To see the other types of publications on this topic, follow the link: Quaternary Ammonium Compounds – metabolism.
Dissertations / Theses on the topic 'Quaternary Ammonium Compounds – metabolism'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 31 dissertations / theses for your research on the topic 'Quaternary Ammonium Compounds – metabolism.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Tezel, Ulas. "Fate and effect of quaternary ammonium compounds in biological systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28229.
Full textAbstract:
Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009.Committee Chair: Pavlostathis, Spyros G.; Committee Member: Huang, Ching-Hua; Committee Member: Hughes, Joseph B.; Committee Member: Sobecky, Patricia A.; Committee Member: Spain, Jim C.
2
McDonald, Valerie Alexandra. "Evaluating Immunotoxicity of Quaternary Ammonium Compounds." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/79723.
Full textAbstract:
Alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC) are common quaternary ammonium compounds used as disinfectants in households, medical, and restaurant settings. They cause occupational skin and respiratory hazards in humans, and developmental and reproductive toxicity in mice. They also cause increased secretions of proinflammatory cytokines in cell lines and vaginal inflammation in porcine models; but have not been evaluated for developmental immunotoxicity. We assessed immunotoxicity in-vitro with J774A.1 murine macrophage cell line by analyzing cytokine production and phagocytosis; and evaluated developmental immunotoxicity in CD-1 mice by analyzing antibody production. Additionally, because of the associations between gut microbiome dysbiosis and immune disease, we monitored changes in the microbiome as a result of ADBAC+DDAC exposure. Production of cytokines TNF-alpha and IL-6 increased at low ADBAC+DDAC concentrations, and IL-10 decreased in the murine macrophages with ADBAC+DDAC exposure. The phagocytic function of macrophages was also severely decreased. ADBAC+DDAC altered the mouse microbiome by decreasing the relative abundance of Bacteroides and increases in Clostridia in F0 and F1 generations. IgG primary and secondary responses were altered in F1 male mice; and IgA and IgM production were decreased in secondary response in F2 male mice. Since ADBAC+DDAC show signs of immunotoxicity in mice, further studies are needed to reassess risk for human exposure as ADBAC+DDAC may be contributing to immune disease.Master of Science
3
Parr, J. A. "Antimicrobial properties of silicone quaternary ammonium compounds." Thesis, Bucks New University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375600.
Full text
4
Christofides, A. "Pyrolysis gas chromatographic analysis of quaternary ammonium compounds." Thesis, Cardiff University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304009.
Full text
5
Ioannou, Christopher J. "Action of disinfectant quaternary ammonium compounds against Staphylococcus aureus." Thesis, University of Brighton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423601.
Full text
6
Owens, Gary. "Nitrate selective resins : interaction of monomeric and polymeric quaternary ammonium compounds with nitrates /." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09pho97.pdf.
Full text
7
Jennings, Megan Christina. "Bioorganic Investigation of Quaternary Ammonium Compounds: Probing Antibacterial Activity and Resistance Development with Diverse Polyamine Scaffolds." Diss., Temple University Libraries, 2017. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/434038.
Full textAbstract:
ChemistryPh.D.
Quaternary ammonium compounds (QACs) have long served as lead disinfectants in residential, industrial, and hospital settings. Their simple yet effective amphiphilic nature makes them an ideal class of compounds through which to explore antibacterial activity. We have developed novel multiQAC scaffolds through simple and cost-efficient syntheses, yielding hundreds of diverse compounds strategically designed to examine various aspects of antibacterial and anti-biofilm activity, as well as toxicity. Many of these bis-, tris-, and tetraQACs display antibacterial activity 10 to 100 times greater than conventional monoQACs, and are among the most potent biofilm eradicators to date. Through analyzing their activity against several strains, we have uncovered and provided further evidence for key tenets of amphiphilic QAC bioactivity: a balance of hydrophobic side chains with cationic head groups generates optimal antibacterial activity, though toxicity to eukaryotic cells needs to be mitigated. Given their ubiquitous nature and chemical robustness, the overuse of QACs has led to the development of QAC resistance genes that are spreading throughout the microbial world at an alarming rate. These resistant strains, when found in bacterial biofilms, are able to persist in the presence of lead commercial QAC disinfectants, warranting the development of next-generation biocides. Several of our scaffolds were designed with QAC resistance machinery in mind; thus, we utilized these compounds not only as antibacterial agents but also as chemical probes to better understand and characterize QAC-resistance in methicillin-resistant Staphylococcus aureus (MRSA). Our findings support previous postulations that triscationic QACs would retain potency against QAC-resistant strains. Furthermore, we have identified monocationic and aromatic moieties, as well as conformational rigidity, as being more prone to recognition by the resistance machinery. Using our chemical toolbox comprised of QACs of various charge state and scaffold, we explored both the mechanism and scope of QAC-resistance by examining their structure-resistance relationship. Our holistic findings have allowed us to better understand the dynamics of this system towards the design and development of next-generation QACs that will: (1) allow us to better probe the resistance machinery, and (2) remain efficacious against a variety of microbial pathogens.
Temple University--Theses
8
Hajaya, Malek Ghaleb. "Fate and effect of quaternary ammonium antimicrobial compounds on biological nitrogen removal within high-strength wastewater treatment systems." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41113.
