Dissertationen zum Thema „Ammonia compound“

L’objectif de cette thèse doctorale fut la synthèse de composés polyazotés qui serviraient comme matériaux énergétiques du futur. Afin d’y arriver, les propriétés physico-chimiques de l’azote pur ainsi que des mélanges binaires xénon-azote, hydrogène-azote ainsi que lithium-azote furent étudiés à des pressions et températures extrêmes. Lors de la compression de l’azote pur jusqu’à environ 250 GPa et chauffé à 3300 K, une nouvelle forme d’azote polymérique constituée d’anneaux N6 interconnectés fut obtenue. À basse pression, les études du mélange Xe-N2 permirent de découvrir un composé de van der Waals de stoechiométrie Xe(N2)2. À plus haute pression et température (150 GPa et 2500 K) un solide composé de xénon et d’azote simplement lié fut obtenu. L’étude du système N2-H2 se focalisa sur le composé N2(H2)2. Sa structure complexe fut déterminée et, une réaction chimique vers 50 GPa ayant comme produit de réaction des azanes (NxHx+2) fut mise à jour. Il fut constaté que l’azane ammoniac (NH3), principalement obtenu, se transforme en hydrazine (N2H4)—pourtant a priori moins stable thermodynamiquement—lors de la décompression des échantillons réagit. Enfin, l’étude du système Li-N2 révéla une chimie remarquable entre ces deux éléments. Une grande variété d’anions d’azote fut obtenue, notamment N3-, [N2]~2 [N2]~1 et N5-. En particulier, le pentazolate de lithium (LiN5), contenant l’anion pentazolate hautement énergétique, put être récupéré aux conditions ambiantes. Ce composé est le premier composé polyazoté à haute densité d’énergie produit par pression et récupéré aux conditions ambiantes, démontré le potentiel des synthèses hautes pressions pour ce type de matériau
The goal of this thesis is to synthesize novel polynitrogen compounds by pressure as the next-generation high energy density materials (HEDM). To achieve this, the physico-chemical properties of pure nitrogen as well as the xenon-nitrogen, hydrogen-nitrogen and lithium-nitrogen mixtures were studied under extreme pressure and temperature conditions. In the case of the compression of pure nitrogen, a novel polymeric nitrogen solid composed of interconnected chains of N6 rings was produced at 250 GPa and 3300 K. The low pressure Xe-N2 investigation revealed the formation of a stoichiometric Xe(N2)2 van der Waals compound. Above 150 GPa and 2500 K a xenon-polynitrogen material was observed. The N2-H2 study, focusing on the characterization and high-density behavior of the N2(H2)2 van der Waals compound, uncovered its pressure-induced chemical reaction near 50 GPa into azanes (NxHx+2), with ammonia (NH3) as the main constituent. Intriguingly, decompression of the reacted sample resulted, below 10 GPa, in the transformation of ammonia into its thermodynamically less stable counterpart hydrazine (N2H4). Lastly, the Li-N2 system proved to be of great interest due to the large array of anionic nitrogen moieties discovered (N3-, [N2]~2 [N2]~1 and N5-). In particular, lithium pentazolate (LiN5), containing the elusive energetically-rich pentazolate anion, was synthesized above 45 GPa and 2500 K. Moreover, it could be retained down to ambient conditions. It is the first polynitrogen HEDM produced by high pressure and retrieved down to ambient conditions. These results demonstrate the potential of high pressure for the synthesis of industrially relevant HEDM

Philosophiae Doctor - PhD
Background: 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.

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

Includes abstract.
Includes bibliographical references.
The FT synthesis has been used predominantly for production of automotive fuels. This has made the financial benefit from the FT process heavily reliant on crude oil prices. Increasing the financial viability of the process has been achieved by improving production methods, production of alternative products such as waxes, lubricants, as well as valuable chemicals such as olefins and oxygenates. In an attempt to produce additional chemicals in the FT reaction, this work investigates the synthesis of nitrogen containing compounds via ammonia addition to a low temperature, low pressure, slurry reactor using an unsupported, potassium-promoted, precipitated iron catalyst. The process is subjected to various ammonia contents in the feed.

