human corneal epithelial cells in vitro

    Institute of Scientific and Technical Information of China (English)

    李骏; 晏晓明

    2008-01-01

    目的 观察滴眼液中最常用的防腐剂-苯扎氯胺(BAC)对体外培养的人角膜上皮细胞的毒性作用.方法 建立人角膜上皮细胞的体外培养模型.不同质量浓度的BAC(0.1%、0.01%、0.001%、0.0001%)与细胞共同孵育,时间分别为10min、30min,2、6、24、48h.评估细胞毒性的方法 :MTT分析,光镜和扫描电镜观察细胞形态学改变.结果 0.1%BAC导致细胞立即死亡,MTT值在暴露时间为10min时显著下降(P<0.01),30min降至最低(P<0.01);光镜下细胞迅速脱壁.0.01%BAC在24h内导致细胞缓慢死亡,MTT值逐渐下降;扫描电镜示细胞的形态学改变为表面微绒毛脱落,细胞膜破损;0.001%~0.0001%BAC对细胞的损害出现在24h后.结论 BAC对体外培养的人角膜上皮细胞具有明确的毒性作用,即使在滴眼液中含有的常规质量浓度(0.01%)及低于常规质量浓度下仍可出现.部分临床长期使用含有BAC滴眼液患者可出现眼表问题.

  12. Adsorption and Inhibition of Benzalkonium Chloride on Aluminum in HCl Solution%盐酸介质中苯扎氯胺在纯铝上的吸附、缓蚀作用

    Institute of Scientific and Technical Information of China (English)

    王旭珍; 焦庆祝; 郭相坤

    2001-01-01

    研究了HCl介质中苯扎氯胺(简称1227)对铝的缓蚀性能,应用吸附理论和Sekine方法对静态挂片失重实验数据进行处理.结果表明,1227对铝在HCl溶液中的腐蚀有良好的抑制作用,是一种吸附型缓蚀剂,低浓度下在铝表面上的吸附基本符合Langmuir等温式,缓蚀率随浓度和温度的增加而增大.

  13. Preventive effect of bladder irrigation with benzalkonium chloride on catheter-related inferior urethral infection%苯扎氯铵进行膀胱冲洗对导尿管相关下尿路感染的防治

    Institute of Scientific and Technical Information of China (English)

    李华; 库洪安; 皮红英

    2009-01-01

    目的:探讨使用苯扎氯铵溶液进行膀胱冲洗对长期留置尿管患者下尿路感染的防治效果.方法: 30例需要留置尿管超过3d的患者,按住院号单双号分为对照组和观察组,分别采用0.02%呋喃西林溶液和0.0025%苯扎氯铵溶液进行膀胱冲洗,在不同时间点留取中段尿标本进行尿常规及细菌学检测.结果:膀胱冲洗后第5、 9天对照组尿白细胞计数明显高于观察组,对照组尿液细菌培养的阳性率明显高于观察组(P<0.01).结论:用苯扎氯铵溶液进行膀胱冲洗,患者表现出较好的耐受性,能够有效预防和治疗与留置尿管相关的下尿路感染.

  14. Determination of azithromycin and benzalkonium chloride in Azithromycin Eye Drops by HPLC%HPLC法同时测定阿奇霉素滴眼液中阿奇霉素及苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    张琳; 刘葵葵; 王伶

    2012-01-01

    目的 建立一种高效液相色谱法同时测定阿奇霉素滴眼液中阿奇霉素及苯扎氯铵的含量.方法 采用十八烷基硅烷键合硅胶色谱柱(4.6 mm×150 mm,5μm),柱温30℃,以乙腈-磷酸盐缓冲液(取0.05 mol·L-1磷酸氢二钾溶液,用20%磷酸调节pH至8.2)(58:42)为流动相;检测波长210 nm;流速:1.0 mL· min-1.结果 阿奇霉素在1.002 8~5.0140 mg·mL-1的浓度范围内,苯扎氯铵在6.15 μg·mL-1~14.35 μg·mL-1的浓度范围内均呈线性.阿奇霉素的平均回收率100.68%,RSD 为0.50%(n=9);苯扎氯铵的平均回收率100.59%,RSD为0.92%(n=9).阿奇霉素与苯扎氯铵的定量限分别为750 ng·mL-1、46 ng·mL-1,平均含量分别为106.94%及100.04%,RSD分别为0.94%及0.67%.仪器重复性RSD值均在2.0%以下.结论 本方法简单、准确,可同时测定样品中阿奇霉素及苯扎氯铵的含量.

  15. Characterization of Antibiotic, Heavy Metal, and Benzalkonium Chloride Resistance of Plasmid-carrying Listeria monocytogenes%携带质粒李斯特菌耐药及重金属抵制特性研究

    Institute of Scientific and Technical Information of China (English)

    张辉; 包红朵; 周艳; 张莉莉; 王冉

    2015-01-01

    鉴定单核细胞增生性李斯特菌(Lm)携带质粒特性,分析携带质粒Lm对抗生素、重金属镉及苯扎氯铵的敏感性.结果表明,1 1株Lm携带内源性质粒;所有Lm菌株对阿莫西林、红霉素和利福平均敏感(22/22),对头孢拉定100%耐药(22/22);其中5株对盐酸万古霉中度耐受,部分菌株对盐酸环丙沙星(17/22)、硫酸新霉素(16/22)及盐酸四环素素(9/22)具有一定耐受性.耐镉分析表明,菌株对重金属镉呈现抵制特性(14/22),且均为携带质粒菌株;而在苯扎氯铵敏感性检测中,仅3株携带质粒Lm菌株对苯扎氯铵具有抵制性.对Lm菌株进行噬菌体杀菌检测,结果均能够被噬菌体识别并裂解.综上所述,Lm分离株耐药性增强,且对苯扎氯铵和镉有抵制特性,而噬菌体能够杀灭抵制菌株,为控制耐药及抵制性菌株污染提供了新途径.

  16. Alteration of ion transport across the colonic epithelium in the rat descending colon applying by benzalkonium chloride%苯扎氯铵对大鼠降结肠上皮离子转运的影响

    Institute of Scientific and Technical Information of China (English)

    徐纪荣; 金先庆; 陈小章

    2005-01-01

    目的探讨苯扎氯铵对大鼠降结肠上皮离子转运的影响.方法 8~9周龄SD大鼠40只,随机分为两组.氯胺酮麻醉下开腹,实验组用0.1%苯扎氯铵处理大鼠降结肠浆膜40 min,温盐水冲洗后关腹,对照组用生理盐水代替苯扎氯铵.分别于术后1,2,3,4,8周取处理段结肠,利用短路电流技术检测结肠上皮离子转运的变化.结果实验组大鼠结肠上皮各时间点跨膜电压、基础电流明显降低,钠离子吸收电流占基础电流的百分比升高.另外,由Forskolin所引起的氯离子分泌电流也明显高于对照组,但DPC阻断Forskolin所引起的短路电流的百分比下降且小于100%(对照组大于100%),而结肠跨膜电阻两组之间无差异.结论苯扎氯铵不影响大鼠结肠黏膜屏障功能, 但可造成结肠上皮离子转运功能紊乱, 提示与结肠失神经有关.

  17. 苯扎氯铵溶液外阴冲洗40例临床效果观察%Study on clinical effects of 20 cases with Benzalkonium Chloride Solution rinsing the vulva

    Institute of Scientific and Technical Information of China (English)

    李智; 李淑雯; 刘桂兰

    2010-01-01

    目的:评价苯扎氯铵溶液外阴喷洒杀菌的临床疗效及不良反应.方法:选择2010年3月在海淀区妇幼保健院分娩后的产妇40例,分为治疗组20例和对照组20例,治疗组应用0.1%苯扎氯铵溶液喷洒,对照组应用1:5 000高锰酸钾冲洗,清洁外阴后,分别于喷洒和冲洗前后取外阴拭子行细菌培养,观察细菌清除率、有效率,同时观察局部和全身反应.结果:细菌清除率治疗组为50%,对照组为20%,有效率治疗组为75%,对照组为25%,两组比较均有非常显著性差异(P<0.01);两组均未发生局部和全身不良反应.结论:苯扎氯铵溶液喷洒是安全、有效、方便、快捷的外阴杀菌剂,优于高锰酸钾冲洗.

  18. HPLC测定盐酸奥洛他定滴眼液中苯扎氯铵的含量%Determination of Benzalkonium Chloride in Olopatadine Hydrochloride Eye Drops by HPLC

    Institute of Scientific and Technical Information of China (English)

    韩文芳; 韩保萍; 朱启登; 李晓强; 邢贞琦

    2010-01-01

    目的 建立HPLC测定盐酸奥洛他定滴眼液中苯扎氯铵含量的方法.方法 以氰基键合硅胶为填充剂;乙腈-水-三乙胺为440:560:1,用磷酸调pH 3.4为流动相,流速1.0 mL/min;检测波长210 nm.结果 苯扎氯铵在0.05~0.15 mg/mL范围内呈良好的线性关系(r=0.9998);平均回收率99.7%(n=9,RSD=0.69%).结论 此方法简便灵敏准确,重复性好,可用于测定盐酸奥洛他定滴眼液中苯扎氯铵的含量.

  19. Determination of benzalkonium chloride in bromfenac sodium hydrate eye drops by HPLC%高效液相色谱法测定溴芬酸钠水合物滴眼液中苯扎氯铵的含量

    Institute of Scientific and Technical Information of China (English)

    栾爽; 韩春晖; 王磊; 钱小平

    2014-01-01

    目的:建立溴芬酸钠水合物滴眼液中防腐剂苯扎氯铵含量测定的高效液相色谱方法.方法:采用BDS HYPERSIL Cyano氰基键合硅胶色谱柱(150mm×4.6 mm,5μm),以0.1%磷酸溶液-乙腈-四氢呋喃(51∶39∶ 10)为流动相,流速1.0 mL·min-1,检测波长214 nm,柱温30℃.结果:苯扎氯铵浓度在0.9904 ~ 19.81 μg·mL-1范围内与峰面积呈良好线性关系(r=0.9999),低、中、高浓度回收率分别为99.7%、99.7%、100.2%,RSD分别为0.5%、0.5%、0.9%.结论:经过方法学验证,本法可用于溴芬酸钠水合物滴眼液中防腐剂苯扎氯铵的含量测定.

  20. The Research on the Determination Methods of the Benzalkonium Chloride%衣物消毒液中苯扎氯铵含量测定方法的研究

    Institute of Scientific and Technical Information of China (English)

    杨艳丽; 钟海娟

    2006-01-01

      衣物消毒液中的主要有效成分为苯扎氯铵,目前的测定方法主要采用中国药典化学滴定法.也有文献介绍了用于测定简单复配体系消毒液中苯扎氯铵含量的紫外分光光度法.但实验说明这些方法不适用于多组分的成分复杂的消毒液的测定,不同实验室的测定结果存在较大差异.实验分析了以上方法的反应原理及误差来源,改进了实验条件,提高了测定结果的准确度.分析说明UV-VIS分光光度法具有快速、简单、灵敏的优点,用于测定衣物消毒液中的有效成分,结果令人满意. ……

  1. 苯扎氯铵凝胶剂对生殖道感染的预防作用研究%Effectiveness of Benzalkonium Chloride (BZK) Gel on Reproductive Tract Infections

    Institute of Scientific and Technical Information of China (English)

    李卫华; 唐颖; 欧建军; 顾彪; 李洁斐; 徐晋勋; 周晓波; 丁训诚

    2006-01-01

    目的:研究苯扎氯铵(BZK)凝胶剂对妇女生殖道感染的预防作用.方法:在服务行业的从业人员中单纯随机抽取育龄健康妇女325名,按随机、双盲、对照的原则分为用药组和对照组,首先进行问卷调查,接着的3个月中用药组妇女每次性生活时使用含BZK的凝胶制剂,对照组妇女则使用不含任何药物的空白凝胶制剂.试验结束时对全体人员进行妇科常规检查和实验室检测,结果用SPSS12.0进行统计分析.结果:用药组153人,衣原体感染率为3.92%;对照组172人,淋球菌、衣原体、阴道毛滴虫、线索细胞和念珠菌的感染率分别为2.91%、2.33%、2.91%、8.72%、1.16%.用药组和对照组妇女生殖道感染差异有统计学意义.结论:BZK凝胶剂对妇女生殖道感染有一定的预防作用.