Full textAbstract:
High strength wastewater (HSWW) generated in food processing industries is characterized by high organic carbon and nitrogen content, and thus high oxygen demand. Biological nitrogen removal (BNR) is a technology widely used for the treatment of HSWW. Food processing facilities practice sanitation to keep food contact surfaces clean and pathogen-free. Benzalkonium chlorides (BACs) are cationic quaternary ammonium antimicrobial compounds (QACs) common in industrial antimicrobial formulations. BAC-bearing wastewater generated during sanitation applications in food processing facilities is combined with other wastewater streams and typically treated in BNR systems. The poor selectivity and target specificity of the antimicrobial BACs negatively impact the performance of BNR systems due to the susceptibility of BNR microbial populations to BAC. Objectives of the research were: a) assessment and quantification of the inhibitory effect of QACs on the microbial groups, which mediate BNR in HSWW treatment systems while treating QAC-bearing HSWW; b) evaluation of the degree and extent of the contribution of QAC adsorption, inhibition, and biotransformation on the fate and effect of QACs in BNR systems. A laboratory-scale, multi-stage BNR system was continuously fed with real poultry processing wastewater amended with a mixture of three benzalkonium chlorides. The nitrogen removal efficiency initially deteriorated at a BAC feed concentration of 5 mg/L due to complete inhibition of nitrification. However, the system recovered after 27 days of operation achieving high nitrogen removal efficiency, even after the feed BAC concentration was stepwise increased up to120 mg/L. Batch assays performed using the mixed liquors of the BNR system reactors, before, during, and post BAC exposure, showed that the development of BAC biotransformation capacity and the acquisition of resistance to BAC contributed to the recovery of nitrification and nitrogen removal. Kinetic analysis based on sub-models representing BNR processes showed that BAC inhibition of denitrification and nitrification is correlated with BAC liquid-phase and solid-phase concentrations, respectively. Simulations using a comprehensive mathematical BNR model developed for this research showed that BAC degradation and the level of nitrification inhibition by BAC were dynamic brought about by acclimation and enrichment of the heterotrophic and nitrifying microbial populations, respectively. The fate and effect of BACs in the BNR system were accurately described when the interactions between adsorption, inhibition, and resistance/biotransformation were considered within the conditions prevailing in each reactor. This work is the first study on the fate and effect of antimicrobial QACs in a continuous-flow, multi-stage BNR system, and the first study to quantify and report parameter values related to BAC inhibition of nitrification and denitrification. Results of this study enable the rational design and operation of BNR systems for the efficient treatment of QAC-bearing wastewater. The outcome of this research provides information presently lacking, supporting the continuous use of QACs as antimicrobial agents in food processing facilities, when and where needed, while avoiding any negative impacts on biological treatment systems and the environment.
9
Kane, Deborah M. "Evaluation of a sanitizing system using isopropyl alcohol quaternary ammonium formula and carbon dioxide for dry-processing environments." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/14175.
Full textAbstract:
Master of ScienceFood Science
Kelly J. K. Getty
Dry-processing environments are particularly challenging to clean and sanitize because water introduced into systems not designed for wet cleaning can favor growth and establishment of pathogenic microorganisms such as Salmonella. The objective was to determine the efficacy of isopropyl alcohol quaternary ammonium (IPAQuat) formula and carbon dioxide (CO[subscript]2) sanitizer system for eliminating Enterococcus faecium and Salmonella on food contact surfaces. Coupons of stainless steel and conveyor belting material used in dry-processing environments were spot-inoculated in the center of 5 × 5 cm coupons with approximately 7.0 log CFU/ml of E. faecium and up to 10 log CFU/ml of a six-serotype composite of Salmonella and subjected to IPAQuat-CO[subscript]2 sanitation treatments using exposure times of 30 s, 1 or 5 min. After sanitation treatments, wet coupons were swabbed for post-treatment survivors. Preliminary experiments included coupons which were soiled with a flour and water solution prior to inoculation and subsequent sanitation treatments. For the main study, inoculated surfaces were soiled with a breadcrumb flour blend and allowed to sit on the lab bench for a minimum of 16 h before sanitation. Preliminary results showed that IPAQuat-CO[subscript]2 sanitizing system was effective in reducing approximately 3.0 logs of E. faecium and Salmonella from clean and soiled surfaces after 1 min exposure but higher initial inoculum levels were needed to demonstrate >5 log reductions. For the main study, pre-treatment Salmonella populations were approximately 7.0 log CFU/25 cm[superscript]2 and post-treatment survivors were 1.3, < 0.7 (detection limit), and < 0.7 log CFU/25 cm[superscript]2 after 30 s, 1 or 5 min sanitizer exposures, respectively, for both clean and soiled surfaces. Treatment with IPAQuat-CO[subscript]2 sanitation system using 30 s sanitizer exposures resulted in 5.7 log CFU/25 cm[superscript]2 reductions whereas, greater than 6.0 log CFU/25 cm[superscript]2 reductions were observed for sanitizer exposures of 1 and 5 min. The IPAQuat-CO[subscript]2 sanitation system reduced 6 logs CFU/25 cm[superscript]2 of Salmonella with sanitizer exposure times of at least 1 min. The IPAQuat-CO[subscript]2 system would, therefore, be an effective sanitation system to eliminate potential contamination from Salmonella on food contact surfaces and have application in facilities that process dry ingredients or low-moisture products.
10
John, Cathy Nisha. "Protein expression and antifungal effect of fluconazole-resistant Candida species following effective in vitro treatment with K21, a novel antifungal agent." University of Western Cape, 2019. http://hdl.handle.net/11394/7889.