The aim of the work described in this thesis was to study the removal of ammonium ions from water by ion exchange. The classical technique is to use biological nitrification and denitrification to convert ammonia into nitrogen gas. Removal by ion exchange offers a number of advantages, such as the ability to handle shock loadings and to polish water to a very high specification. The ion exchanger used in this project was clinoptilolite, a naturally occurring zeolite. Previous research has included characterisation of clinoptilolite, the effect of other common cations on uptake, biological regeneration, and a few other studies. A comparison with other exchangers was also conducted. Much of the available literature is concerned with clinoptilolite and occasionally with mordenite, however modern ion exchangers are polymer based. Two polymeric ion exchangers (Dowex 50w-x8, and Purolite MN500) were evaluated in this project. The main scope of this thesis was to look at the effect that organic pollutants has on ammonium ion removal during ion exchange. The results of batch equilibrations of NH4+ and the three exchanger resins can be seen in chapter 4.0. They show that the presence of an organic compound enhanced the uptake of NH4+ in most cases onto clinoptilolite and Purolite MN500. There was no apparent uptake onto Dowex 50w-x8. Further experiments with a sample of real industrial wastewater (woolscour wastewater) showed varied results, showing that each site should carry out its own pilot scale testing during plant design. Other experimental work showed that the exchanger resins adsorb little or none of the organic compounds in solution. These results can be seen in chapter 5.0. ii Removal of ammonia from wastewater by ion exchange in the presence of organics. Studies in a packed column showed that the presence of organic compounds had little or no effect on NH4+ removal. There was however an increase in capacity after each regeneration of the bed and continued removal after breakthrough. The same results were achieved in the control experiment with no organic compounds present, hence these results are not related to the presence of an organic compound. The presence of NH4+ and various compounds did however provide micro-organisms with substrates from which to grow causing hydraulic difficulties in the column. See chapter 6.0 for these results. The final section of experimental work studied whether the presence of organic compounds changed the rate of uptake of NH4+. The results in chapter 7.0 show that there was no effect on the rate of NH4+ uptake.

Etude de l'action de l'ammoniac sur les composes d'insertion graphite-chlorures metalliques. Suivie de la reaction in sistu en temps reel par diffraction des neutrons. Formation de microcristallites d'ammoniacates au sein du reseau cristallin du graphite. Avantage de cette texture par rapport a l'ammoniacate seul en vue de son application aux procedes de conversion thermochimique de l'energie. L'etude cinetique des reactions mises en jeu

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1986.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE
Vita.
Includes bibliographies.
by Richard K. Helling.
Sc.D.