  2. Contraceptive efficacy of bioadhesive benzalkonium chloride gel in comparison with nonoxynol-9 gel%苯扎氯铵避孕凝胶剂避孕有效性的临床多中心研究

    Institute of Scientific and Technical Information of China (English)

    徐晋勋; 黄紫蓉; 吴愉; 王海云; 周晓波; 肖志琴

    2006-01-01

    目的 观察苯扎氯铵(BZK)避孕凝胶剂的避孕效果.方法 将240例健康育龄期女性志愿者随机分为两组,其中120例使用BZK避孕凝胶剂(BZK组),120例使用壬苯醇醚(NP-9)避孕胶冻剂(NP-9组),随访6个月,以寿命表法、log-rank检验比较两组的妊娠率、因症停用率和非医学原因停用率.结果两组妇女6个月时的随访率,BZK组和NP-9组分别为100.0%(120/120)和99.2%(119/120);粗累积妊娠率分别为1.72/100妇女和0.91/100妇女;粗累积因症停用率为0和2.68/100妇女;粗累积非医学原因停用率为3.39/100妇女和6.05/100妇女;两组的3种粗累积率分别比较,差异均无统计学意义(P>0.05).结论 BZK避孕凝胶剂的避孕作用与NP-9避孕胶冻剂同样有效.

  3. Clinical observation of Benzalkonium chloride solution bladder irrigation in prevention of prostate postoperative infection%苯扎氯铵溶液膀胱冲洗预防前列腺术后感染的临床观察

    Institute of Scientific and Technical Information of China (English)

    邱建宏

    2012-01-01

    目的 探讨苯扎氯铵溶液膀胱冲洗的安全性及预防感染的效果.方法 将60例前列腺增生患者随机分为治疗组与对照组,每组30例.均行经尿道前列腺电切手术,治疗组术后予0.01%苯扎氯铵溶液持续膀胱冲洗,对照组术后予0.9%氯化钠溶液持续膀胱冲洗.对照观察两组患者术后尿液常规检查.结果 治疗组治疗后细菌数、WBC、RBC明显低于对照组.结论 前列腺术后应用苯扎氯铵溶液冲洗安全性好,可有效降低尿路感染的发生率.

  4. STUDY ON HPLC METHOD TO DETERMINE THE CONTENT OF BENZALKONIUM CHLORIDE IN COMPOUND DISINFECTANT%高效液相色谱法测定复方消毒剂中苯扎氯铵含量的观察

    Institute of Scientific and Technical Information of China (English)

    刘吉起; 张向兵; 杨瑞春; 张玉勤

    2010-01-01

    目的 建立高效液相色谱法测定复方消毒剂中苯扎氯铵含量的方法.方法 用带紫外检测器的高效液相色谱仪,对经流动相稀释后的消毒液中苯扎氯铵含量进行测定观察.结果 按照选择的高效液相色谱参数对消毒液中苯扎氯铵含量进行测定,测得线性范围为100~2000 μg/ml,检出限为 17.8ng,相对标准偏差(RSD)均小于5%,回收率为92.0%~96.4%.结论 用本研究设定的高效液相色谱操作参数,测定复方消毒剂中苯扎氯铵含量,操作简便、快速、灵敏度高,有良好的稳定性和重现性.

  5. 苯扎氯铵用于椎管内穿刺皮肤消毒效果的临床观察%Clinical observation on disinfection efficacy of Benzalkonium Chloride to the spinal canal puncture skin

    Institute of Scientific and Technical Information of China (English)

    吕国义; 杨金丽; 朱王辉; 孙一凌; 杜鹃

    2012-01-01

    目的 观察苯扎氯铵用于椎管内麻醉穿刺前皮肤局部消毒的安全性和有效性.方法 35例择期行椎管内麻醉手术的住院患者,于穿刺前用0.10%苯扎氯铵溶液消毒局部皮肤,消毒范围以穿刺点为中心,周围辐射10~15 cm.消毒2遍,待自然干燥后,在距穿刺点5 cm的上、下、左、右取4个点,每个点用无菌棉签沾取标本,第一时间接种到含血琼脂平板培养基上,并立即置于37℃恒温箱孵育24 h后取出,观察菌落生长情况.结果 35例患者标本中,共采点140个,恒温孵育24 h后均未见致病菌生长;其中,1例患者的其中1个采集点有少量微球菌.苯扎氯铵溶液灭菌率达99.29%,消毒效果满意.结论 0.10%苯扎氯铵溶液用于椎管内麻醉穿刺前皮肤局部消毒,能获得满意的杀/灭菌效果,无明显皮肤刺激,效果安全、可靠.

  6. Study on the Acute Toxicity and Mutagenicity of a Kind of Benzalkonium Chloride Disinfectant%苯扎氯铵消毒液的急性毒性和致突变实验研究

    Institute of Scientific and Technical Information of China (English)

    吴争; 丁晟; 蔡宏; 肖岗; 张维民; 夏芝璐; 谌乐礼

    2010-01-01

    目的:研究以苯扎氯铵为主要有效成分消毒液的急性毒性和致突变性,为其应用安全性进行毒理学评价提供依据.方法:依据消毒技术规范(2002年版)[1]进行小鼠急性经口毒性试验、骨髓细胞微核试验、精子畸形试验.结果]:急性经口毒性试验:雄性小鼠LD50为3.16(2.71-5.01)g/kgBW、雌性小鼠LD50为3.69(2.71-5.01)g/kgBW,属低毒;小鼠骨髓嗜多染红细胞微核试验结果为阴性;小鼠精子畸形试验结果为阴性,未见有致突变性.结论:该浓度苯扎氯铵消毒液要注明使用条件.

  7. 苯扎氯铵用于骨科开放性伤口清洗消毒临床效果观察%Clinical effect observation on orthopaedic open wound cleaning and disinfection by benzalkonium chloride

    Institute of Scientific and Technical Information of China (English)

    石忠琪

    2012-01-01

    目的 观察苯扎氯铵用于骨科开放性伤口清洗消毒的有效性与安全性.方法 选取笔者所在医院60 例急症外伤患者,随机分为观察组和对照组各30 例.观察组给予0.1% 苯扎氯铵溶液冲洗伤口,冲洗顺序为0.1% 苯扎氯铵溶液、蒸馏水、双氧水、生理盐水;对照组给予常规碘伏消毒处理创面,消毒液冲洗前后,分别用无菌拭子取创口标本,进行细菌培养,观察菌落生长情况并计数冲洗前、冲洗后菌落数,比较两组消毒效果.结果 两组冲洗前测定菌落数差异无统计学意义(P > 0.05),但观察组冲洗后菌落数及减少率均明显优于对照组,差异有统计学意义(P < 0.05).结论 0.1% 苯扎氯铵溶液用于骨科开放性伤口冲洗,可明显减少伤口细菌数,具有显著的局部杀菌灭菌作用.

  8. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true 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. Retention of vinyl chloride in the human lung.

    OpenAIRE

    Krajewski, J.; Dobecki, M; Gromiec, J

    1980-01-01

    Experiments with volunteers showed that 42% of an inhaled dose of vinyl chloride is retained in the lungs. This value is independent of the concentration of vinyl chloride in the air. Elimination of vinyl chloride through the lungs is negligible since its concentration in expired air decreases immediately after the cessation of exposure.

  10. Kinetics of Vinyl Chloride Polymerization with Mixture of Initiators

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Kinetic models for the rate constants of vinyl chloride polymerization in the presence of initiator mixtures were proposed. They may be used to design the initiator recipes for the vinyl chloride polymerization with uniform rate at different temperatures at which various grades of poly(vinyl chloride) will be prepared.

  11. 46 CFR 154.1740 - Vinyl chloride: Inhibiting and inerting.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride: Inhibiting and inerting. 154.1740... Operating Requirements § 154.1740 Vinyl chloride: Inhibiting and inerting. When a vessel is carrying vinyl chloride, the master shall ensure that: (a) Section 154.1818 is met; or (b) Section 154.1710 is met,...

  12. Susceptibility to Frost-Bite

    Directory of Open Access Journals (Sweden)

    Bal Krishna

    1966-11-01

    Full Text Available The body protects its susceptible parts e.g. hands and feet from cold injury by allowing a surge of blood to flow through them on exposure to severe cold. This occurs through alternate vasodilatation and vasoconstriction known as Lewis Hunting Reaction. This phenomenon is influenced by several factors, which indirectly may also affect individual susceptibility to cold injury. The role of nutrition, adequate insulation of the body and positive heat balance in relation to the protective mechanism have been reviewed and discussed. Available literature on various factors has been surveyed and discussed in the light of recent advances in the physiology of cold exposure. Certain tests based on the present knowledge, to be developed and standardised for screening susceptible individuals to frost-bite have been suggested.

  13. Heck's disease: diagnosis and susceptibility.

    Science.gov (United States)

    Bennett, Lindsey K; Hinshaw, Molly

    2009-01-01

    Focal epithelial hyperplasia, or Heck's disease, is an uncommon proliferation of oral mucosa that presents primarily in Native Central and South American populations. It presents as asymptomatic papules or nodules on the oral mucosa, gingiva, tongue, and lips. In the majority of cases, human papilloma virus 13 or 32 is detected. Factors that determine disease susceptibility are unclear, but genetics, and having the human lymphocytic antigen-DR4 (DRB1*0404) allele in particular, are thought to play a major role in disease vulnerability. We report another case of focal epithelial hyperplasia, hypothesize on disease susceptibility, and review the current understanding of this uncommon disorder.

  14. Relation between chloride exchange diffusion and a conductive chloride pathway across the isolated skin of the toad (Bufo bufo)

    DEFF Research Database (Denmark)

    Kristensen, P; Larsen, Erik Hviid

    1978-01-01

    Substitution of chloride in the outside bathing medium of the toad skin with bromide, iodide, nitrate and sulphate leads to a reduction in the apparent exchange diffusion of chloride across this tissue, and also to a reduction of the chloride current recorded during hyperpolarization. A series of...

  15. 40 CFR 61.64 - Emission standard for polyvinyl chloride plants.

    Science.gov (United States)

    2010-07-01

    ... Standard for Vinyl Chloride § 61.64 Emission standard for polyvinyl chloride plants. An owner or operator of a polyvinyl chloride plant shall comply with the requirements of this section and § 61.65. (a... is not to exceed 0.02 g vinyl chloride/kg (0.04 lb vinyl chloride/ton) of polyvinyl chloride...

  16. Calcium/thionyl chloride battery technology

    Science.gov (United States)

    Counts, T.

    1985-12-01

    This final report documents the development efforts conducted by the Lithium Batteries Group of the Couples Department of Eagle-Picher Industries. The objective of the project was to develop calcium-thionyl chloride cell technology. The original project was divided into two main tasks. Task One was to consist of component optimization and stability studies. Once sufficiently advanced, the ongoing results of Task One were to be integrated with Task Two. Task Two was to consist of demonstration of an optimized primary cell. In July, 1983, the program was redirected. Task Two was split, with effort to be directed toward both the original primary cell and toward a high discharge rate reserve configuration cell. Additional electrolyte salts were to be evaluated as a means of improving the storability of the active calcium-thionyl chloride cell.

  17. BARRIER PROPERTIES OF VINYLIDENE CHLORIDE COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    LI Yuesheng; WENG Zhixue; HUANG Zhiming; PAN Zuren

    1996-01-01

    The permeability coefficients of a series of copolymers of vinylidene chloride (VDC)with methyl acrylate (MA), butyl acrylate (BA) or vinyl chloride (VC) (as comonomer)to oxygen and carbon dioxide have been measured at 1.0 MPa and 30℃, while those to water vapor have been measured at 30℃ and 100% relative humidity. All the copolymers are semicrystalline. VDC/MA copolymers have lower melting temperature compared with VDC/BA copolymers, while that melting temperature of VDC/VC copolymer is higher than that of VDC/acrylate copolymers with the same VDC content. The barrier property of the copolymers is predominantly controlled by crystallite, free volume fraction, and cohesive energy. The permeability coefficients of VDC/MA copolymers to oxygen, carbon dioxide, and water vapor were successfully correlated with the ratio of free volume to cohesive energy.

  18. STABILISATION OF SILTY CLAY SOIL USING CHLORIDE

    Directory of Open Access Journals (Sweden)

    TAMADHER T. ABOOD

    2007-04-01

    Full Text Available The object of this paper is to investigate the effect of adding different chloride compounds including (NaCl, MgCl2, CaCl2 on the engineering properties of silty clay soil. Various amounts of salts (2%, 4%, and 8% were added to the soil to study the effect of salts on the compaction characteristics, consistency limits and compressive strength. The main findings of this study were that the increase in the percentage of each of the chloride compounds increased the maximum dry density and decrease the optimum moisture content. The liquid limit, plastic limit and plasticity index decreased with the increase in salt content. The unconfinedcompressive strength increased as the salt content increased.