Full textAbstract:
Philosophiae Doctor - PhDBackground: Oropharyngeal candidiasis, caused by the fungus Candida, is the most common opportunistic infection affecting the quality of life of immunocompromised patients. Fluconazole is widely used as the first line of treatment for fungal infections. However, the inappropriate and misguided use of the drug has led to the evolvement of fluconazole-resistant Candida organisms. This arising resistance resulted in the urgent need for the development of new antimicrobial drugs. The aim of the present study was to investigate the antifungal action of K21, a novel antimicrobial quarternary ammonium compound, on fluconazole-resistant Candida species.
11
Rowhani, Touraj. "Development and validation of an analytical method for determination of polyhexamethylene biguanide level in the presence of quaternary ammonium compounds in recreational water." Click here for download, 2006. http://wwwlib.umi.com/cr/villanova/fullcit?p1432527.
Full text
12
Potturi, Hima. "SYNTHESES AND ESTROGENICITY STUDY OF DIETHYLSTILBESTROL AND BISPHENOL-A ANALOGS AS POTENTIAL REPLACEMENT FOR BISPHENOL-A AND INVESTIGATION ON NOVEL REACTIONS INDUCED BY IODANE/QUATERNARY AMMONIUM HALIDES." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/dissertations/403.
Full textAbstract:
Dynamic isomerization of diethylstilbestrol (DES) makes it difficult to ascertain the active estrogen between its E and Z isomers. An indirect approach has been used in this project to identify the active estrogen. Methoxylated E- and Z-DES (13 and 14) and 9,10-diethylphenanthrene-3,6-diol (15), a closed ring analog of Z-DES, were synthesized and tested for their estrogenicity. The estrogenicity of 13 is higher than that of 14 and 15, which indicates that E-DES is more estrogenic than Z-DES. Dimethylstilbestrol (16), another analog of DES, was also synthesized and tested. Its estrogenicity is lower than that of DES. Non-estrogenic analogs of bisphenol-A were designed based on the observation that (15) is far less estrogenic than DES. Closed ring analogs of bisphenol-A, 3,6-dihydroxy-9,9-dimethylfluorene (34), 2,6-dihydroxy-9,9-dimethylfluorene (35), and 2,7-dhydroxy-9,9-dimethylfluorene (36) were synthesized and they were found to have little or no estrogenicity. An open ring analog of bisphenol-A, 2-(3-hydroxyphenyl)-2-(4-hydroxyphenyl)propane (33) was also synthesized and its estrogenicity is much lower than that of bisphenol-A. Polycarbonate of 36 was also synthesized and its glass transition temperature was measured using differential scanning calorimetry (DSC). Glass transition temperature of polycarbonate of 36 was found to be 199.92 oC, which is about 50o higher than that of bisphenol-A polycarbonate (150 oC). This indicates that polycarbonate of 36 forms a harder plastic than bisphenol-A polycarbonate. Compounds 2,8-dihydroxy-5,5-dioxo-dibenzothiophene (69) and 2,8-dihydroxydibenzothiophene (70) were also synthesized and were tested as non-estrogenic alternatives for bisphenol-S and bisphenol sulfide, respectively. Compound 69 and 70 were found to be less estrogenic than bisphenol-S and bisphenol sulfide respectively agreeing with our hypothesis. Iodane/quaternary ammonium halide in nitromethane was utilized to explore aromatic bromination, N-nitrosation-dealkylation, and benzoate ester formation from benzylamines. Koser's reagent was found to be a suitable iodane for aromatic bromination reaction, whereas for N-nitrosation-dealkylation, IBX gave the best yields. Further, for N-nitrosation-dealkylation reaction, the halides of quaternary ammonium salts play a crucial role. The effectiveness of halides follows F- > Cl- > Br- ~ I-. The lack of N-nitrosation-dealkylation and ester formation in the absence of nitromethane indicates that nitromethane is playing an essential role as well. Yields of benzoate ester from benzyl amines were low (~22%). Optimization experiments will be performed in the future. Plausible reaction mechanisms for these reactions were proposed. Aromatic bromination was thought to be induced either by iodane/halide adduct or by BrOH that was formed from iodane/halide adduct. Ester formation and N-nitrosation-dealkylation were believed to be induced either by alkyl nitrite or by nitrous acid, generated from the reaction of iodane/halide adduct with nitromethane.
13
Oh, Seung Dae. "Metagenomic and metatranscriptomic investigation of microorganisms exposed to benzalkonium chloride disinfectants." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52928.
Full textAbstract:
Benzalkonium chlorides (BACs) are widely used, broad-spectrum disinfectants and frequently detected in the environment, even at toxic levels for life. Since such disinfectants can induce broad resistance capabilities, BACs may fuel the emergence of antibiotic resistance in the environment. A substantial body of literature has reported that exposure to BACs causes antibiotic resistance; yet, other studies suggest that the resistance linkage is rare, unsystematic, and/or clinically insignificant. Accordingly, whether or not disinfectant exposure mediates antibiotic resistance and, if so, what molecular mechanisms underlie the resistance link remains to be clearly elucidated. Further, understanding how microbial communities degrade BACs is important not only for alleviating the possible occurrence of antibiotic resistance but also reducing the potential risks to environmental and public health.