The Fischer-Tropsch synthesis (FTS) process, better known for its ability to produce synthetic fuel via the hydrogenation of CO, has shown potential to produce valuable chemicals when ammonia is added to the feed. In this work certain aspects of the pathway to the formation of N-containing compounds that form when NH₃ is added during FTS, using mostly iron based catalysts is investigated. In addition, the effect this has on the FTS reaction itself is evaluated. To achieve this goal, both theoretical and experimental techniques are used in this study. The CO adsorption and dissociation reactions are assumed to be important elementary reactions for many proposed FTS pathways. In the theoretical part of this thesis, spin-polarized periodic density functional theory (DFT) calculations are employed to study aspects of the initial stage of the pathway on a model Fe(100) surface. Considering the formation of N-containing hydro- carbons, one would assume that NH₃ initially adsorbs and dissociates on the catalyst surface, which could take place in the presence of CO. The surface chemistry of these adsorbates is well studied both experimentally and theoretically, but their co-existence has not yet been evaluated on model Fe surfaces. Initially a platform is generated by calculating the individual potential energy surfaces (PES) for the decomposition of CO and NH₃ on Fe(100) at a coverage of ϴ = 0.25 ML. These calculations provided the basis for comparing the adsorption and dissoci- ation profiles of CO and NH₃ on the Fe(100) surface via the use of the same computational methodology, and importantly making use of the same exchange correlation functional (RPBE) for both adsorbates. Furthermore, it was desired to evaluate the kinetics and thermodynamics of the NH₃ decomposition on the Fe(100) surface at relevant temperatures and pressures (by combining the DFT results with statistical thermodynamics) to better understand the role of NHₓ surface species involved in the pathway to the formation of the N-containing compounds on a model catalyst surface. The DFT results that are reported for the individual decomposi- tion PES for CO and NH₃ were generally found to be in close agreement with what has been reported in previous DFT studies and deduced experimentally for the relevant adsorption and decomposition pathways. The resulting Gibbs free energies for the PES suggests that NH₂ may be kinetically trapped on the Fe(100) surface at a coverage of ϴ = 0.25 ML and the reaction conditions (T = 523 K and p*NH₃ = 0.2 bar) where NH₃ is co-fed with synthesis gas during FTS. The individual adsorptions of CO and NHₓ (with x = 3, 2, 1, 0) were compared to their coadsorbed states, by calculating the heat of mixing (ΔEmix) and the activation barriers (Eₐ) for CO dissociation in the presence and absence of the NHₓ surface species on the Fe(100) sur- face. Similar to the individual adsorption of NH₃, the 0 K regime inherent to DFT calculations is bridged by calculating the Gibbs free energy of mixing for CO + NH₃ on Fe(100) at higher temperatures. Both repulsive and attractive interaction energies were calculated for the various coadsorbed states (CO + NHₓ on Fe(100)) and similarly some configurations resulted in an energetically favored or unfavored heat of mixing. The activation barrier for CO dissociation was lowered when coadsorbed with NH₃ and NH₂, and raised when coadsorbed with NH and N. With all the coadsorbed structures the CO dissociation reaction became more endothermic. Previous experimental studies have shown a concomitant reduction in oxygenate selectivity with an increase in the selectivity for N-containing compounds, when NH₃ is added during FTS. It is well-known that oxygenates undergo secondary reactions when using iron-based catalysts in FTS. In addition, the catalyst used in aforementioned studies (precipitated Fe/K) are active for the amination reactions of oxygenates. It is therefore hypothesized that some oxygenates pro- duced via the primary FTS pathway are converted to N-containing compounds via a secondary reaction. The experimental part of this thesis is therefore aimed at testing this hypothesis. A base case study included a comparison between a Fe-catalyzed slurry phase FTS reaction and a FTS reaction with all parameters remaining unchanged, except for the addition of 1 vol % NH₃ to the syngas (CO + H₂) feed. The activity (CO and H₂ conversion) data collected did not reveal any appreciable loss in the rate of the FTS reaction when 1 vol % NH₃ was added and steady state was reached (, that is after 48 hours time on stream (TOS)). A slower carburization period was however observed when comparing the CO conversion during the first 24 hours TOS, and further supported by the slow increase in CO₂ selectivity during the same period. The use of two-dimensional gas chromatography (GC × GC-TOF/FID) allowed for the discovery of a formation of a range of secondary and tertiary amines, not reported in previous studies. The expected loss in oxygenate selectivity was observed and further probed by co-feeding 1-octanol with the feed (CO + 2H₂ + 1 vol % NH₃) via a saturator. These results clearly indicated a significant loss in oxygenate formation as a result of secondary conversion to N-containing compounds. Questions regarding the stability of aliphatic nitriles prompted the co-feeding of nonanitrile under similar conditions. The results obtained after co-feeding nonanitrile, sug- gests that nonanitrile is readily converted to secondary and tertiary amines and that the ratios of aliphatic alcohols and nitriles are close to equilibrium. The use of CO₂ as carbon source, the investigation of the product spectrum at higher space velocities and the use of Rh-based catalysts, when NH₃ is added during FTS were included in shorter studies. The combination of these results, adds to the knowledge pool for the case where NH₃ is present in the FTS regime, as a poison or reactant. Additional information regarding the path to the formation of N-containing compounds was obtained via the detailed analysis of the product spectra with two-dimensional gas chromatography and the subsequent co-feeding reactions. The results ob- tained via co-feeding reactions, can be used to devise strategies to increase the selectivity of the desired N-containing compounds.

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.

Floodplain lakes are wetlands which receive flood waters from nearby rivers or other sources. Water samples were taken from floodplain lakes near the Illinois River, the Mississippi River, and the Cache River in Southern Illinois. Fluorescence in situ hybridization (FISH), spectrophotometry, and gene probes were used to investigate the effect of nutrient and chemical concentrations on the abundance of nitrifying bacteria; specifically ammonia-oxidizing Nitrosococcus and Nitrosomonadales and nitrite-oxidizing Nitrospira and Nitrobacter. Nitrosococcus was the dominant ammonia-oxidizing bacteria at each river system. Nitrospira and Nitrobacter had similar average abundances. Nitrosococcus abundances showed a significant positive correlation with nitrate (NO3-) (R2= 0.247, P=0.05, 95% confidence R2≥0.199) and a positive trend with nitrite (NO2-) (R2= 0.194, P=0.10, 90% confidence R2≥0.125). Nitrosomonadales abundance positively correlated with temperature (R2= 0.530, P=0.05, 95% confidence R2≥0.510). Nitrospira abundances positively correlated with ammonium (NH4+) (R2= 0.265, P=0.05, 95% confidence R2≥0.199), NO2- (R2= 0.372, P=0.05, 95% confidence R2≥0.199), and NO3- (R2= 0.482, P=0.05, 95% confidence R2≥0.199). None of the target bacterial abundances significantly correlated with pH or dissolved inorganic phosphate.