  19. Iron (III) chloride doping of CVD graphene.

    Science.gov (United States)

    Song, Yi; Fang, Wenjing; Hsu, Allen L; Kong, Jing

    2014-10-03

    Chemical doping has been shown as an effective method of reducing the sheet resistance of graphene. We present the results of our investigations into doping large area chemical vapor deposition graphene using Iron (III) Chloride (FeCl(3)). It is shown that evaporating FeCl(3) can increase the carrier concentration of monolayer graphene to greater than 10(14) cm(-2) and achieve resistances as low as 72 Ω sq(-1). We also evaluate other important properties of the doped graphene such as surface cleanliness, air stability, and solvent stability. Furthermore, we compare FeCl(3) to three other common dopants: Gold (III) Chloride (AuCl(3)), Nitric Acid (HNO(3)), and TFSA ((CF(3)SO(2))(2)NH). We show that compared to these dopants, FeCl(3) can not only achieve better sheet resistance but also has other key advantages including better solvent stability.

  20. Electrochemical Studies in Aluminum Chloride Melts

    Science.gov (United States)

    1976-07-31

    Molten Salt Systems", Symposium on Molten Salts, Symposium Volume, The Electrochemical Society , in press (1976). Manuscripts in Preparation--Related to...Fused Salt Technology, Electrochemical Society Meeting, Chicaao, May 8-13, 1973. R. A. Osteryoung, R. H. Abel, L. G. Boxall and B. H. Vassos, "An...aluminate Melts", Electrochemical Society , San Francisco, CA, May, 1974. R. A. Osteryoung, "Chemistry in Aluminum Chloride Melts", Fifth International

  1. Developing Polymer Cathode Material for the Chloride Ion Battery.

    Science.gov (United States)

    Zhao, Xiangyu; Zhao, Zhigang; Yang, Meng; Xia, Hui; Yu, Tingting; Shen, Xiaodong

    2017-01-25

    The chloride ion battery is an attractive rechargeable battery owing to its high theoretical energy density and sustainable components. An important challenge for research and development of chloride ion batteries lies in the innovation of the cathode materials. Here we report a nanostructured chloride ion-doped polymer, polypyrrole chloride, as a new type of potential cathode material for the chloride ion battery. The as-prepared polypyrrole chloride@carbon nanotubes (PPyCl@CNTs) cathode shows a high reversible capacity of 118 mAh g(-1) and superior cycling stability. Reversible electrochemical reactions of the PPyCl@CNTs cathode based on the redox reactions of nitrogen species and chloride ion transfer are demonstrated. Our work may guide and offer electrode design principles for accelerating the development of rechargeable batteries with anion transfer.

  2. The Accelerated Test of Chloride Permeability of Concrete

    Institute of Scientific and Technical Information of China (English)

    TAN Ke-feng; ODD E Gjφrv

    2003-01-01

    The availability of accelerated chloride permeability test and the effect of w/c ratio, incorporation of silica fume, maximum aggregate size and aggregate type on the chloride permeability were studied. The mathematic analysis certifies that there is a linear relationship between accelerated test and natural diffusion. Test results show that the chloride permeability of concrete increases as w/c ratio increases whilst a limited amount of replacement of cement with silica fume, the chloride permeability decreases dramatically. The maximum aggregate size in the range of 8 to 25 mm seems also affect chloride permeability but with a much less significant level. The chloride permeability of silica fume lightweight aggregate concrete is very low, especially the concrete made with dry lightweight concrete. The chloride permeability can be evaluated by this accelerated test method.

  3. Prion protein and scrapie susceptibility

    NARCIS (Netherlands)

    Smits, M.A.; Bossers, A.; Schreuder, B.E.C.

    1997-01-01

    This article presents briefly current views on the role of prion protein (PrP) in Transmissible Spongiform Encephalopathies or prion diseases and the effect of PrP polymoryhisms on the susceptibility to these diseases, with special emphasis on sheep scrapie. The PrP genotype of sheep apears to be a

  4. Topological susceptibility from overlap fermion

    Institute of Scientific and Technical Information of China (English)

    应和平; 张剑波

    2003-01-01

    We numerically calculate the topological charge of the gauge configurations on a finite lattice by the fermionic method with overlap fermions. By using the lattice index theorem, we identify the index of the massless overlap fermion operator to the topological charge of the background gauge configuration. The resulting topological susceptibility X is in good agreement with the anticipation made by Witten and Veneziano.

  5. Topological susceptibility from the overlap

    DEFF Research Database (Denmark)

    Del Debbio, Luigi; Pica, Claudio

    2003-01-01

    The chiral symmetry at finite lattice spacing of Ginsparg-Wilson fermionic actions constrains the renormalization of the lattice operators; in particular, the topological susceptibility does not require any renormalization, when using a fermionic estimator to define the topological charge. Theref...

  6. Potassium chloride production by microcline chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Orosco, Pablo, E-mail: porosco@unsl.edu.ar [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, San Luis (Argentina); Ruiz, María del Carmen [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina)

    2015-08-10

    Highlights: • Use of chlorination for the KCl production. • The reagents used were microcline, hydromagnesite and chlorine. • Isothermal and non-isothermal assays were performed in Cl{sub 2}–N{sub 2} mixture. • The chlorination generated KCl at 700 °C. • The chlorination products promote KCl formation. - Abstract: The potassium chloride is one of the most important fertilizers used in agriculture. The current demand of this salt makes interesting the study of potassium chloride production from unconventional potassium resources. In this work the potassium chloride production by chlorination of microcline was investigated. The starting reagents were microcline, hydromagnesite and chlorine. Non-isothermal and isothermal chlorination assays were carried out in a thermogravimetric device adapted to work in corrosive atmospheres. The temperature effect on potassium extraction and the phase transformations produced during chlorination of microcline were studied. The reagents and reaction products were analyzed by X-ray fluorescence (XRF) and X-ray diffraction (XRD). The experimental results indicated that by chlorination of microcline an important extraction of potassium in the temperature range from 800 to 900 °C was produced. Moreover, at 800 °C the forsterite, enstatite and magnesium aluminate spinel phases were generated.

  7. Boldine action against the stannous chloride effect.

    Science.gov (United States)

    Reiniger, I W; Ribeiro da Silva, C; Felzenszwalb, I; de Mattos, J C; de Oliveira, J F; da Silva Dantas, F J; Bezerra, R J; Caldeira-de-Araújo, A; Bernardo-Filho, M

    1999-12-15

    Peumus boldus extract has been used in popular medicine in the treatment of biliar litiase, hepatic insufficiency and liver congestion. Its effects are associated to the substance boldine that is present in its extract. In the present work, we evaluated the influence of boldine both in: (i) the structural conformation of a plasmid pUC 9.1 through gel electrophoresis analysis; and in (ii) the survival of the strain of Escherichia coli AB1157 submitted to reactive oxygen species (ROS), generated by a Fenton like reaction, induced by stannous chloride. Our results show a reduction of the lethal effect induced by stannous chloride on the survival of the E. coli culture in the presence of boldine. The supercoiled form of the plasmid is not modified by stannous chloride in the presence of boldine. We suggest that the protection induced by boldine could be explained by its anti-oxidant mechanism. In this way, the boldine could be reacting with stannous ions, protecting them against the oxidation and, consequently, avoiding the generation of ROS.

  8. Understanding microwave vessel contamination by chloride species.

    Science.gov (United States)

    Recchia, Sandro; Spanu, Davide; Bianchi, Davide; Dossi, Carlo; Pozzi, Andrea; Monticelli, Damiano

    2016-10-01

    Microwaves are widely used to assist digestion, general sample treatment and synthesis. The use of aqua regia is extensively adopted for the closed vessel mineralization of samples prior to trace element detection, leading to the contamination of microwave vessels by chlorine containing species. The latter are entrapped in the polymeric matrix of the vessels, leading to memory effects that are difficult to remove, among which the risk of silver incomplete recoveries by removal of the sparingly soluble chloride is the predominant one. In the present paper, we determined by mass spectrometry that hydrogen chloride is the species entrapped in the polymeric matrix and responsible for vessel contamination. Moreover, several decontamination treatments were considered to assess their efficiency, demonstrating that several cleaning cycles with water, nitric acid or silver nitrate in nitric acid were inefficient in removing chloride contamination (contamination reduction around 90%). Better results (≈95% decrease) were achieved by a single decontamination step in alkaline environment (sodium hydroxide or ammonia). Finally, a thermal treatment in a common laboratory oven (i.e. without vacuum and ventilation) was tested: a one hour heating at 150°C leads to a 98.5% decontamination, a figure higher than the ones obtained by wet treatments which requires comparable time. The latter treatment is a major advancement with respect to existing treatments as it avoids the need of a vacuum oven for at least 17h as presently proposed in the literature.

  9. Anti-chloride permeability and anti-chloride corrodibility of a green high performance concrete admixture in concrete

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yongbao; LIU Xinrong; LIU Dongyan; CHEN Jiangong; HUANG Xiongjun

    2003-01-01

    The effects of green high performance concrete (GHPC) admixture on the anti-chloride permeability and anti- chloride corrodibility of concrete are studied by a series of experiments designed on the basis of the diffusion principle and electrochemical principle. The GHPC admixture consists of fly ash, gangue, slag, red mud, etc., of which the mass fraction of industrial residues is over 96 %. The anti-permeabilities and anti-corrodibilities of the tested GHPC and normal concrete (NC) are evaluated by the Diffusion Coefficients of chloride which was obtained by measuring the concentration of chloride in the tested systems by the voltage difference method. It is found that the adoption of GHPC admixture greatly improves the anti-chloride permeability and anti-chloride corrodibility by modifying the inner structure and contracting the porosity of concrete to the reduce considerably the diffusion rate of chloride. The admixture is desirable regarding its engineering performances as well as economical and environmental interests.

  10. Chloride Ingress in Concrete with Different Age at Time of First Chloride Exposure

    DEFF Research Database (Denmark)

    Hansen, Esben Østergaard; Iskau, Martin Riis; Hasholt, Marianne Tange

    2016-01-01

    Concrete structures cast in spring have longer time to hydrate and are therefore denser and more resistant to chloride ingress when first subjected to deicing salts in winter than structures cast in autumn. Consequently, it is expected that a spring casting will have a longer service life....... This hypothesis is investigated in the present study by testing drilled cores from concrete cast in 2012 and 2013 on the Svendborgsund Bridge. The cores are subject to petrographic examination and mapping of chloride profiles. Moreover, chloride migration coefficients have been measured. The study shows...... that the effect of the extra time of hydration obtained when casting in spring increases the expected service life of the concrete structure significantly....

  11. Epidemic extinction in a generalized susceptible-infected-susceptible model

    Science.gov (United States)

    Chen, Hanshuang; Huang, Feng; Zhang, Haifeng; Li, Guofeng

    2017-01-01

    We study the extinction of epidemics in a generalized susceptible-infected-susceptible model, where a susceptible individual becomes infected at the rate λ when contacting m infective individual(s) simultaneously, and an infected individual spontaneously recovers at the rate μ. By employing the Wentzel-Kramers-Brillouin approximation for the master equation, the problem is reduced to finding the zero-energy trajectories in an effective Hamiltonian system, and the mean extinction time depends exponentially on the associated action S and the size of the population N, ˜ \\exp ≤ft(NS\\right) . Because of qualitatively different bifurcation features for m  =  1 and m≥slant 2 , we derive independently the expressions of S as a function of the rescaled infection rate λ /μ . For the weak infection, S scales to the distance to the bifurcation with an exponent 2 for m  =  1 and 3/2 for m≥slant 2 . Finally, a rare-event simulation method is used to validate the theory.

  12. Individual effects of sodium, potassium, calcium, and magnesium chloride salts on Lactobacillus pentosus and Saccharomyces cerevisiae growth.

    Science.gov (United States)

    Bautista-Gallego, J; Arroyo-López, F N; Durán-Quintana, M C; Garrido-Fernandez, A

    2008-07-01

    A quantitative investigation on the individual effects of sodium (NaCl), potassium (KCl), calcium (CaCl2), and magnesium (MgCl2) chloride salts against Lactobacillus pentosus and Saccharomyces cerevisiae, two representative microorganisms of table olives and other fermented vegetables, was carried out. In order to assess their potential activities, both the kinetic growth parameters and dose-response profiles in synthetic media (deMan Rogosa Sharpe broth medium and yeast-malt-peptone-glucose broth medium, respectively) were obtained and analyzed. Microbial growth was monitored via optical density measurements as a function of contact time in the presence of progressive chloride salt concentrations. Relative maximum specific growth rate and lag-phase period were modeled as a function of the chloride salt concentrations. Moreover, for each salt and microorganism tested, the noninhibitory concentrations and the MICs were estimated and compared. All chloride salts exerted a significant antimicrobial effect on the growth cycle; particularly, CaCl2 showed a similar effect to NaCl, while KCl and MgCl2 were progressively less inhibitory. Microbial susceptibility and resistance were found to be nonlinearly dose related.