An integrated strategy that combines metagenomics, metatranscriptomics, genetics, and traditional culture-dependent approaches was employed to provide novel insights into these issues. The integrative approach showed that a microbial community exposed to BACs can acquire antibiotic resistance through two mechanisms: i) horizontal transfer of previously uncharacterized efflux pump genes conferring resistance to BACs and antibiotics, which were encoded on a conjugative plasmid and co-selected together upon BACs and ii) selective enrichment of intrinsically multi-drug resistant organisms. Further, a microbial community adapts to BAC exposure via a variety of mechanisms, including selective enrichment of BAC-degrading species and amino acid substitutions and horizontal transfer of genes related to BAC resistance and degradation. The metatranscriptomic data suggests that the BAC-adapted microbial community metabolized BACs by cooperative interactions among its members. More specifically, Pseudomonas nitroreducens cleaved (i.e., dealkylated) BACs, metabolized the alkyl chain (the dealkylated product of BACs), and released benzyldimethylamine (the other product of BACs), which was further metabolized by other community members (e.g., Pseudomonas putida).
Collectively, this study demonstrates the role of BACs in promoting antibiotic resistance and advances current understanding of a microbial community degrading BACs. The results of this work have important implications for (appropriate) usage of disinfectants and for assessing, predicting, and optimizing biological engineering processes treating BAC-bearing waste streams.
14
King, Robin K. "The Presence of Pathogenic Bacteria in Recirculating Aquaculture System Biofilms and their Response to Various Sanitizers." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/27185.
Full textAbstract:
Recirculating aquaculture offers a prospect for successful fish farming, but this form of aquaculture presents a great potential for pathogenic microorganisms to become established in the system through the formation of biofilms. Biofilms are capable of forming on all aquaculture system components, incorporating the various microflora present in the water. Pathogenic microorganisms released from the biofilms are capable of causing recurring exposure to disease in both fish and humans. With the increased consumption of raw and rare fish, the presence of these bacteria in or on the fish could lead to ingestion of pathogens. There is also the possibility of cross-contamination during processing. The objectives of this study were to increase the understanding of pathogen incorporation into biofilms in recirculating aquaculture systems and to determine the effectiveness of various sanitizers in eliminating biofilms.
Seven freshwater and two saltwater facilities were sampled, with eight different types of materials tested. Pathogenic bacteria were identified using Bacteriological Analytical Manual methods and rapid commercial test kits. Most of the pathogenic bacteria identified were opportunistic organisms ubiquitous in an aquatic environment. The most significant human pathogens were Bacillus cereus, the Shigella species and the Vibrio species. The major piscine pathogens of concern were Photobacterium damsela, the Vibrio species, and Aeromonas hydrophila. The most significant variation in biofilm pathogens was observed between facilities and not construction material.
Buna-N rubber, polyvinyl chloride (PVC), chlorinated PVC, glass, fiberglass and stainless steel disks were suspended in 79.2 liter (20 gallon) aquariums stocked with Nile tilapia (Oreochromus niloticus). The tanks were inoculated with a known amount of green fluorescent protein (GFP) modified Escherichia coli and samples were removed on days 1,3, 7 and 15. The modified E. coli were isolated on Luria Broth Agar and plate counts were performed under ultraviolet light. There was no significant difference in the growth of the surrogate pathogen on the different materials. The GFP E. coli was isolated in the largest numbers 24 hours after inoculation of the tanks, with an approximate 1-log decrease after day 1. Days 3, 7, and 15 showed equivalent growth of the target organism.
Two sets of disks were suspended in another six 79.2 liter (20 gallon) aquariums. The tanks were inoculated with a known amount of the surrogate pathogen, GFP E. coli, and after 24 hours one set of disks was removed from each tank. The second set of disks was removed and treated by spraying with water, alkaline cleanser, sodium hypochlorite, quaternary ammonium compound, or peracetic acid. Ozone was bubbled directly into one tank to treat another set of disks. The modified E. coli were isolated and counted. Total aerobic plate counts and Enterobacteriaceae counts were performed. Statistical analysis indicated that the type of material had no significant affect on the effectiveness of the sanitizers. It was determined that sodium hypochlorite (99.4591 overall reduction) and peracetic acid (98.8461 % overall reduction) were the most effective sanitizers overall, and ozone (32.9332 % overall reduction) was the least effective.Ph. D.
15
Rajasekaran, L. R. "The mechanism of accumulation of proline and quaternary ammonium compounds and their adaptive significance in tomato (Lycopersicon esculentum, Mill.) and wheat (Triticum aestivum) exposed to salt stress." Adelaide, 1988. http://hdl.handle.net/2440/18866.
Full text
16
Grigonis, Aidas. "Benzalkonio ir metenamino analogų antimikrobinio aktyvumo nustatymas in vitro ir jo priklausomybė nuo aerozolio dalelių krūvio." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070214_152534-59492.
Full textAbstract:
Antibacterial effectiveness in vitro of the original quaternary ammonium compounds that were synthesized in the Laboratory of Biologically active substances was determined and the dependence of this activity upon chemical structure of the compound was established. Also generalisations have been made concerning the regularity of this dependency, the effectiveness of the compounds was compared to benzalkonium chloride, their advantages and disadvantages were discussed. Acute toxicity of the most effective compound was established and compared to that of benzalkonium chloride.
It was found that these compounds showed good antibacterial activity against Gr+ and Gr- bacteria and low toxicity, thus this original data was summarized in the patent Nr. 4712.
For the first time it was found that upon disintegration of quaternary methenamonium compounds new quaternary ammonium compounds, aldehydes and ammonia are produced. The first two of the three show further antimicrobic activity.
Using quaternary ammonium salts and cholrhexydine a biocide for disinfection was created. The created biocide was tested for effectiveness when used for disinfection of air in the premises, horizontal and vertical surfaces. The compound was used in the form of aerosols and electro-aerosols. The research data showed that strong concentrations of Dezinfektas IV are necessary (up to 30%), but small amount of the solution per volume is enough (20-30 ml/m3). Ten times higher concentration is needed for... [to full text]
17
Abdouslam, Nouradin Ali. "Impact of pollution on the dissemination of bacterial genes encoding resistance to quaternary ammonium compounds (QACs) and evidence for co-selection of drug resistance genes in environmental bacteria." Thesis, University of Warwick, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437691.