Recently, ammonia borane has increasingly attracted researchers’ attention because of its merging applications, such as organic synthesis, boron nitride compounds synthesis, and hydrogen storage. This dissertation presents the results from several studies related to ammonia borane. The pressure-induced tetragonal to orthorhombic phase transition in ammonia borane was studied in a diamond anvil cell using in situ Raman spectroscopy. We found a positive Clapeyron-slope for this phase transformation in the experiment, which implies that the phase transition from tetragonal to orthorhombic is exothermic. The result of this study indicates that the rehydrogenation of the high pressure orthorhombic phase is expected to be easier than that of the ambient pressure tetragonal phase due to its lower enthalpy. The high pressure behavior of ammonia borane after thermal decomposition was studied by in situ Raman spectroscopy at high pressures up to 10 GPa. The sample of ammonia borane was first decomposed at ~140 degree Celcius and ~0.7 GPa and then compessed step wise in an isolated sample chamber of a diamond anvil cell for Raman spectroscopy measurement. We did not observe the characteristic shift of Raman mode under high pressure due to dihydrogen bonding, indicating that the dihydrogen bonding disappears in the decomposed ammonia borane. Although no chemical rehydrogenation was detected in this study, the decomposed ammonia borane could store extra hydrogen by physical absorption. The effect of nanoconfinement on ammonia borane at high pressures and different temperatures was studied. Ammonia borane was mixed with a type of mesoporous silica, SBA-15, and restricted within a small space of nanometer scale. The nano-scale ammonia borane was decomposed at ~125 degree Celcius in a diamond anvil cell and rehydrogenated after applying high pressures up to ~13 GPa at room temperature. The successful rehydrogenation of decomposed nano-scale ammonia borane gives guidance to further investigations on hydrogen storage. In addition, the high pressure behavior of lithium amidoborane, one derivative of ammonia borane, was studied at different temperatures. Lithium amidoborane (LAB) was decomposed and recompressed in a diamond anvil cell. After applying high pressures on the decomposed lithium amidoborane, its recovery peaks were discovered by Raman spectroscopy. This result suggests that the decomposition of LAB is reversible at high pressures.

Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第19196号
農博第2135号
新制||農||1034(附属図書館)
学位論文||H27||N4942(農学部図書室)
32188
京都大学大学院農学研究科森林科学専攻
(主査)教授 吉村 剛, 教授 髙野 俊幸, 教授 渡邊 隆司
学位規則第4条第1項該当

This thesis details investigations into the generation and synthetic utility of α,β-unsaturated acyl ammonium intermediates using isothioureas as Lewis base organocatalysts to generate a range of heterocyclic products. Initial investigations focussed on the development of a Michael addition-lactonisation protocol utilising α,β-unsaturated acyl ammonium intermediates (generated in situ from HBTM 2.1 and α,β-unsaturated homoanhydrides) and a range of 1,3-dicarbonyl nucleophiles. Products could be isolated as lactones or as ring-opened highly functionalised esters, giving good yields and excellent enantioselectivity. 1,3-Diketones were shown to generate a mixture of regioisomers and whereas 1,3-ketoesters afforded only a single regioisomer. A crystal structure of an α,β-unsaturated acyl ammonium intermediate was obtained that clearly demonstrated steric blocking of the Si- face of the alkene by the catalyst stereodirecting groups, therefore it can be postulated that enantiocontrol in the addition occurs by selective nucleophilic addition from the Re- face. α,β-Unsaturated acyl ammonium species were then shown to participate in asymmetric annulation processes with benzazole nucleophiles to afford highly functionalised heterocyclic products, with both lactone and lactam formation observed. The relationship between nucleophile structure and process regioselectivity was investigated and it was demonstrated that benzothiazole and benzimidazole nucleophiles afforded preferential N-cyclisation to give lactams whilst benzoxazoles exhibited O-cyclisation to form lactones. It was also possible to influence the regioselectivity by changing the electronic properties of the acyl group (R'). Due to the reactivity of this class of nucleophiles it was possible to access products with quaternary centres. Palladium-catalysed cross coupling reactions were also successful on 3-bromo substituted lactams, demonstrating the potential for further derivatising these interesting heterocyclic products. Finally, a cascade protocol was developed that employed Michael-Michael-lactonisation steps to give tricyclic products from enone malonate nucleophiles and α,β-unsaturated acyl ammonium intermediates (generated in situ by addition of HBTM 2.1 into acid chlorides). Interestingly, the reaction showed higher enantioselectivity at elevated temperatures (70 ˚C) and moderate regioselectivity (1,4- vs. 1,2-addition), which could not be improved after extensive screening. A range of lactones was isolated in moderate yields and enantioselectivity.