  13. Biofilm susceptibility to metal toxicity.

    Science.gov (United States)

    Harrison, Joe J; Ceri, Howard; Stremick, Carol A; Turner, Raymond J

    2004-12-01

    This study compared bacterial biofilm and planktonic cell susceptibility to metal toxicity by evaluating the minimum inhibitory concentration (MIC), the planktonic minimum bactericidal concentration (MBC), and minimum biofilm eradication concentration (MBEC) using the MBEC device. In total, 17 metal cations and oxyanions, chosen to represent groups VIB to VIA of the periodic table, were each tested on biofilm and planktonic cultures of Escherichia coli JM109, Staphylococcus aureus ATCC 29213, and Pseudomonas aeruginosa ATCC 27853. In contrast to control antibiotic assays, where biofilm cultures were 2 to 64 times less susceptible to killing than logarithmically growing planktonic bacteria, metal compounds killed planktonic and biofilm cultures at the same concentration in the vast majority of combinations. Our data indicate that, under the conditions reported, growth in a biofilm does not provide resistance to bacteria against killing by metal cations or oxyanions.

  14. Topological susceptibility from the overlap

    CERN Document Server

    Del Debbio, L; Debbio, Luigi Del; Pica, Claudio

    2004-01-01

    The chiral symmetry at finite lattice spacing of Ginsparg-Wilson fermionic actions constrains the renormalization of the lattice operators; in particular, the topological susceptibility does not require any renormalization, when using a fermionic estimator to define the topological charge. Therefore, the overlap formalism appears as an appealing candidate to study the continuum limit of the topological susceptibility while keeping the systematic errors under theoretical control. We present results for the SU(3) pure gauge theory using the index of the overlap Dirac operator to study the topology of the gauge configurations. The topological charge is obtained from the zero modes of the overlap and using a new algorithm for the spectral flow analysis. A detailed comparison with cooling techniques is presented. Particular care is taken in assessing the systematic errors. Relatively high statistics (500 to 1000 independent configurations) yield an extrapolated continuum limit with errors that are comparable with ...

  15. Antimycotics susceptibility testing of dermatophytes

    Directory of Open Access Journals (Sweden)

    Arsić-Arsenijević Valentina

    2010-01-01

    Full Text Available Dermatophytes are moulds that produce infections of the skin, hair and nails of humans and animals. The most common forms among these infections are onychomycosis and tinea pedis affecting 20% of world population. These infections are usually chronic. The treatment of dermatophytoses tends to be prolonged partly because available treatments are not very effective. Antifungal drug consumption and public health expenditure are high worldwide, as well as in Serbia. For adequate therapy, it is necessary to prove infection by isolation of dermatophytes and to test the antifungal susceptibility of isolates. Susceptibility testing is important for the resistance monitoring, epidemiological research and to compare in vitro activities of new antifungal agents. The diffusion and dilution methods of susceptibility tests are used, and technical issues of importance for the proper performance and interpretation of test results are published in the document E.DEF 9.1 (EUCAST and M38-A2 (CLSI. The aim of our paper is to promptly inform the public about technical achievements in this area, as well as the new organization of laboratory for medical mycology in our country. The formation of laboratory networks coordinated by the National Reference Laboratory for the cause of mycosis need to enable interlaboratory studies and further standardization of methods for antifungal susceptibility testing of dermatophytes, reproducibility of tests and clinical correlation monitoring (MIK values and clinical outcome of dermatophytosis. The importance of the new organization is expected efficient improvement in the dermatophytosis therapy at home, better quality of patient's life and the reduction of the cost of treatment.

  16. A New Approach for Calculating Vacuum Susceptibility

    Institute of Scientific and Technical Information of China (English)

    宗红石; 平加伦; 顾建中

    2004-01-01

    Based on the Dyson-Schwinger approach, we propose a new method for calculating vacuum susceptibilities. As an example, the vector vacuum susceptibility is calculated. A comparison with the results of the previous approaches is presented.

  17. Modeling glial contributions to seizures and epileptogenesis: cation-chloride cotransporters in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Zeid M Rusan

    Full Text Available Flies carrying a kcc loss-of-function mutation are more seizure-susceptible than wild-type flies. The kcc gene is the highly conserved Drosophila melanogaster ortholog of K+/Cl- cotransporter genes thought to be expressed in all animal cell types. Here, we examined the spatial and temporal requirements for kcc loss-of-function to modify seizure-susceptibility in flies. Targeted RNA interference (RNAi of kcc in various sets of neurons was sufficient to induce severe seizure-sensitivity. Interestingly, kcc RNAi in glia was particularly effective in causing seizure-sensitivity. Knockdown of kcc in glia or neurons during development caused a reduction in seizure induction threshold, cell swelling, and brain volume increase in 24-48 hour old adult flies. Third instar larval peripheral nerves were enlarged when kcc RNAi was expressed in neurons or glia. Results suggest that a threshold of K+/Cl- cotransport dysfunction in the nervous system during development is an important determinant of seizure-susceptibility in Drosophila. The findings presented are the first attributing a causative role for glial cation-chloride cotransporters in seizures and epileptogenesis. The importance of elucidating glial cell contributions to seizure disorders and the utility of Drosophila models is discussed.

  18. Seizure-induced disinhibition of the HPA axis increases seizure susceptibility.

    Science.gov (United States)

    O'Toole, Kate K; Hooper, Andrew; Wakefield, Seth; Maguire, Jamie

    2014-01-01

    Stress is the most commonly reported precipitating factor for seizures. The proconvulsant actions of stress hormones are thought to mediate the effects of stress on seizure susceptibility. Interestingly, epileptic patients have increased basal levels of stress hormones, including corticotropin-releasing hormone (CRH) and corticosterone, which are further increased following seizures. Given the proconvulsant actions of stress hormones, we proposed that seizure-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis may contribute to future seizure susceptibility. Consistent with this hypothesis, our data demonstrate that pharmacological induction of seizures in mice with kainic acid or pilocarpine increases circulating levels of the stress hormone, corticosterone, and exogenous corticosterone administration is sufficient to increase seizure susceptibility. However, the mechanism(s) whereby seizures activate the HPA axis remain unknown. Here we demonstrate that seizure-induced activation of the HPA axis involves compromised GABAergic control of CRH neurons, which govern HPA axis function. Following seizure activity, there is a collapse of the chloride gradient due to changes in NKCC1 and KCC2 expression, resulting in reduced amplitude of sIPSPs and even depolarizing effects of GABA on CRH neurons. Seizure-induced activation of the HPA axis results in future seizure susceptibility which can be blocked by treatment with an NKCC1 inhibitor, bumetanide, or blocking the CRH signaling with Antalarmin. These data suggest that compromised GABAergic control of CRH neurons following an initial seizure event may cause hyperexcitability of the HPA axis and increase future seizure susceptibility.

  19. N-(2-Benzoylethylpropan-2-aminium chloride

    Directory of Open Access Journals (Sweden)

    Abdullah Aydın

    2012-09-01

    Full Text Available In the title salt, C12H18NO+·Cl−, N—H...Cl interactions between the free chloride anions and the organic cations connect the molecules into hydrogen-bond dimers, forming a R22(8 motif. The dimers are linked by C—H...O hydrogen bonds into chains extending along [301]. The carbonyl group is co-planar with the phenyl ring [C—C—C=O torsion angle = −3.3 (7°]. The side chain has an E conformation.

  20. Oral cadmium chloride intoxication in mice

    DEFF Research Database (Denmark)

    Andersen, O; Nielsen, J B; Svendsen, P

    1988-01-01

    Diethyldithiocarbamate (DDC) is known to alleviate acute toxicity due to injection of cadmium salts. However, when cadmium chloride was administered by the oral route, DDC enhanced rather than alleviated the acute toxicity; both oral and intraperitoneal (i.p.) administration of DDC had this effect....... Thus, orally administered DDC enhanced cadmium-induced duodenal and ileal tissue damage and inhibition of peristalsis, as indicated by an increased intestinal transit time. At low cadmium doses, the whole-body retention of cadmium was increased by oral DDC administration. Intraperitoneally administered...

  1. Synthesis of Aminolaurylpyridinium Chloride as Antimicrobial Agent

    Institute of Scientific and Technical Information of China (English)

    ZHAO Tao; SONG Xin-yuan; SUN Gang

    2008-01-01

    4-amino-laurylpyridinium chloride (ALPC) was synthesized and employed in antimicrobial finishing of wool fabrics. The structures of the salt was fully characterized by using FTIR, 1 H-NMR and 13 C-NMR analysis. The effects of pH conditions of finishing baths, finishing time and temperature, and salt concentrations were investigated. ALPC could form ionic interactions with anionic groups on wool, which contribute to durable antimicrobial functions. The finished wool fabrics exhibited antimicrobial efficacy against Escherichia coli. The washing durability of antimicrobial functions on the finished wool fabrics was also studied.

  2. Magnesium anode for chloride ion batteries.

    Science.gov (United States)

    Zhao, Xiangyu; Li, Qiang; Zhao-Karger, Zhirong; Gao, Ping; Fink, Karin; Shen, Xiaodong; Fichtner, Maximilian

    2014-07-23

    A key advantage of chloride ion battery (CIB) is its possibility to use abundant electrode materials that are different from those in Li ion batteries. Mg anode is presented as such a material for the first time and Mg/C composite prepared by ball milling of Mg and carbon black powders or thermally decomposed MgH2/C composite has been tested as anode for CIB. The electrochemical performance of FeOCl/Mg and BiOCl/Mg was investigated, demonstrating the feasibility of using Mg as anode.

  3. Chloride diffusion in partially saturated cementitious material

    DEFF Research Database (Denmark)

    Nielsen, Erik Pram; Geiker, Mette Rica

    2003-01-01

    The paper proposes a combined application of composite theory and Powers' model for microstructural development for the estimation of the diffusion coefficient as a function of the moisture content of a defect-free cementitious material. Measurements of chloride diffusion in mortar samples (440 kg....../m(3) rapid-hardening Portland cement, w/c = 0.5, maturity minimum 6 months) stored at 65% and 85% RH, as well as in vacuum-saturated mortar samples, illustrate the applicability of the method. (C) 2003 Elsevier Science Ltd. All rights reserved....

  4. Chloride regulates afferent arteriolar contraction in response to depolarization

    DEFF Research Database (Denmark)

    Hansen, P B; Jensen, B L; Skott, O

    1998-01-01

    . The results show that K+-induced contraction of smooth muscle cells in the afferent arteriole is highly sensitive to chloride, whereas neurotransmitter release and ensuing contraction is not dependent on chloride. Thus, there are different activation pathways for depolarizing vasoconstrictors......-Renal vascular reactivity is influenced by the level of dietary salt intake. Recent in vitro data suggest that afferent arteriolar contractility is modulated by extracellular chloride. In the present study, we assessed the influence of chloride on K+-induced contraction in isolated perfused rabbit...... afferent arterioles. In 70% of vessels examined, K+-induced contraction was abolished by acute substitution of bath chloride. Consecutive addition of Cl- (30, 60, 80, 100, 110, and 117 mmol/L) restored the sensitivity to K+, and half-maximal response was observed at 82 mmol/L chloride. The calcium channel...

  5. Investigation of Lithium-Thionyl Chloride Battery Safety Hazards.

    Science.gov (United States)

    1983-01-01

    LITHIUM - THIONYL CHLORIDE BATTERY SAFETY HAZARDS(U) GOULD RESEARCH CENTER ROLLING MEADOWS IL MATERIALS LAB A I ATTIA ET...838-012 7 ontract No. 60921-81-C-0363 6// Investigation of Lithium - Thionyl Chloride Battery Safety Hazards AD A 1 T 2 , Alan I. Attia Gould Research...REPORT & PERIOD COVERED Investigation of Lithium - Thionyl Chloride Final Report Battery Safety Hazards 9/28/81 - 12/31/82 6. PERFORMING ORG. REPORT

  6. Surface Chloride Concentration of Concrete under Shallow Immersion Conditions

    OpenAIRE

    Jun Liu; Kaifeng Tang; Dong Pan; Zongru Lei; Weilun Wang; Feng Xing

    2014-01-01

    Deposition of chloride ions in the surface layer of concrete is investigated in this study. In real concrete structure, chloride ions from the service environment can penetrate into concrete and deposit in the surface layer, to form the boundary condition for further diffusion towards the interior. The deposit amount of chloride ions in the surface layer is normally a function of time, rather than a constant. In the experimental investigation, concrete specimens with different mix proportions...