Full text
18
Zhao, Qian. "Molecular dynamics simulation of interactions between clay minerals and a controlled organic phase." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47650.
Full textAbstract:
Engineered organoclays are 2:1 phyllosilicate soils that have been synthesized with a controlled interlayer organic phase to exhibit enhanced strength, lower compressibility, and stronger retention of organic compounds. Engineered organoclays are highly sorptive, and have a variety of potential engineering applications as sorbents or amendments in engineered earthen barrier systems. Previous studies examined the impact of the organic coating on a soil's physical properties; however, the geochemical behaviors of organoclays, especially their interaction with organic compounds at the micro-scale, remained relatively unquantified. This study investigated the engineering behavior of montmorillonite modified with a variety of quaternary ammonium cations (QAC clays) with controlled structure and density of loading. Molecular dynamics simulations were used to model the surfactant arrangement, geochemical processes in the QAC-clay interlayer, including organic compound sorption and mass transport, as well as the surface electrokinetics of suspended QAC-clay particles. All simulations were carried out based on the combined force field of ClayFF and the Consistent-Valence Force Field to ensure the accuracy of the simulation results, and results yielded insight into the prediction of synthesized QAC-clay behaviors as sorptive material for non-polar organic compounds.
19
Dhainaut, Jérémy. "Vers l’identification d’inhibiteurs de croissance pour la synthèse de cristaux de zéolithes de taille nanométrique." Thesis, Mulhouse, 2012. http://www.theses.fr/2012MULH8452/document.
Full textAbstract:
Les zéolithes sont largement utilisées en catalyse. Un enjeu majeur est d'obtenir des cristaux nanométriques qui offrent des perspectives prometteuses dans la conception de catalyseurs acides plus actifs et plus sélectifs, notamment pour les procédés de conversion des coupes lourdes pétrolières. L'obtention de ces nano-cristaux peut résulter de l'utilisation d'inhibiteurs de croissance. Cette thèse s'est attachée à identifier deux familles de composés organiques limitant la croissance des cristaux. Pour la première, l'inhibition est envisagée par adsorption de composés organiques (polycations, acides aminés...) sur la surface des cristaux en formation. Cette étude a été réalisée en suivant une méthodologie d'expérimentation à haut-débit et a conduit à des cristaux de zéolithe Y (FAU) de 300 nm par l'ajout de L-lysine. La seconde famille est dérivée de l’approche de l’équipe de Ryoo et consiste en l’utilisation de composés bifonctionnels comportant une fonction structurante et une fonction inhibitrice de croissance. Cette étude a démarré par la synthèse de zéolithe MFI. La modélisation moléculaire a permis d'identifier un mono-ammonium alkylé favorisant la formation de nanofeuillets de zéolithe ZSM-5 d'épaisseur voisine de 2 nm. L'étude cinétique a révélé par ailleurs que cette zéolithe est synthétisée à partir d’un polysilicate lamellaire formé in situ. Cette stratégie d'identification, couplée à une méthodologie d'expérimentation à haut débit, a alors été appliquée à la synthèse des zéolithes EMC-1 (FAU) et EMC-2 (EMT), et a conduit à l'élaboration de nouveaux agents structurants et composés bi-fonctionnelsZeolites are widely used in catalysis. One of today’s major challenges is to obtain nanometer-sized crystals, offering promising prospects for the design of more active and more selective acid catalysts, in particular for heavy oil conversion processes. Zeolite nanocrystals can be obtained by using growth inhibitors. This thesis focused on the identification of two families of organic compounds limiting the crystals growth. For the first one, the growth inhibition is favored by the adsorption of organic compounds (polycations, amino acids…) on the surface of growing crystals. This study was conducted using a high-throughput experiment methodology and led to zeolite Y (FAU) crystals of 300 nm by the addition of L-lysine. The second family is derived from Ryoo’s team approach and consists of the use of bifunctional compounds including one structure-directing function and one growth-inhibiting function. This study started with the synthesis of MFI zeolite. The molecular modelling allowed identifying an alkyl mono-ammonium directing the formation of 2 nm-thick nanosheets of zeolite ZSM-5. The kinetic study revealed that this zeolite is synthesized from a lamellar polysilicate formed in situ. This identification strategy, coupled to a high-troughput experiment methodology, was applied to the synthesis of zeolites EMC-1 (FAU) and EMC-2 (EMT) and conducted to the elaboration of new structure-directing agents and their bifunctional counterparts
20
Regis, Romulo Rocha. "Análise das propriedades biológicas de um monômero antimicrobiano para aplicação em prótese dentária." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/58/58131/tde-19032010-120543/.