This thesis describes expansion of the ability of isothioureas to act as organocatalysts in formal [2+2]-, [3+2]- and [4+2]-cycloadditions between carboxylic acids and various acceptors via Type I ammonium enolate intermediates. Chapter 2 describes the optimisation and investigation of [2+2]-cycloadditions from ammonium enolates and N-sulfonylimines as the two components. The development of this methodology allows successful access to highly stereodefined β-lactams and, following in situ ring-opening, β-aminoesters. The products are obtained from either preformed homoanhydrides or directly from carboxylic acids, using open flask conditions, from simple, bench-stable starting materials and is scalable. A variety of anti-β-lactams (21 examples, 46-68% yield, up to >95:5 dr, 21->99% ee) and β-aminoesters (9 examples, 44-74% yield, up to >95:5 dr, 68-92% ee) were accessed in moderate yield, excellent diastereo- and good enantioselectivity. This represents an improved route to anti-β-lactams over previously described ketene and N-triflyl imine based methods. Chapter 3 subsequently describes studies focussed on the use of ester surrogates in the formal [4+2]-cycloaddition reactions of isothiourea generated Type I ammonium enolates. Iso-propylphosphonate 163 proved highly effective as the four-component in this process, which following the in situ ring-opening of the initial dihydropyranone product allowed isolation of a range of novel diester products which were previously unobtainable using this methodology. The products were accessed in moderate to excellent yields, excellent diastereo- and enantiocontrol (9 examples, 12-63% yield, up to >95:5 dr, 67-99% ee) with this process also amenable to a large scale. Furthermore, selective reduction and acid-catalysed cyclisation allowed access to δ-lactone products in good yield with retention of stereocontrol. Finally, Chapter 4 describes work on isothiourea-catalysed formal [3+2]-cycloadditions of oxaziridines and acetic anhydrides gave access to stereodefined five-membered oxazolidin-4-one heterocycles. In this case, the use of preformed homoanhydrides and an inorganic base was imperitive to avoid reduction of the oxaziridine starting material. The oxazolidin-4-one products could be accessed in excellent yield and ee however poor dr (13 examples, 63-96% yield, up to 59:41 dr anti:syn, up to >99% ee for both diastereoisomers). Following isolation, reduction of these heterocycles allowed access to enantioenriched diols with little loss in stereocontrol. Mechanistic analysis has shown that an improvement in diasterocontrol can be obtained by the use of an enantioenriched oxaziridine, demonstrating the stereospecificity of this process.