  7. Chloride ingress profiles measured by electron probe micro analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, O.M. [Univ. of Aberdeen (United Kingdom). Dept. of Chemistry]|[Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Structural Engineering and Materials; Coats, A.M.; Glasser, F.P. [Univ. of Aberdeen (United Kingdom). Dept. of Chemistry

    1996-11-01

    Traditional techniques for measuring chloride ingress profiles do not apply well to high performance cement paste systems; the geometric resolution of the traditional measuring techniques is too low. In this paper measurements by Electron Probe Micro Analysis (EPMA) are presented. EPMA is demonstrated to determine chloride ingress in cement paste on a micrometer scale. Potential chloride ingress routes such as cracks or the paste-aggregate interface may also be characterized by EPMA.

  8. Chloride ingress profiles measured by electron probe micro analysis

    DEFF Research Database (Denmark)

    Jensen, Ole mejlhede; Coats, Alison M.; Glasser, Fred P.

    1996-01-01

    Traditional techniques for measuring chloride ingress profiles do not apply well to high performance cement paste systems; the geometric resolution of the traditional measuring techniques is too low. In this paper measurements by Electron Probe Micro Analysis (EPMA) are presented. EPMA...... is demonstated to determine chloride ingress in cement paste on a micrometer scale. Potential chloride ingress routes such as cracks or the paste-aggregate interface may also be characterized by EPMA. Copyright (C) 1996 Elsevier Science Ltd...

  9. On barium oxide solubility in barium-containing chloride melts

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaeva, Elena V.; Zakiryanova, Irina D.; Bovet, Andrey L.; Korzun, Iraida V. [Ural Federal Univ., Yekaterinburg (Russian Federation). Inst. of High Temperature Electrochemistry

    2016-11-01

    Oxide solubility in chloride melts depends on temperature and composition of molten solvent. The solubility of barium oxide in the solvents with barium chloride content is essentially higher than that in molten alkali chlorides. Spectral data demonstrate the existence of oxychloride ionic groupings in such melts. This work presents the results of the BaO solubility in two molten BaCl{sub 2}-NaCl systems with different barium chloride content. The received data together with earlier published results revealed the main regularities of BaO solubility in molten BaO-BaCl{sub 2}-MCl systems.

  10. Stochastic modeling of reinforced concrete structures exposed to chloride attack

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Frier, Christian

    2004-01-01

    the reinforcement exceeds a critical threshold value. In the present paper a stochastic model is described by which the chloride content in a reinforced concrete structure can be estimated. The chloride ingress is modeled by a 2-dimensional diffusion process and the diffusion coefficient, surface chloride......For many reinforced concrete structures corrosion of reinforcement is an important problem since it can result in expensive maintenance and repair actions. Further, a significant reduction of the load-bearing capacity can occur. One mode of corrosion initiation is that the chloride content around...

  11. Fire's effect on chloride ingress related durability of concrete structure

    Institute of Scientific and Technical Information of China (English)

    JIN Wei-liang; ZHANG Yi

    2007-01-01

    This paper describes the effects of fire on durability of reinforced concrete structures, and points out that fire not only damages the chemical composition and physical structure of concrete by high temperature, but also leads to an additional risk due to the generation of polyvinyl chloride (PVC)combustion gases. A mathematical model is proposed to calculate chloride ingress profiles in fire damaged concrete, so as to explore the service life prediction of the structure. Rapid Chloride Migration (RCM) test was carried out to determine the chloride diffusion coefficients for the application of the mathematical model. Finally, the detected results of a reported case testified to the validity of the mathematical model.

  12. Catalytic Conversion of Cellulose to Levulinic Acid by Metal Chlorides

    Directory of Open Access Journals (Sweden)

    Beixiao Zhang

    2010-08-01

    Full Text Available The catalytic performance of various metal chlorides in the conversion of cellulose to levulinic acid in liquid water at high temperatures was investigated. The effects of reaction parameters on the yield of levulinic acid were also explored. The results showed that alkali and alkaline earth metal chlorides were not effective in conversion of cellulose, while transition metal chlorides, especially CrCl3, FeCl3 and CuCl2 and a group IIIA metal chloride (AlCl3, exhibited high catalytic activity. The catalytic performance was correlated with the acidity of the reaction system due to the addition of the metal chlorides, but more dependent on the type of metal chloride. Among those metal chlorides, chromium chloride was found to be exceptionally effective for the conversion of cellulose to levulinic acid, affording an optimum yield of 67 mol % after a reaction time of 180 min, at 200 °C, with a catalyst dosage of 0.02 M and substrate concentration of 50 wt %. Chromium metal, most of which was present in its oxide form in the solid sample and only a small part in solution as Cr3+ ion, can be easily separated from the resulting product mixture and recycled. Finally, a plausible reaction scheme for the chromium chloride catalyzed conversion of cellulose in water was proposed.

  13. Surface Chloride Concentration of Concrete under Shallow Immersion Conditions

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2014-09-01

    Full Text Available Deposition of chloride ions in the surface layer of concrete is investigated in this study. In real concrete structure, chloride ions from the service environment can penetrate into concrete and deposit in the surface layer, to form the boundary condition for further diffusion towards the interior. The deposit amount of chloride ions in the surface layer is normally a function of time, rather than a constant. In the experimental investigation, concrete specimens with different mix proportions are immersed in NaCl solution with a mass concentration of 5%, to simulate the shallow immersion condition in sea water, and the surface chloride concentrations are measured at different ages. It is found that the surface chloride concentration increases following the increasing immersion durations, and varies from a weight percentage of 0.161%–0.781% in concretes with different mix proportions. The w/c (water-to-cement ratio influences the surface chloride concentration significantly, and the higher the w/c is, the higher the surface chloride concentration will be, at the same age. However, following the prolonging of immersion duration, the difference in surface chloride concentration induced by w/c becomes smaller and smaller. The incorporation of fly ash leads to higher surface chloride concentration. The phenomena are explained based on pore structure analyses.

  14. Interpretation of postmortem vitreous concentrations of sodium and chloride.

    Science.gov (United States)

    Zilg, B; Alkass, K; Berg, S; Druid, H

    2016-06-01

    Vitreous fluid can be used to analyze sodium and chloride levels in deceased persons, but it remains unclear to what extent such results can be used to diagnose antemortem sodium or chloride imbalances. In this study we present vitreous sodium and chloride levels from more than 3000 cases. We show that vitreous sodium and chloride levels both decrease with approximately 2.2mmol/L per day after death. Since potassium is a well-established marker for postmortem interval (PMI) and easily can be analyzed along with sodium and chloride, we have correlated sodium and chloride levels with the potassium levels and present postmortem reference ranges relative the potassium levels. We found that virtually all cases outside the reference range show signs of antemortem hypo- or hypernatremia. Vitreous sodium or chloride levels can be the only means to diagnose cases of water or salt intoxication, beer potomania or dehydration. We further show that postmortem vitreous sodium and chloride strongly correlate and in practice can be used interchangeably if analysis of one of the ions fails. It has been suggested that vitreous sodium and chloride levels can be used to diagnose drowning or to distinguish saltwater from freshwater drowning. Our results show that in cases of freshwater drowning, vitreous sodium levels are decreased, but that this mainly is an effect of postmortem diffusion between the eye and surrounding water rather than due to the drowning process, since the decrease in sodium levels correlates with immersion time.

  15. Durability of cracked fibre reinforced concrete structures exposed to chlorides

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Ekman, Tom; Hansen, Kurt Kielsgaard

    1999-01-01

    is used as environmental load. The chloride penetration is characterized both qualitatively (UV-test) and quantitatively (chloride profile) and by microscopy. The test programme involves three different concrete qualities. Both steel fibres and polypropylene fibres are used in the concrete beams as well......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by exposing beams to 4-point bending until a predefined crack width is reached, using a newly developed test setup. Exposure to a concentrated chloride solution...... as main reinforcement. The effect of the cracks, the fibres and the concrete quality on the chloride penetration is studied....

  16. The DELTA 181 lithium thionyl chloride battery

    Science.gov (United States)

    Sullivan, Ralph M.; Brown, Lawrence E.; Leigh, A. P.

    In 1986, the Johns Hopkins University/Applied Physics Laboratory (JHU/APL) undertook the development of a sensor module for the DELTA 181 spacecraft, a low earth orbit (LEO) mission of less than two months duration. A large lithium thionyl chloride battery was developed as the spacecraft's primary power source, the first known such use for this technology. The exceptionally high energy density of the lithium thionyl chloride cell was the primary driver for its use, resulting in a completed battery with a specific energy density of 120 Wh/lb. Safety requirements became the primary driver shaping all aspects of the power system design and development due to concerns about the potential hazards of this relatively new, high-energy technology. However, the program was completed without incident. The spacecraft was launched on February 8, 1988, from Kennedy Space Center (KSC) with over 60,000 Wh of battery energy. It reentered on April 2, 1988, still operating after 55 days, providing a successful, practical, and visible demonstration of the use of this technology for spacecraft applications.

  17. Regulated trafficking of the CFTR chloride channel.

    Science.gov (United States)

    Kleizen, B; Braakman, I; de Jonge, H R

    2000-08-01

    The cystic fibrosis transmembrane conductance regulator (CFTR), the ABC transporter encoded by the cystic fibrosis gene, is localized in the apical membrane of epithelial cells where it functions as a cyclic AMP-regulated chloride channel and as a regulator of other ion channels and transporters. Whereas a key role of cAMP-dependent phosphorylation in CFTR-channel gating has been firmly established, more recent studies have provided clear evidence for the existence of a second level of cAMP regulation, i.e. the exocytotic recruitment of CFFR to the plasma membrane and its endocytotic retrieval. Regulated trafficking of the CFTR Cl- channel has sofar been demonstrated only in a subset of CFTR-expressing cell types. However, with the introduction of more sensitive methods to measure CFTR cycling and submembrane localization, it might turn out to be a more general phenomenon that could contribute importantly to both the regulation of CFTR-mediated chloride transport itself and to the regulation of other transporters and CFTR-modulated cellular functions. This review aims to summarize the present state of knowledge regarding polarized and regulated CFTR trafficking and endosomal recycling in epithelial cells, to discuss present gaps in our understanding of these processes at the cellular and molecular level, and to consider its possible implications for cystic fibrosis.

  18. Synthesis and structure characterization of diethyldiallylammonium chloride

    Institute of Scientific and Technical Information of China (English)

    刘立华; 龚竹青; 郑雅杰

    2003-01-01

    The unsaturated quaternary ammonium salt diethyldiallylammonium chloride(DEDAAC) was synthesized in a two-step synthetic method. The influences of the adding method of raw materials and temperature on the yields of diethylallylamine (DEAA), and drying and temperature on the synthesis of DEDAAC were investigated. The content of in-process product DEAA was determined by non-aqueous titration. The structure of product DEDAAC was identified with IR, 1 H NMR and elemental analysis. The results show that adding allyl chloride and sodium hydroxide alternately can increase the yield of DEAA and decrease by-products. In further synthesizing of DEDAAC from DEAA, the step of drying DEAA is very necessary. When DEAA is dried by solid sodium hydroxide, good columnar crystals with a high purity(mp 199.5-201.0 ℃) are obtained; when DEAA is undried or the content of water in DEAA is above 20%, only platelets with bad quality are obtained even without crystals. The suitable synthesis conditions for DEAA and DEDAAC are 35 ℃, 6 h and 40 ℃, 36 h, respectively, and their yields are 69.7% and 67.3%, respectively.

  19. Fault locator of an allyl chloride plant

    Directory of Open Access Journals (Sweden)

    Savković-Stevanović Jelenka B.

    2004-01-01

    Full Text Available Process safety analysis, which includes qualitative fault event identification, the relative frequency and event probability functions, as well as consequence analysis, was performed on an allye chloride plant. An event tree for fault diagnosis and cognitive reliability analysis, as well as a troubleshooting system, were developed. Fuzzy inductive reasoning illustrated the advantages compared to crisp inductive reasoning. A qualitative model forecast the future behavior of the system in the case of accident detection and then compared it with the actual measured data. A cognitive model including qualitative and quantitative information by fuzzy logic of the incident scenario was derived as a fault locator for an ally! chloride plant. The obtained results showed the successful application of cognitive dispersion modeling to process safety analysis. A fuzzy inductive reasoner illustrated good performance to discriminate between different types of malfunctions. This fault locator allowed risk analysis and the construction of a fault tolerant system. This study is the first report in the literature showing the cognitive reliability analysis method.