Full textAbstract:
A resina acrílica para base de próteses removíveis é capaz de acumular biofilme e assim favorecer o aparecimento de diversos problemas na cavidade bucal dos usuários de próteses. A imobilização de um agente antisséptico na matriz polimérica tem potencial preventivo frente a esse acúmulo, mas necessita de maior investigação. O objetivo deste estudo foi avaliar as propriedades biológicas do brometo de metacriloiloxiundecilpiridínio (MUPB), um composto antisséptico capaz de copolimerizar-se com as resinas acrílicas. Foram determinadas as concentrações inibitória e fungicida/bactericida mínimas (CIM, CFM/CBM) do MUPB frente às espécies Candida albicans, Candida dubliniensis, Candida glabrata, Lactobacillus casei, Staphylococcus aureus e Streptococcus mutans, em comparação ao cloreto de cetilpiridínio (CCP). A seguir, investigou-se a citotoxicidade do MUPB em fibroblastos, comparando-o com o metil metacrilato (MMA). A avaliação da atividade antimicrobiana de diferentes concentrações do MUPB em massa (0, 0,3% e 0,6%) incorporado em uma resina acrílica termopolimerizável para base de próteses foi realizada por meio de testes de difusão em disco e quantificação de unidades formadoras de colônia (UFC) aderidas à resina após contato com suspensões de cada micro-organismo. A adesão microbiana também foi avaliada por microscopia eletrônica de varredura. Comparações entre o MUPB e as demais substâncias, bem como entre as concentrações incorporadas na resina, foram realizadas com α=0,05. O MUPB apresentou CIM inferior ao CCP para C. dublinienses e S. mutans (P=0,046 e 0,043, respectivamente). Para as demais espécies, as diferenças não foram significantes. Para a CFM/CBM, só foi encontrada diferença significante para C. albicans (P=0,046). O MUPB não polimerizado mostrou-se em torno de 20 vezes mais citotóxico que o MMA. Independente da concentração incorporada e da espécie, não houve formação de halo de inibição em torno dos espécimes. A incorporação do MUPB só influenciou na adesão de C. albicans (P=0,003), com menores contagens de UFC para o grupo com 0,6%. Conclui-se que o MUPB não polimerizado tem capacidade antimicrobiana próxima à do CCP, e alta citotoxicidade, se comparado ao MMA. A atividade antimicrobiana, após incorporação em uma resina acrílica para base de prótese, não depende de sua eluição, porém apresentou-se restrita à C. albicans.Acrylic resins for removable denture base are capable of accumulating biofilm and thus favor the appearance of various problems in the edentulous oral cavity. An antiseptic agent immobilized within the polymeric matrix has a preventive potential against this accumulation, but requires further investigation. The aim of this study was to evaluate the biological properties of methacryloyloxyundecylpyridinium bromide (MUPB), an antiseptic monomer capable of copolymerizing with acrylic resins. The minimum inhibitory and fungicidal/bactericidal concentrations (MIC, MFC/MBC) of MUPB were determined against the species Candida albicans, Candida dubliniensis, Candida glabrata, Lactobacillus casei, Staphylococcus aureus and Streptococcus mutans, in comparison with cetylpyridinium chloride (CCP). After this, the cytotoxicity of MUPB was investigated in fibroblasts, compared with methyl methacrylate (MMA). The antimicrobial activity of different concentrations of MUPB (0, 0.3% and 0.6% w/w) incorporated into a heat polymerized denture base acrylic resin was evaluated by means of disk diffusion tests, and the CFUs adhered to the resin after contact with suspensions of each microorganism were quantified. Microbial adhesion was also evaluated by scanning electron microscopy. Comparisons were made between MUPB and the other substances, as well as between the concentrations incorporated into the resin (α=.05). MUPB presented a lower MIC than CCP for C. dubliniensis and S. mutans (P=.046 and .043, respectively). For the other species, the differences were not significant. For MFC or MBC, significant difference was found only for C. albicans (P=.046). Non polymerized MUPB was shown to be 20 times more cytotoxic than MMA. Irrespective of the concentration incorporated and the species, there was no growth of inhibition halo around the specimens. The incorporation of MUPB only influenced the adhesion of C. albicans (P=.003), with lower CFU counts for the group with the concentration of 0.6%. It was concluded that non polymerized MUPB has an antimicrobial capacity close to that of CCP, and high cytotoxicity when compared with MMA. The antimicrobial activity after incorporation within a denture base acrylic resin did not depend on its elution, but was shown to be restricted to C. albicans.
21
Talbaoui, Ahmed. "Etude en microscopie électronique par cryofracture des systèmes chlorures et bromure de dodécylamine-eau." Rouen, 1989. http://www.theses.fr/1989ROUES006.
Full textAbstract:
Après une importante bibliographie concernant les phases lyotropes et les techniques cryogéniques en microscopie électronique, l'auteur expose les résultats de ses observations en cryofracture sur les systèmes du titre. Description de la transition lamellaire-nématique et comparaison aux modèles présentés par d'autres auteurs. Discussion de la validité de la technique de cryofracture pour ce type de systèmes
22
Gulea, Mihaela. "Réarrangement [2,3]-sigmatropique de Wittig d'anions alpha-phosphoriques alpha-hétérosubstitués. Synthèse asymétrique de phosphonates alpha-hydroxylés ou alpha-aminés." Rouen, 1997. http://www.theses.fr/1997ROUES003.