Urinary catheters are indispensable in healthcare and, with an ageing population, their use will continue to increase. However, they are commonly associated with colonisation and urinary tract infections (UTIs) caused by the attachment of bacteria to the catheter surface. Application of a novel cationic compound as a catheter coating may have a significant impact on the costs associated with treatment of UTIs and reduce the need for catheter replacement, as well as decreasing the number of UTI associated morbidity and mortality. Cationic compounds in particular are known to interact with the negatively charged outer membrane of bacteria, therefore have a broad spectrum of activity. The purpose of this study was to source and evaluate a novel cationic antimicrobial for use as a potential coating to impede biofilm formation on urinary catheters, and to investigate the cellular response to the selected lead compound. This research has demonstrated that the antimicrobial activity of commercially available Byotrol™ was superior to that of polyamines and quaternary ammonium compounds that were screened. Using high-throughput antimicrobial assays, such as the minimum inhibitory concentration and microtitre plate biofilm forming assays, the inhibitory concentrations of Byotrol™ were found to range from 3 µg/mL to 15 µg/mL for planktonic cultures, and 3 µg/mL to 20 µg/mL for the biofilm growth of uropathogenic bacteria. Furthermore, the minimum biofilm eradication concentration assay demonstrated that 200-1000 µg/mL Byotrol™ was able to eradicate an established biofilm. Byotrol™ may also have significant potential as a device coating, as pre-coating data on glass slides and microtitre plates with the compound inhibited bacterial growth on the surface at concentrations of 400 µg/mL for E. coli, and 1000 µg/mL K. pneumoniae. Atomic force microscopy validated the expectation that higher concentrations of Byotrol™ coated a surface more evenly than lower concentrations. Using two-dimensional gel electrophoresis, the metabolic protein tryptophanase was seen to be significantly over-expressed when E. coli K12 was treated with sub-inhibitory concentrations of Byotrol™. A transcriptomic approach using RNA-Seq demonstrated that a majority of the differentially expressed genes were identified in cells that were challenged with 4 times the minimum inhibitory concentration of Byotrol™. Genes associated with protein synthesis and stress response were significantly up-regulated. Interestingly, the global gene regulators AI-2 and indole were significantly up-regulated, which may have an influence on the expression of genes related to motility, biofilm formation and acid-resistance. Genes associated with chemotaxis and motility, acid-resistance and iron transport were significantly down-regulated, particularly in cells challenged with Byotrol™.Byotrol™ displayed antimicrobial activity both in suspension and as a coating. Identification of differentially expressed genes and proteins, when the bacteria were treated and challenged with Byotrol™, has, for the first time, revealed the bacterial cell’s response to this biocide. The findings may enable the development of strategies to prevent or better manage catheter associated urinary tract infection (CAUTI).

The aim of the project of this doctoral thesis is the development of new synthetic strategies for the preparation of heterocyclic and heteropolycyclic compounds of potential interest in biological and pharmacological fields. In particular, we studied new general, flexible and regioselective synthetic approaches to oxygen and nitrogen heterocycles. We showed the versatility of nucleophilic addition/annulation domino reactions of alkyne compounds bearing a proximate nucleophile in the synthesis of heterocyclic systems, such as dihydroisobenzofurans, isoquinolines and naphthyridines. These approaches have been successfully transformed in Pd-catalysed multicomponent processes involving a one-pot coupling/addition/cyclisation sequence starting from the simple building blocks, such as ortho-bromoarylaldehydes, terminal alkynes and methanol or ammonia. In some cases, the reactivity of less reactive alkyne substrates has been enhanced by the catalysis of alkynophilic transition metals, such as gold and silver. In particular, we reported a new silver-catalysed approach to 2-methylisoquinolines and 5-methyl-1,6-naphtyridines by tandem addition/cyclisation of γ-ketoalkynes with ammonia. The domino approach has been also extended to 2-acetyl-N-propargylpyrroles for the synthesis of pyrrolo[1,2-a]pyrazine. In this case TiCl4 revealed to be the best promoter. Microwave heating demonstrated to be able to improve the efficiency of both domino and multicomponent processes. Finally, the project developed at the Institut für Organische und Biomolekulare Chemie in the Georg-August-Universität Göttingen (Germany), under the supervision of Prof. L. Ackermann, concerned with the direct arylations of indoles and pyrroles with differently substituted diaryliodonium salts in the absence of metal catalysts. The protocol proved broadly applicable, thereby enabling C-H bond functionalisations of free (NH)- as well as N-substituted indoles and pyrroles.

Phosphorous fertilizer has an efficiency of about 10 percent, and this efficiency must be improved, in order to avoid excessive loss of a non-renewable resource. Ammonium lignosulphonate (ALS), a by-product of the pulp and paper industry, is expected to improve efficiency of fertilizer phosphate (P) for corn (Zea mays L.) production. Field experiments were conducted to investigate effects of added ALS and P on soil organic matter and P fractions, as well as corn yields and nutrient uptake in a Ste. Rosalie clay soil and an Ormstown silty clay loam soil in 1990 and 1991. Incubation studies showed that added ALS increased organic matter but added P as diammonium phosphate (DAP) decreased organic matter in the fertilizer band location in both soils. Applied ALS with P increased Mehlich-III (M$ sb3$P) extractable P and bicarbonate extractable P in the fertilizer band location in both soils during early incubation periods. Soil Ca-P was decreased with increased ALS. However, soil Al-P and Fe-P compounds were increased with increased ALS. Applied P increased corn shoot P concentration at the six leaf stage, and increased grain yields, total dry matter (TDM) and N and P uptake in both soils. Applied ALS at up to 608 kg ha$ sp{-1}$ with P increased corn shoot P concentration at the six leaf stage in the Ste. Rosalie soil in 1991. Applied ALS at up to 304 kg ha$ sp{-1}$ with P increased grain yield, N and P uptake. However, applied ALS without P decreased stover N concentration. Thus, ALS may improve efficiency of fertilizer P for corn production depending on soil and application methods.