  20. THE COMPATIBILITY OF BLENDS OF POLY(VINYL CHLORIDE) OR CHLORINATED POLY(VINYL CHLORIDE) WITH POLY(METHYL METHACRYLATE)

    Institute of Scientific and Technical Information of China (English)

    WANG Qingguo; CHENG Rongshi

    1988-01-01

    IR spectral shifts of carbonyl vibrational absorption for ethyl acetate, which acts analogically as the structural unit of poly(methyl methacrylate), in cyclohexane, chloroform, chlorinated paraffins, poly(vinyl chloride) and chlorinated poly(vinyl chloride) were measured. The results suggest that there are specific interactions between the carbonyl groups and the chlorinated hydrocarbons which could be responsible for the apparent compatibility of poly(vinyl chloride) -poly(methyl methacrylate) and chlorinated poly(vinyl chloride) -poly(methyl methacrylate) blends. Additionally, the effects of the preparation mode of blend films on phase separation and observed compatibility are discussed.

  1. Mechanisms of inherited cancer susceptibility

    Institute of Scientific and Technical Information of China (English)

    Shirley HODGSON

    2008-01-01

    A small proportion of many cancers are due to inherited mutations in genes, which result in a high risk to the individual of developing specific cancers. There are several classes of genes that may be involved: tumour suppressor genes, oncogenes, genes encoding proteins involved in DNA repair and cell cycle control, and genes involved in stimulating the angiogenic pathway. Alterations in susceptibility to cancer may also be due to variations in genes involved in carcinogen metabolism. This review discusses examples of some of these genes and the associated clinical conditions caused by the inheritance of mutations in such genes.

  2. Polygenic susceptibility to testicular cancer

    DEFF Research Database (Denmark)

    Litchfield, Kevin; Mitchell, Jonathan S; Shipley, Janet

    2015-01-01

    BACKGROUND: The increasing incidence of testicular germ cell tumour (TGCT) combined with its strong heritable basis suggests that stratified screening for the early detection of TGCT may be clinically useful. We modelled the efficiency of such a personalised screening approach, based on genetic...... known TGCT susceptibility variants. The diagnostic performance of testicular biopsy and non-invasive semen analysis was also assessed, within a simulated combined screening programme. RESULTS: The area under the curve for the TGCT PRS model was 0.72 with individuals in the top 1% of the PRS having...

  3. An electrochemical investigation of the corrosion behavior of aluminum alloys in chloride containing solutions; Investigacao eletroquimica da corrosao de ligas de aluminio em solucoes contendo cloretos

    Energy Technology Data Exchange (ETDEWEB)

    Campos Filho, Jorge Eustaquio de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Quimica]. E-mail: jorgecamposfilho@yahoo.com.br; Neves, Celia de Figueiredo Cordeiro; Campos, Wagner Reis da Costa; Moreira, Marcilio Soares [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: caf@cdtn.br; wrcc@cdtn.br; msm@cdtn.br

    2005-07-01

    Aluminum alloys have been used as cladding materials for nuclear fuel in research reactors due to its corrosion resistance. Aluminum owes its good corrosion resistance to a protective barrier oxide film formed and strongly bonded to its surface. In pool type TRIGA IPR-R1 reactor, located at Centro de Desenvolvimento da Tecnologia Nuclear in Belo Horizonte, previous immersion coupon tests revealed that aluminum alloys suffer from pitting corrosion, in spite of high quality of water control. Corrosion attack is initiated by breaking the protective oxide film on aluminum alloy surface. Chloride ions can break this oxide film and stimulate metal dissolution. In this study the aluminum alloys 1050, 5052 and 6061 were used to evaluate their corrosion behavior in chloride containing solutions. The electrochemical techniques used were potentiodynamic anodic polarization and cyclic polarization. Results showed that aluminum alloys 5052 and 6061 present similar corrosion resistance in low chloride solutions (0,1 ppm NaCl) and in reactor water but both alloys are less resistant in high chloride solution (1 ppm NaCl). Aluminum alloy 1050 presented similar behavior in the three electrolytes used, regarding to pitting corrosion, indicating that the concentration of the chloride ions was not the only variable to influence its corrosion susceptibility. (author)

  4. The stress corrosion susceptibility of a quenched and tempered 12 pct crmov martensitic stainless steel

    Science.gov (United States)

    Doig, P.; Chastell, D. J.; Flewitt, P. E. J.

    1982-05-01

    The stress corrosion susceptibility of a martensitic 12 pct Cr 1 pct MoV stainless steel in alkaline chloride solution has been measured as a function of tempering heat treatment. The microstructures produced during tempering have been characterized by transmission electron microscopy and related to measured hardness values. In addition, scanning transmission electron microscopy combined with energy dispersive X-ray microanalysis has allowed the distribution of alloying elements within the microstructure to be examined. Electron energy loss spectroscopy was used to establish fully precipitate compositions, and the microanalysis results have been explained in terms of a diffusion controlled growth of grain boundary precipitates. The overall stress corrosion cracking susceptibility has been correlated with the development of chromium solute depletion profiles about prior austenite grain boundaries.

  5. ENVIRONMENTAL STABILITY OF THE POLYENE PREPARED BY DEHYDROCHLORINATION OF POLY(VINYL CHLORIDE)

    Institute of Scientific and Technical Information of China (English)

    Hong-ming Zhang; Qing-zhong Guo; Tian-lu Chen

    2003-01-01

    A high-quality polyene can be obtained by extensive dehydrochlorination of poly(vinyl chloride) (PVC) in a liquid/solid two-phase system. The liquid phase is a tetrahydrofuran solution of PVC containing a small amount of poly(ethylene glycol) with molar mass of 400 g as a phase transfer catalyst. The solid phase is potassium hydroxide particles.The structure of the polyene is polyacetylene-like and has a long conjugated C=C sequence and a narrow dispersity of polyene sequences according to its FT-infrared and Raman spectra. The environmental stability of the polyene was also studied by IR, Raman spectra and elemental analysis. Experimental results demonstrated that the polyene was susceptible to air and could be changed into a material containing high concentrations of hydroxyl and carbonyl groups. The polyene sequences were shortened and its dispersity became broader due to the effect of dioxygen.

  6. 21 CFR 177.1980 - Vinyl chloride-propylene copolymers.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... applicable to vinyl chloride-propylene copolymers used in food-packaging adhesives complying with § 175.105... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-propylene copolymers....

  7. 46 CFR 154.1745 - Vinyl chloride: Transferring operations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride: Transferring operations. 154.1745 Section 154.1745 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... Operating Requirements § 154.1745 Vinyl chloride: Transferring operations. A vessel carrying vinyl...

  8. Phosphatase inhibitors activate normal and defective CFTR chloride channels

    OpenAIRE

    Becq, F; Jensen, T J; Chang, X B; Savoia, A.; Rommens, J M; Tsui, L C; Buchwald, M; Riordan, J R; Hanrahan, J W

    1994-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is regulated by phosphorylation and dephosphorylation at multiple sites. Although activation by protein kinases has been studied in some detail, the dephosphorylation step has received little attention. This report examines the mechanisms responsible for the dephosphorylation and spontaneous deactivation ("rundown") of CFTR chloride channels excised from transfected Chinese hamster ovary (CHO) and human airway epi...

  9. Experimental and numerical investigation of chloride ingress in cracked concrete

    NARCIS (Netherlands)

    Šavija, B.

    2014-01-01

    Chloride induced corrosion of reinforcing steel is recognized as the most common deterioration mechanism affecting reinforced concrete structures. As such, it has been in focus of research for more than thirty years. Numerous studies of chloride ingress, corrosion initiation, and corrosion propagati

  10. Microwave Mapping Demonstration Using the Thermochromic Cobalt Chloride Equilibrium

    Science.gov (United States)

    Nguyen, Vu D.; Birdwhistell, Kurt R.

    2014-01-01

    An update to the thermochromic cobalt(II) chloride equilibrium demonstration is described. Filter paper that has been saturated with aqueous cobalt(II) chloride is heated for seconds in a microwave oven, producing a color change. The resulting pink and blue map is used to colorfully demonstrate Le Châtelier's principle and to illuminate the…

  11. Hydrophobic treatment of concrete as protection against chloride penetration

    NARCIS (Netherlands)

    Vries, J. de; Polder, R.B.; Borsje, H.

    1996-01-01

    Hydrophobic treatment makes a concrete surface absorb less water and less chloride. Hydrophobic treatment was studied as a protection agninst chloride penetration from deicing salts. Test methods were designed. Nine hydrophobic products were tested, of which three complied to the requirements on fin

  12. Chloride penetration into cementitious mortar at early age

    NARCIS (Netherlands)

    Caballero, J.; Polder, R.B.; Leegwater, G.A.; Fraaij, A.L.A.

    2012-01-01

    Modern service life design methods for concrete structures use chloride diffusion data as an input parameter. Abundant data exist for concrete at 28 days and, to a lesser extent, at later ages. This paper presents chloride diffusion data for mortar at ages between 1 day and 28 days age. Rapid Chlori

  13. Unsteady growth of ammonium chloride dendrites

    Science.gov (United States)

    Martyushev, L. M.; Terentiev, P. S.; Soboleva, A. S.

    2016-02-01

    Growth of ammonium chloride dendrites from aqueous solution is experimentally investigated. The growth rate υ and the radius ρ of curvature of branches are measured as a function of the relative supersaturation Δ for steady and unsteady growth conditions. It is shown that the experimental results are quantitatively described by the dependences ρ=a/Δ+b, υ=cΔ2, where the factors for primary branches are a=(1.3±0.2)·10-7 m, b=(2.5±0.4)·10-7 m, and c=(2.2±0.3)·10-4 m/s. The factor c is found to be approximately 7 times smaller for the side branches than that for the primary branches.

  14. Electrochemical properties of actinides in molten chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Lambertin, D.; Lacquement, J. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification, DRRV, 30 - Marcoule (France); Sanchez, S.; Picard, G. [Ecole Nationale Superieure de Chimie de Paris, Lab. d' Electrochimie et de Chimie Analytique, UMR 7575 du CNRS, 75 - Paris (France)

    2000-07-01

    The chemical properties of plutonium and cerium chlorides have been studied in the fused CaCl{sub 2}-NaCl equimolar mixture at 550 deg. C using a tungsten working electrode and a pO{sup 2-} indicator electrode. The standard potential of Pu(III)/Pu was determined using cyclic voltammetry. The solubility product of Pu{sub 2}O{sub 3} was calculated by potentiometric titration. The standard potential of Ce(III)/Ce have been determined by a potentiometry method. Potentiometric titrations of Ce(III) have been shown the existence of a soluble cerium oxychloride. All these data allowed us to draw the potential-pO{sup 2-} diagram which summarises the properties of plutonium and cerium compounds in the melt. (authors)

  15. [Survey of plasticizers in polyvinyl chloride toys].

    Science.gov (United States)

    Abe, Yutaka; Yamaguchi, Miku; Mutsuga, Motoh; Hirahara, Yoshichika; Kawamura, Yoko

    2012-01-01

    Plasticizers in 101 samples of polyvinyl chloride (PVC) toys on the Japanese market were surveyed. No phthalates were detected in designated toys, though bis(2-ethylhexyl)phthalate, diisononyl phthalate, diisobutyl phthalate, dibutyl phthalate, diisodecyl phthalate and benzyl butyl phthalate were detected in more than half of other toys. 2,2,4-Tributyl-1,3-pentanediol diisobutylate, o-acetyl tributyl citrate, adipates and diacetyl lauroyl glycerol, which are alternative plasticizers to phthalates, were detected. The results of structural analysis confirmed the presence of di(2-ethylhexyl)terephthalate, tributyl citrate, diisononyl 1,2-cyclohexanedicarboxylate and neopentyl glycol esters; these have not previonsly been reported in Japan. There appears to be a shift in plasticizers used for designated toys from phthalates to new plasticizers, and the number of different plasticizers is increasing.

  16. Estimating the chloride transport in cement paste

    Directory of Open Access Journals (Sweden)

    Princigallo, A.

    2012-06-01

    Full Text Available A method was developed to measure the diffusion coefficient of chloride ions in cement paste based on an analytical solution to Fick’s 2nd law in a cylindrical coordinate system. This natural method yielded diffusivity results within as little as a month. Testing time was reduced by exploiting the three-dimensional inward flux in the specimen. In an attempt to determine the saturation concentration, dense portland cement pastes were exposed to a concentrated chloride solution. The method proved to be useful for exploring cement hydration-induced changes in the diffusion coefficient of cement paste.

    Se ha desarrollado un método para medir el coeficiente de difusión de los iones cloruro en la pasta de cemento, partiendo de una aplicación analítica de la segunda ley de Fick en un sistema de coordinadas cilíndrico. Este método, que es natural, demostró ser capaz de producir resultados de difusividad en tan solo un mes. Se consiguió reducir el tiempo de ensayo mediante el aprovechamiento de la tridimensionalidad del flujo desde el exterior al interior de la probeta. A fin de determinar la concentración de saturación, se sometieron las pastas de cemento Portland a una disolución de cloruros concentrada. Este método resultó ser útil en el estudio de los cambios del coeficiente de difusión de la pasta de cemento provocados por las reacciones de hidratación que tienen lugar en esta.