Full textAbstract:
Ce travail décrit la première étude du réarrangement [2,3]-sigmatropique de Wittig qui utilise le groupe phosphonate pour stabiliser le carbanion alpha-hétérosubstitué. Cette réaction constitue une nouvelle voie d'accès à des phosphonates alpha-hétérosubstitués, avec des possibilités de contrôle stéréochimique. Le réarrangement [2,3]-sigmatropique des carbanions d'(alpha-allyloxy)-méthylphosphonates a permis d'obtenir des alpha-hydroxyphosphonates gamma, delta-insaturés diversement substitués. Les carbanions d'éthers allyliques alpha-phosphonylés alpha-carboxylés ou alpha-diphosphonylés conduisent, via les alcoolates intermédiaires réarrangés au phosphate ou au phosphate-phosphonate respectivement. Le réarrangement aza-[2,3]-sigmatropique de Wittig des carbanions dérivés du (N-allyl-N-phénylamino) méthylphosphonate de diéthyle ou des aminophosphonates allyliques dont l'atome d'azote est protégé par un groupe électroattracteur, n'a pas pu être mis en évidence. Par contre, les ylures résultant de la métallation des sels d'ammonium alpha-phosphonylés dont l'azote porte un groupe allylique se réarrangent en alpha-(N,N-diéthylamino) alcénylphosphonates correspondants. La réaction a été étendue en série propargylique et benzylique, ainsi qu'en série des ylures des alpha-aminophosphonates alpha-phosphonylés ou alpha-carboxylés, conduisant à de nouveaux phosphonates polyfonctionnalisés. Utilisant le groupe dimenthylphosphonate comme auxiliaire chiral, nous avons obtenu par réarrangement [2,3]-sigmatropique de Wittig de l'allyloxyméthylphosphonate avec une très bonne diastéréosélectivité (de = 92 %).
23
Mofaddel, Nadine. "Contribution à l'étude de systèmes quaternaires : exploitation de sulfates alcalins et dédoublement de molécules chirales par formation de diastéréoisomères." Rouen, 1989. http://www.theses.fr/1989ROUES013.
Full textAbstract:
Dans le cadre de la détermination des domaines de cristallisation d'espèces définies dans un système d'ordre élevé, deux systèmes quaternaires sont étudiés. Le premier système est Na2So4 - K2SO4 – (NH4)2SO4 – H2O : l'isotherme 18°C est dressé, définissant les domaines de stabilité des différentes phases rencontrées. Le deuxième système est le système réciproque: l'isotherme 20°C montre la possibilité de dédoublement d'un composé racémique. Une étude critique des travaux antérieurs est apportée
24
Bennis, Khalil. "Etude de l'adsorption et de la reduction electrochimique sur electrode de mercure de quelques cetones en presence de tensio-actifs en milieu aqueux." Clermont-Ferrand 2, 1988. http://www.theses.fr/1988CLF2E406.
Full textAbstract:
Etude de la reduction electrochimique de l'acetophenone, l'oxyde de mesityle et l'ethylideneacetone en milieu aqueux en presence d'agents de surface anioniques (laurylsulfate de sodium), d'agents de surface cationiques (bromure de benzyltrimethylammonium et bromure de cetyltrimethylammonium) et d'agents de surface non ioniques (brij 35 et poly(oxyethylene))
25
Souabi, Salah. "Etude de l'adsorption de tensioactifs cationiques sur charbon actif influence de coadsorbats /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376186543.
Full text
26
Aous, Soad. "Synthèse de cyclopendants aminophosphorés : complexes d'ions paramagnétiques à finalité biomédicale." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10057.
Full textAbstract:
Les resultats de ce travail a finalite biomedicale s'organisent selon trois axes : - synthese de nouveaux cyclopendants et de complexes polyfonctionnels de gd iii, en serie macrocyclique et bismacrocyclique, les podants etant organophosphores. Nous avons ainsi obtenu le dotmp -acide 10,13-dioxo-1,4,7-triazacyclopentadecane-4,7,10-tri(methylenephosphonique) avec un cycle bifonctionnel dioxo-triaza et des composes modeles, precurseurs de dendrimeres : le ttap, -acide 1,4,8,11-tetraazacyclotetradecane-1-acetique-4,8,11-tri(methylenephosphonique) cyclopendant a podants mixtes phosphonique et carboxylique, ce dernier devant permettre la fixation du dendrimere a un anticorps monoclonal et le bmp, -acide 1,1'-1,4-phenylenebis(methylene)bis1,4,8,11-tetraazacyclotetradecane-4,8,11-tri(methylenephosphonique) cyclopendant bismacrocyclique a podants organo-phosphores, unite de base du dendrimere. La cinetique de complexation de gdiii par ces ligands est rapide. - visualisation par spectrometrie de masse des complexes alcalins et de tetramethylammonium qui se forment lors des dosages potentiometriques de polyacides polyfonctionnels et evaluation de leur stabilite. Leur formation a ete confirmee par rmn du sodium. Une simulation a permis de montrer les consequences de portee generale sur la ph-metrie que cela induit, en particulier la tres grande incertitude sur les constantes de stabilite des acides et complexes - incertitude qui peut atteindre 1 a 2 unites de ph - mais aussi le fait que dans les calculs doivent etre pris en compte les especes complexees et leurs constantes de stabilite. - etude physico-chimique du dotmp, du ttap et de leur complexes de gadolinium, qui a ete realisee en integrant les resultats precedents. Les constantes de protonation ont ete determinees par potentiometrie et par la sequence de protonation ; comme pour les cyclopendants aminophosphores analogues, deux des azotes macrocycliques sont tres basiques. La stabilite des complexes gdttap et gddotmp aux ph physiologiques permet d'envisager de les tester comme agent de contraste chez l'animal.
27
Zheng, Yu. "The biodegradation of quaternary ammonium compounds by mould fungi." Thesis, 1995. http://hdl.handle.net/2429/4220.
Full textAbstract:
Didecyldirhethylarrmionium chloride (DDAC) has been described as one of the most
effective quaternary ammonium compound (QAC) wood preservatives, based on laboratory
experiments. Subsequently, QAC-treated stakes failed rapidly in field tests. It was suggested
that the degradation of QACs by mould and stain fungi had reduced the efficacy of QACs.