Chemistry
Ph.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

Accurate measurements of ammonia, nitric acid and formic acid are important for achieving a complete understanding of their atmospheric role. Models and measurements of formic acid in the atmosphere continue to show disagreements. Also, the contributions of NMHCs and reactive nitrogen (HNO3 and NH3) to organic and inorganic aerosol formation are important to quantify as gaps in the knowledge of atmospheric aerosols are a source of uncertainty in climate science. In this thesis, concentrations of ammonia were measured in the atmosphere and the production of formic acid from the ozonolysis of isoprene was measured in the EXTRA (EXTreme RAnge) chamber. Both gases were studied using chemical ionisation mass spectrometry (CIMS). The kinetics of the reactions of sesquiterpenes and terminal alkenes with ozone were studied in theEXTRA chamber using the relative rates technique and GC-FID. The ozonolysis rate coefficients of a homologous series of terminal alkenes were measured at elevated temperatures and found to be invariant with the carbon number. This led to the conclusion that previous measurements of these rate coefficients were subject to experimental artefacts. The elevated temperature protocol was employed to study the ozonolysis of sesquiterpenes, leading to revisions in ko3 for β-caryophyllene and α-humulene of 3 orders of magnitude. It was thus concluded that ozonolysis only accounts for 9-15% of sesquiterpeneoxidation in the atmosphere. A field intercomparison of CIMS for measuring ammonia was conducted wherein CIMS was found to perform well alongside instruments of comparable time response and limits of detection. This thesis also characterised inlet materials used in atmospheric measurements in the first systematic study on the uptake onto inlet walls in a flow tube system coupled to CIMS. It was found that PFA is the preferable material for atmospheric measurements, both for its kinetic qualities and its ready availability and ease of use. Finally, CIMS was used to measure the yield of formic acid from isoprene ozonolysis as a function of relative humidity. Formic acid yield was found to increase between 0-40% RH to a maximum of 0.18. Using the measured formic acid yields in a global chemistry model leads to an estimate that formic acid production from isoprene ozonolysis is ~9.5 Tg yr-1.