  17. Behavior and products of mechano-chemical dechlorination of polyvinyl chloride and poly (vinylidene chloride).

    Science.gov (United States)

    Xiao, Xiao; Zeng, Zigao; Xiao, Songwen

    2008-02-28

    The mechano-chemical (MC) dechlorination of polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC) was performed by mechanical milling PVC/PVDC powder with zinc powder in a planetary ball mill, and the products of dechlorination were characterized by Infrared spectra (IR), X-ray diffraction (XRD), Raman spectroscopy, gas chromatography-mass spectrometry (GC-MS), and 13C solid-state nuclear magnetic resonance (NMR). The experimental results show that PVC/PVDC can be easily dechlorinated by milling with zinc powder, and formed various kinds of inorganic and organic products. Inorganic compounds included Zn2OCl(2).2H2O, Zn5(OH)8Cl2.H2O etc., and organic products involved diamond-like carbon, carbyne fragment, polyacetylene etc. Organic products formed following the paths of dechlorination, dehydrochlorination, crosslink, and oxidation. The mechano-chemical dechlorination process of PVC/PVDC may be an effective approach for carbyne synthesizing in the appropriate condition.

  18. Effects of cyclic chloride exposure on penetration of concrete cover

    Energy Technology Data Exchange (ETDEWEB)

    Hong, K.; Hooton, R.D.

    1999-09-01

    Concretes are in a state of flux between saturated and partially saturated conditions as they undergo continuous cycles of wetting and drying. In saturated concrete, dissolved ions enter through diffusion, whereas in partially saturated concrete, ion-containing fluids are absorbed by capillary suction and concentrated by evaporation of water. The primary focus of this study was to examine the effects of cyclic wetting and drying with sodium chloride solution on chloride ingress into concrete. Chloride profiles of samples exposed to various lengths and numbers of cycles were determined for three mixtures of concrete: two containing slag and/or silica fume with a 0.4 w/cm (water to cementing materials ratio) and one with a 0.3 w/cm. It was found that longer drying times increase the rate of chloride ingress. A good relationship exists between the depth of chloride penetration and the square root of the number of cycles.

  19. Preliminary Evaluation of the DUSTRAN Modeling Suite for Modeling Atmospheric Chloride Transport

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Philip; Tran, Tracy; Fritz, Bradley; Rutz, Frederick; Ross, Steven; Gorton, Alicia; Devanathan, Ram; Plante, Paul; Trainor, Kevin

    2016-05-03

    This study investigates the potential of DUSTRAN, a dust dispersion modeling system developed by Pacific Northwest National Laboratory, to model the transport of sea salt aerosols (SSA). Results from DUSTRAN simulations run with historical meteorological data were compared against privately-measured chloride data at the near coastal Maine Yankee Nuclear Power Plant (NPP) and the Environmental Protection Agency-measured CASTNET data from Acadia National Park (NP). The comparisons have provided both encouragement as to the practical value of DUSTRAN’s CALPUFF model and suggestions for further software development opportunities. All modeled concentrations were within one order of magnitude of those measured and a few test cases showed excellent agreement between modeled and measured concentrations. However, there is a lack of consistency in discrepancy which may be due to inaccurate extrapolation of meteorological data, underlying model physics, and the source term. Future research will refine the software to better capture physical phenomena. Overall, results indicate that with parameter refinement, DUSTRAN has the potential to simulate atmospheric chloride transport from known sources to inland sites for the purpose of determining the corrosion susceptibility of various structures, systems, and components at the site.

  20. DECREASING PITTING SUSCEPTIBILITY OF PASSIVE FILMS ON X70 PIPELINE STEEL IN NaCl SOLUTIONS BY ILLUMINATION

    Institute of Scientific and Technical Information of China (English)

    W.C. Zhu; W.H. Leng; J.Q. Zhang; C.N. Cao

    2006-01-01

    The influence of UV illumination on passivity and pitting susceptibility on X70 pipeline steel in a borate buffer (pH=8.4) solution containing NaCl is described. It is observed that illumination of the sample leads to a decrease in its pitting susceptibility as indicated by pitting potential and incubation time measurements in chloride containing electrolytes. This effect is strongly dependent on the applied potential during passivation. The electronic properties of the passive films on X70steel were studied by Mott-Schottky analysis and photocurrent transient measurements. The results indicated that illumination during passivation led to modifications in the electronic properties of the passive films, mainly to a decrease of the bulk doping and an increase in the surface state density. The cause for the decrease in the pitting susceptibility is preliminary explained in terms of such modifications of the passive film.

  1. Determination of the heat capacities of Lithium/BCX (bromide chloride in thionyl chloride) batteries

    Science.gov (United States)

    Kubow, Stephen A.; Takeuchi, Kenneth J.; Takeuchi, Esther S.

    1989-12-01

    Heat capacities of twelve different Lithium/BCX (BrCl in thionyl chloride) batteries in sizes AA, C, D, and DD were determined. Procedures and measurement results are reported. The procedure allowed simple, reproducible, and precise determinations of heat capacities of industrially important Lithium/BCX cells, without interfering with performance of the cells. Use of aluminum standards allowed the accuracy of the measurements to be maintained. The measured heat capacities were within 5 percent of calculated heat capacity values.

  2. PHASE EQUILIBRIUM FOR THE TERNARY SYSTEM VINYL CHLORIDE-CHLORINATED POLYETHYLENE-POLY (VINYL CHLORIDE)

    Institute of Scientific and Technical Information of China (English)

    LOU Jianfeng; WENG Zhixue; HUANG Zhiming; PAN Zuren

    1991-01-01

    Swelling capacity of vinyl chloride (VC) in chlorinated polyethylene (CPE) with 25- 40 wt% Cl at temperature 30- 57 ℃ was studied and their relationships were correlated with Langmuir and Freundlich adsorption equations. A ternary phase diagram for VC-CPE-PVC was also established.In-situ polymerization conditions of CPE-g -VC were proposed and CPE content control was analyzed for the manufacturing process of CPE-g-VC graft product based on results of phase equilibrium study.

  3. Genetically encoded optical sensors for monitoring of intracellular chloride and chloride-selective channel activity

    Directory of Open Access Journals (Sweden)

    Piotr Bregestovski

    2009-12-01

    Full Text Available This review briefly discusses the main approaches for monitoring chloride (Cl−, the most abundant physiological anion. Noninvasive monitoring of intracellular Cl− ([Cl−]i is a challenging task owing to two main difficulties: (i the low transmembrane ratio for Cl−, approximately 10:1; and (ii the small driving force for Cl−, as the Cl− reversal potential (ECl is usually close to the resting potential of the cells. Thus, for reliable monitoring of intracellular Cl−, one has to use highly sensitive probes. From several methods for intracellular Cl− analysis, genetically encoded chloride indicators represent the most promising tools. Recent achievements in the development of genetically encoded chloride probes are based on the fact that yellow fluorescent protein (YFP exhibits Cl−-sensitivity. YFP-based probes have been successfully used for quantitative analysis of Cl− transport in different cells and for high-throughput screening of modulators of Cl−-selective channels. Development of a ratiometric genetically encoded probe, Clomeleon, has provided a tool for noninvasive estimation of intracellular Cl− concentrations. While the sensitivity of this protein to Cl− is low (EC50 about 160 mM, it has been successfully used for monitoring intracellular Cl− in different cell types. Recently a CFP–YFP-based probe with a relatively high sensitivity to Cl− (EC50 about 30 mM has been developed. This construct, termed Cl-Sensor, allows ratiometric monitoring using the fluorescence excitation ratio. Of particular interest are genetically encoded probes for monitoring of ion channel distribution and activity. A new molecular probe has been constructed by introducing into the cytoplasmic domain of the Cl−-selective glycine receptor (GlyR channel the CFP–YFP-based Cl-Sensor. This construct, termed BioSensor-GlyR, has been successfully expressed in cell lines. The new genetically encoded chloride probes offer means of screening

  4. Optical, thermal and magnetic studies of pure and cobalt chloride doped L-alanine cadmium chloride

    Science.gov (United States)

    Benila, B. S.; Bright, K. C.; Delphine, S. Mary; Shabu, R.

    2017-03-01

    Single crystals of L-alanine cadmium chloride (LACC) and cobalt chloride (Co2+) doped LACC have been grown by the slow evaporation solution growth technique. The grown crystals were subjected to various characterizations such as powder XRD, SXRD, FTIR, UV-vis, EDAX, TG/DTA, VSM, Dielectric and Second Harmonic Generation (SHG) measurements. The lattice parameters of the grown crystals were determined by single crystal X-ray analysis. EDAX analysis confirms the presence of Co2+ ion in the host material. The functional group and optical behavior of the crystals were identified from FTIR and UV-vis spectrum analysis. Electrical parameters such as dielectric constant, dielectric loss have been studied. The thermal stability of the compound was found out using TGA/DTA analysis. Second Harmonic Generation of the samples was confirmed by Kurtz-Perry powder technique. Magnetic properties of the crystals studied by VSM were also reported. The encouraging results show that the cobalt chloride doped LACC crystals have greater potential applications in optical devices.

  5. Comparative effects of hydrogen chloride gas on tomato and chrysanthemum. I. Distribution and accumulation of chloride following exposure. II. Pathological anatomy of hydrogen chloride gas injury

    Energy Technology Data Exchange (ETDEWEB)

    Shriner, D.S.

    1969-01-01

    Hydrogen chloride (HCl) gas damage to plants has not been a historically important problem. However, recent practices in a number of industries, particularly glass manufacturing and pyrolysis of waste plastics, have increased the seriousness of the problem. Studies were carried out under carefully controlled exposure conditions to determine the effects of HCl gas on a relatively sensitive and a relatively resistant plant species. The macroscopic symptoms of most importance in acute damage to tomato and chrysanthemum are glazing of the lower surface, and a bifacial bronzing of interveinal and marginal areas of leaves. Microscopically, glazing was shown to be caused by a collapse of the lower epidermal cells and a partial disorganization of the spongy mesophyll of leaves. Bronzing was shown to be caused by the further collapse of the spongy mesophyll, and in some cases the palisade mesophyll and upper epidermis. Analysis of plant tissues for their free chloride content following an exposure to HCl gas was done with cell-free water extracts which were titrated on an automatic chloride titrator. On the basis of such studies, evidence suggest that the mechanism of accumulation of chlorides in plants is similar to that of fluorides, and that in subacute doses, chlorides are translocated toward the extremities of the foliar portions of the plant. In areas where a number of different types of pollution sources exist, and symptomotology is not definitive in pinpointing the source, chloride analysis of plant tissues should prove valuable as an aid to diagnosis if HCl gas was suspected.

  6. Acute lethal and teratogenic effects of tributyltin chloride and copper chloride on mahi mahi (Coryphaena hippurus) eggs and larvae.

    Science.gov (United States)

    Adema-Hannes, Rachel; Shenker, Jonathan

    2008-10-01

    Acute and chronic bioassays were used to evaluate the lethal and sublethal effects of copper chloride and tributyltin chloride on mahi mahi (Coryphaena hippurus) embryos, a pelagic life stage often found in the surface microlayer where anthropogenic contaminants can accumulate. Acute bioassay testing determined the median lethal concentration (LC50) for the test organism after 48 h of exposure. Chronic toxicity tests were used to determine the measurement of sublethal parameters, such as developmental abnormalities after 72-h exposures to the toxicants. Embryos were collected 4 h postfertilization and subsequently exposed to 1, 5, 25, 50, and 100 microg/L of copper chloride and 3, 10, 20, 30, and 50 microg/L of tributyltin chloride. Analysis of hatch rate percentage determined that the mean 48-h LC50 of copper chloride and tributyltin chloride was 32.8 and 16.7 microg/L, respectively, based on the pooled data of four experiments with four replicates for each metal. Consistent abnormalities, such as yolk sac swelling, spinal deformities, and decreased hatch rates, were observed for each metal. Teratogenic responses to copper chloride and tributyltin chloride demonstrate the need to investigate further the impacts of pollution in the open oceans to a species indigenous to, and commercially important to, the Florida (USA) coasts. This information could then lead to the future development of a surface microlayer bioassay using mahi mahi embryos.