This thesis describes a study of the role that moulds play in limiting the performance of
DDAC.
Fungi were isolated from DDAC-treated stakelets placed in a field test site at UBC.
Other fungal strains were obtained from culture collections. A comparison was made of their
tolerance and ability to degrade DDAC. Experiments were performed both in solid malt agar
and Vogel liquid media with, and without, DDAC. It was found that tolerance and ability to
degrade DDAC shown by the fungal strains were common properties of many of the moulds
studied.
The metabolites produced by the action of moulds on DDAC were extracted by
methylene chloride and analyzed by high performance liquid chromatography (HPLC) and
gas chromatography-mass spectrometry (GC-MS). The results showed that DDAC had been
degraded by mould fungi, either by fission of the C-N bond or co-and (3-oxidation of the decyl
group.
Electrophoresis was performed to try to identify additional proteins arising from the
presence of DDAC. New proteins bands were obtained in the extracellular supernatant. The
DDAC concentration in liquid media was decreased when inoculated and incubated with the extracellular supernatant recovered from Verticillium bulbillosum grown in liquid media
containing 250 ppm DDAC. No new proteins were obtained in the intracellular extract, and
no degradation of the DDAC was recorded when the intracellular supernatant was incubated
with DDAC. This suggested that DDAC degradation took place outside the fungal cell wall.
28
Valladao, Marilin. "Growth of lactococci relative to antibiotic and quaternary ammonium compounds." Thesis, 1990. http://hdl.handle.net/1957/37622.
Full textAbstract:
The work presented in this thesis is concerned with the
effect of several antibiotics and quaternary ammonium
sanitizers upon growth of lactic acid bacteria. Section I
reports the purification of beta-lactamase from Lactococcus
cremoris PR-108, by ion exchange chromatography, using the
chromogenic substrate pyridine-2-azo-p-dimethylaniline
(PADAC) as the enzymatic indicator. Section II reports a
study of the influence of antibiotics on lactococcal growth,
where the effects of incubation time, culture dilution and the
use of seeded and spread agar plate techniques are
investigated. These studies were extended, in section III,
to include investigations of the effect of quaternary ammonium
base sanitizer (Ster-bac) on lactic starters. In addition,
this section describes an reverse phase high performance
liquid chromatography assay for the detection of quaternary
ammonium compounds in milk.Graduation date: 1991
29
Bull, Jennifer Patricia. "Immunoassays for two quaternary ammonium compounds, benzyldimethyldodecylammonium chloride (BDD12AC) and didecyldimethylammonium chloride (DDAC)." Thesis, 1997. http://hdl.handle.net/2429/7604.
Full textAbstract:
A competitive enzyme-linked immunosorbent assay (CELISA), based on polyclonal
antibodies, was developed to measure benzyldimethyldodecylammonium chloride
(BDD₁₂AC), a component of benzalkonium chloride (BAK). The polyclonal antibodies
recognized free benzyldimethyldodecylammonium bromide (BDD₁₂AB), with a 50%
inhibition (IC₅₀) of 0.66 µg/mL and a detection limit of 0.043 µg/mL. The two other
components of BAK, benzyldimethyltetradecylammonium chloride (BDT₁₄AC) and
benzyldimethylhexadecyl-ammonium chloride (BDH₁₆AC), as well as other
alkyldimethylbenzylammonium compounds (ADBACs), were recognized to varying degrees
by the antibodies. The antibodies also recognized a commercial BAK compound (77% C₁₂:
23% C₁₄). The antibodies cross-reacted minimally with other compounds such as fatty acids
and alcohols, amino acids, amines, and short-chain quaternary ammonium compounds.
CELISA and HPLC were used to quantify BDD₁₂AB and BAK (Aldrich) spikes in milk
solutions. BDD₁₂AC was also measured in five commercial products containing BAK, using
both analyses. HPLC analysis correlated well with CELISA analysis for these commercial
products.
CELISAs were also developed for didecyldimethylammonium chloride (DDAC)
using three novel haptens. The three resulting antisera recognized DDAC to different
degrees, with IC₅₀'s ranging from 0.05 µg/mL to 17.2 µg/mL. Cross-reactivity with
compounds representing DDAC's different epitopes were observed for the three sera at
varying degrees. The antisera also showed varying degrees of susceptibility to detergent
effects, where one serum cross-reacted more with sodium dodecyl sulfate (SDS) than DDAC. Performance of one of the sera raised against DDAC was a marked improvement
over a previously described anti-DDAC serum, produced by Chen et al. (1995). This new
antiserum could be used to detect DDAC in environmental samples since the IC₅₀ is 50 ppb,
well under the discharge limit of 700 ppb.
30
Owens, Gary 1967. "Nitrate selective resins : interaction of monomeric and polymeric quaternary ammonium compounds with nitrates / by Gary "Peter" Owens." 1995. http://hdl.handle.net/2440/18592.
Full textAbstract:
Copies of author's previously published articles inserted.Errata sheet posted inside back cover.
xiii, 156, [63] leaves : ill. ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Aims to discover the basic principles that govern the selective removal of nitrates from drinking water by ion-exchange resins.
Thesis (Ph.D.)--University of Adelaide, Dept. of Chemistry, 1995
31
Rodriguez, Ana. "Effect of organic acids and quaternary ammonium compounds on survival of Salmonella serovars with SGI1- mediated multi-antibiotic resistance." 2009. http://purl.galileo.usg.edu/uga%5Fetd/rodriguez%5Fana%5Fl%5F200912%5Fms.
Full text