  7. Magnetic susceptibility properties of polluted soils

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An investigation of magnetic properties using magnetic susceptibility (X) and frequency-dependent susceptibility (Xfd) was conducted on representative modern pollutants, which include smelted slag dust, automobile exhaust dust and coal ash. Their magnetic susceptibility values are more than 500×10-8 m3/kg, and frequency-dependent susceptibility values less than 3%, indicating that ample ferrimagnetic and scanty superparamagnetic grains occurred in the studied pollutants. Similar to the artificially synthetic polluted soils, the industrially-polluted soils display a negative relationship between magnetic susceptibility and frequency-dependent susceptibility. However, the unpolluted soils, e.g. the Quaternary loess in the Chinese Loess Plateau, show a positive relationship between them. In this note, we propose a convenient and effective approach for identifying the polluted soils.

  8. On quark number susceptibilities at high temperatures

    CERN Document Server

    Bazavov, A; Hegde, P; Karsch, F; Miao, C; Mukherjee, Swagato; Petreczky, P; Schmidt, C; Velytsky, A

    2013-01-01

    We calculated second and fourth order quark number susceptibilities for 2+1 flavor QCD in the high temperature region using two improved staggered fermion formulations. The calculations are performed at several lattice spacing and we show that in the continuum limit the two formulations give consistent results. We compare our continuum extrapolated results on quark number susceptibilities with recent weak coupling calculations, and find that these cannot simultaneously explain the lattice results for second and fourth order quark number susceptibilities.

  9. Chloride penetration into concrete under simulated field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Motohashi, K.; Misra, S.; Yamamoto, A. (Kajima Corp., Tokyo (Japan))

    1991-10-31

    The purpose of this study is to clarify the effect of field conditions such curing period, slump, maximum size of aggregate, etc. on chloride penetration into concrete. With a view to closely simulate the field conditions, all specimens were exposed to chloride attack for five days after casting. From the preliminary results obtained after a six month immersion in 3.3% NaCl solution, higher degrees of chloride ingress were observed in cases when the concrete was prematurely exposed to chloride attack or had a higher slump. In addition, apart from properties, such as water-cement ratio, etc., the relative orientation of the direction of penetration to that of casting, the mortar content of the mix, and the properties of the transition zone between the coarse aggregate and mortar were found to affect the diffusivity of the chloride. Under a limited number of conditions, soluble chloride content was also illustrated in addition to the total chlorides. 10 refs., 6 figs., 6 tabs.

  10. Acetogenic microbial degradation of vinyl chloride

    Science.gov (United States)

    Bradley, P.M.; Chapelle, F.H.

    2000-01-01

    Under methanogenic conditions, microbial degradation of [1,2-14C]vinyl chloride (VC) resulted in significant (14 ?? 3% maximum recovery) but transient recovery of radioactivity as 14C-acetate. Subsequently, 14C- acetate was degraded to 14CH4 and 14CO2 (18 ?? 2% and 54 ?? 3% final recoveries, respectively). In contrast, under 2-bromoethanesulfonic acid (BES) amended conditions, 14C-acetate recovery remained high (27 ?? 1% maximum recovery) throughout the study, no 14CH4 was produced, and the final recovery of 14CO2 was only 35 ?? 4%. These results demonstrate that oxidative acetogenesis may be an important mechanism for anaerobic VC biodegradation. Moreover, these results (1) demonstrate that microbial degradation of VC to CH4 and CO2 may involve oxidative acetogenesis followed by acetotrophic methanogenesis and (2) suggest that oxidative acetogenesis may be the initial step in the net oxidation of VC to CO2 reported previously under Fe(III)-reducing, SO4-reducing, and humic acids- reducing conditions.Under methanogenic conditions, microbial degradation of [1,2-14C]vinyl chloride (VC) resulted in significant (14 ?? 3% maximum recovery) but transient recovery of radioactivity as 14C-acetate. Subsequently, 14C-acetate was degraded to 14CH4 and 14CO2 (18 ?? 2% and 54 ?? 3% final recoveries respectively). In contrast, under 2-bromoethanesulfonic acid (BES) amended conditions, 14C-acetate recovery remained high (27 ?? 1% maximum recovery) throughout the study, no 14CH4 was produced, and the final recovery of 14CO2 was only 35 ?? 4%. These results demonstrate that oxidative acetogenesis may be an important mechanism for anaerobic VC biodegradation. Moreover, these results (1) demonstrate that microbial degradation of VC to CH4 and CO2 may involve oxidative acetogenesis followed by acetotrophic methanogenesis and (2) suggest that oxidative acetogenesis may be the initial step in the net oxidation of VC to CO2 reported previously under Fe(III)-reducing, SO4-reducing, and

  11. Studies on Hypokalemia Induced by Trimethyltin Chloride

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To determine the possible relationship between plasma potassium concentration and severity of acute trimethyltin chloride (TMT) poisoning and to assess the mechanism of TMT induced hypokalemia. Methods SD rats were treated with various dosages of TMT (ip). All the indices were measured and analysed for determing their possible relations with plasma K+. Results With increase of dosage, the plasma K+ level dropped rapidly, and deaths appeared more quickly. The LDs0 of TMT (ip) was 14.7 mg/kgbw. In the low dosage group (10 mg/kgbw), the plasma K+ level dropped slowly with the lowest dosage on day 6 (4.85 mmol/L). It rose again on day 11 (5.06 mmol/L), and recoverd on day 28. The poisoning signs corresponded with decline of the span of K+ level. The plasma Na+ level dropped half an hour after TMT treatment, but recovered 24 h later. In the high dosage group (46.4 mg/kgbw), the levels of plasma K+ and Na+ fell rapidly within half an hour (P<0.05), the intracellular potassium concentration of RBC did not decrerase obviously (P>0.05), the activities of Na+-K+-ATPase and Mg2+-ATPase in RBC membrane were depressed remarkably (P<0.01, P<0.05, respectively), the plasma aldosterone concentrations rose as high as tenfold (P<0.01), the arterial blood pH fell from 7.434 to 7.258 (P<0.01),pCO2 was raised from 29.62 to 45.33 mmHg (P<0.01). In the 24 h urine test, when rats were treated with TMT (21.5 mg/kgbw, ip), urine volume, urinary potassium, sodium and chloride increased significantly in comparison with those in the controls (P<0.01). Conclusion TMT could induce hypokalemia in SD rats. The available evidence suggests that TMT can induce acute renal leakage of potassium. At the same time, a significant rise of plasma aldosterone may play an important role in promoting potassium leakage from kidney to result in severe hypokalemia with inhaling acid-base abnormalities produced, which aggravate the poisoning symptoms. In the end the rats would die of respiratory

  12. Molten Triazolium Chloride Systems as New Aluminum Battery Electrolytes

    DEFF Research Database (Denmark)

    Vestergaard, B.; Bjerrum, Niels; Petrushina, Irina;

    1993-01-01

    The possibility of using molten mixtures of 1,4-dimethyl-1,2,4-triazolium chloride (DMTC) and aluminum chloride (AlCl3) as secondary battery electrolytes was studied, in some cases extended by the copresence of sodium chloride. DMTC-AlCl, mixtures demonstrated high specific conductivity in a wide...... of milliamperes per square centimeter) was observed at 0.344 V on the acidic sodium tetrachloroaluminate background, involving a free triazolium radical mechanism. Molten DMTC-AlCl3 electrolytes are acceptable for battery performance and both the aluminum anode and the triazolium electrolyte can be used as active...

  13. Calcium chloride in stabilised soil roads and runways

    Directory of Open Access Journals (Sweden)

    Harsh Vardhan

    1952-09-01

    Full Text Available Mudless, dustless, hard and all weather driving surfaces is a serious requirement of the forces.  surfacing by mixtures of definite amounts of locally available stone, gravel, sand, clay and Silt to which calculated amount of calcium chloride is added quickly compact and ultimately harden like concrete. This provides an easy, quick and economic- means of meeting the requirement.  Necessity of such surfaces, use and action of calcium chloride and resulting effects are discussed. Different methods of construction and application of calcium chloride are briefly related.

  14. Microwave evaluation of accelerated chloride ingress in mortar

    Science.gov (United States)

    Hu, C.; Case, T.; Castle, M.; Zoughi, R.; Kurtis, K.

    2001-04-01

    Corrosion of steel in reinforced concrete structures can be induced by the presence of chloride ions near the steel/concrete interface. To show the potential of microwave nondestructive testing techniques for evaluating chloride ingress, 8″×8″×8″ mortar specimens with different mixture designs were prepared. To accelerate chloride ingress, they were exposed to cyclical wet/dry conditions, where the wet condition included exposure to salt bath. A complete discussion of the results will be presented in this paper.

  15. Denitrification of fertilizer wastewater at high chloride concentration

    DEFF Research Database (Denmark)

    Ucisik, Ahmed Süheyl; Henze, Mogens

    Wastewater from fertilizer industry is characterized by high contents of chloride concentration, which normally vary between 60 and 76 g/l. Experiments with bilogical denitrification were performed in lab-scale "fill and draw" reactors with synthetic wastewater with chloride concentrations up to 77.......4 g/l. The results of the experiments showed that biological denitrification was feasible at the extreme environmental conditions prevailing in fertilizer wastewater. Stable continuous biological denitrfication of the synthetic high chloride wastewater was performed up to 77.4 g Cl/l at 37 degree C...

  16. The ionic product of water in concentrated tetramethylammonium chloride solutions.

    Science.gov (United States)

    Sipos, P; Bódi, I; May, P M; Hefter, G T

    1997-04-01

    The ionic product of water, pK(w) = - log[H(+)][OH(-)] has been determined in aqueous solutions of tetramethylammonium chloride over the concentration range of 0.1-5.5 M at 25 degrees C using high-precision glass electrode potentiometric titrations. pK(w) data relating to aqueous potassium and sodium chlorides at ionic strengths up to 5 M are markedly lower than the tetramethylammonium chloride results. These differences are almost certainly due to weak associations between potassium and (especially) sodium and hydroxide ions.

  17. Ionometric determination of chloride ion in circulating and waste waters

    Energy Technology Data Exchange (ETDEWEB)

    Bebeshko, G.I.; Afanas' eva, V.I.; Danielova, I.I.; Dmitriev, M.A.; Radchenko, A.F.

    1986-09-01

    The authors attempt to develop selective ionometric methods to determine chloride ion in waste and circulating waters from technological ore processing, containing significant amounts of sulfide ion and various flotation reagents. These waters contain practically no cations that form hard to dissolve compounds with chloride ion such as Ag/sup +/, Cu/sup +/, Hg/sup +/ or Pb/sup 2 +/. The chloride ion concentration in water varies between 10 and 100 mg/liter. Information is shown on the concentration of the main anions and flotation reagents in waters that were analyzed.

  18. Stochastic Modeling of Reinforced Concrete Structures Exposed to Chloride Attack

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Frier, Christian

    2003-01-01

    concentration and reinforcement cover depth are modeled by stochastic fields. The paper contains a description of the parameters to be included in a stochastic model and a proposal for the information needed to obtain values for the parameters in order to be ab le to perform reliability investigations...... the reinforcement exceeds a critical threshold value. In the present paper a stochastic model is described by which the chloride content in a reinforced concrete structure can be estimated. The chloride ingress is modeled by a 2-dimensional diffusion process and the diffusion coefficient, surface chloride...

  19. Chloride, bromide and iodide scintillators with europium

    Science.gov (United States)

    Zhuravleva, Mariya; Yang, Kan

    2016-09-27

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

  20. Piezoresistive Properties of Polyvinyl Chloride Composites

    Science.gov (United States)

    Toprakci, Hatice Aylin Karahan

    Textile based sensors provide an interface between the user and the electronic system by converting any type of physiological or environmental signal into electrical signals. Common applications include health monitoring, rehabilitation, multimedia, and surveillance. In this research we demonstrate fabrication of piezoresistive sensors on textile fabrics through application of a screen-printed conductive nanocomposite layer of plasticized poly(vinyl chloride) (PVC), and carbon nanofiber (CNF). In order to understand the behavior of conductive plastisol, morphological, mechanical and electrical properties of composite films were investigated for different molecular weights of PVC. Homogeneous filler dispersion and good filler/polymer interphase were observed without any dominant filler orientation. Mechanical and electrical properties were found to be affected by CNF, plasticizer content and matrix molecular weight. CNFs were found to provide substantial bridging in the matrix and enhance strength. These nanostructured composite sensors were found to be sensitive under different levels of strain which can be monitored by change in electrical resistance. Finally, we demonstrate the fabrication of piezoresistive sensors on textile fabrics through application of a screen-printed conductive nanocomposite layer of conductive plastisol. Conductive plastisol was found to show good adhesion to fabric with homogeneous CNF distribution. As in composite films, samples were found to show negative piezoresistance at different levels of strain. Strain level and filler concentration were found to affect the piezoresistive behavior and sensitivity of the printed sensors.