Esta tesis doctoral versa sobre la eliminación simultánea de compuestos fenólicos con reactores de biomasa granular trabajando en continuo. El estudio está dividido en dos partes principales; el primer tema trata sobre la modelización de la nitritación, mientras que el otro está dedicado al trabajo experimental sobre la nitritación y eliminación simultánea de compuestos fenólicos. En el estudio de modelización, se desarrolló un modelo matemático de biopelícula para describir la nitritación en reactores de biomasa granular aerobia operando en continuo. El modelo incorpora una estrategia de control del ratio [DO]/[TAN], para mantener un valor deseado de la relación entre las concentraciones de oxígeno disuelto (DO) en el efluente del reactor y nitrógeno amoniacal total [TAN]. El modelo se validó con un gran número de datos experimentales previamente publicados en la bibliografía, así como con datos obtenidos de reactores granulares tratando agua de rechazo a escala laboratorio y piloto. El modelo se utilizó para estudiar el efecto de: a) las consignas de DO y TAN, b) la temperatura de operación, c) las características de la biopelícula (tamaño de partícula, densidad) y d) la concentración de amonio en el afluente, sobre la consecución de la nitritación completa. Los resultados indicaron que la nitritación completa se mantuvo estable y se potenció usando la estrategia de control de la proporción [DO]/[TAN] en la operación del reactor de biomasa granular aerobia. Además, el modelo predijo que gránulos aerobios mayores a 1.5 mm y concentraciones altas de amonio en el afluente potenciaba la obtención de nitritación completa estable, mientras que la densidad de biopelículas tenía poca influencia en este estudio. Además se demostró que era posible la nitritación total a bajas temperaturas con reactores de biomasa granular. Para el trabajo experimental, se utilizó un reactor tipo airlift. Para la puesta en marcha del reactor, se utilizó como inóculo biomasa de un reactor de biomasa granular aerobia que realizaba eliminación de nutrientes. Como alimento del reactor se utilizó un agua residual sintética con un alto contenido de amonio (950 ± 25 mg N L-1). El reactor se operó hasta la obtención de nitritación parcial. Una vez obtenida la nitritación parcial, el reactor se bioaumentó con un lodo activo que contenía biomasa degradadora de p-nitrofenol (PNP) para mejorar el crecimiento de microorganismos degradadores de fenol sobre los gránulos nitrificantes. Acto seguido, mientras el reactor trataba una carga elevada de amonio, se añadieron progresivamente al afluente o-cresol (hasta 100 mg L-1) o PNP (hasta 15 mg L-1), siendo éstos alimentados al reactor con el objetivo de estudiar la nitritación parcial simultánea a la eliminación de o-cresol o de PNP. En el estudio de la nitritación parcial simultánea a la eliminación de o-cresol, se mantuvo el proceso de nitritación parcial estable durante más de 100 días de operación. Además, se obtuvo una biodegradación completa de o-cresol durante todo el periodo experimental. También se realizaron choques de carga de o-cresol, durante los cuales el proceso de nitritación parcial se mantuvo estable y sin verse afectado por esos eventos. Las cargas volumétricas obtenidas de nitrógeno (NLRV) y de o-cresol (CLRV) fueron de 1.1 g N L-1 d-1 y 0.11 g o-cresol L-1 d-1, respectivamente. El análisis de hibridación in situ de fluorescencia (FISH) indicó que en los gránulos había presencia del género Acinetobacter, de bacterias amonio-oxidantes betaproteobacteriales y de Nitrobacter sp. Posteriormente, se continuó con la operación del reactor, y se llevó a cabo un experimento relacionado con el funcionamiento del reactor bajo tres escenarios de alternancia secuencial de contaminantes (SAP). En cada uno de los escenarios SAP se añadieron 15 mg L-1 de compuestos fenólicos secundarios (i.e. PNP, fenol y 2-clorofenol (2CP)) al afluente por un periodo de tiempo corto (entre 20 y 25 años). Los resultados ilustraron que se mantuvo la nitritación parcial y la biodegradación de o-cresol sin mostrar ningún signo de inhibición por la presencia de PNP o de fenol. Sin embargo, en presencia de 2CP en el afluente, se registró durante tres días un 90% de la nitritación parcial y un 25% de la degradación de o-cresol. Estos resultados sugieren que las bacterias amonio oxidantes (AOB) son mas sensibles a la inhibición por 2CP que las heterótrofas (degradadoras de o-cresol). En el estudio de la nitritación simultánea a la eliminación de PNP, se mantuvo la nitritación durante la mayor parte del periodo operacional, obteniéndose un efluente adecuado para la desnitrificación heterotrófica. Sin embargo, durante los primeros 175 días, la biodegradación de PNP fue inestable, observándose diversos episodios de acumulación de PNP. Esta acumulación se determinó que era debida a las condiciones limitantes de DO. El incremento de la concentración de DO en el reactor de 2 a 4 mg O2 L-1 permitió obtener eliminación completa y estable de PNP hasta el fin del periodo experimental. Las NLRV y la carga de PNP obtenidas fueron de 1.0 g N L-1 d-1 y 16 mg PNP L-1 d-1, respectivamente. Además, se evaluó el funcionamiento del reactor realizando dos estudios de hambruna, i) hambruna de PNP y ii) hambruna total (parada del reactor). Los resultados mostraron que 2 días después al fin del periodo de hambruna se obtuvo una recuperación total de la degradación de PNP, mientas que la recuperación total de la nitritación simultánea a la eliminación de PNP se consiguió solo 11 después de volver a poner en marcha el reactor. En conclusión, el uso de reactores de biomasa granular aerobia para realizar nitritación simultánea a la eliminación de compuestos fenólicos es factible. Ésta podría ser considerada la mejor técnica disponible para el tratamiento aguas residuales industriales complejas con contenido de amonio en alta carga y compuestos fenólicos. Se ha probado que la biomasa granular aerobia es resistente a sobrecargas puntuales, a presencia alterna de compuestos recalcitrantes y a periodos de hambruna; estas condiciones, debido a los cambios de planificación de la producción, pueden encontrarse frecuentemente en plantas de tratamiento de aguas residuales industriales. En un futuro próximo, proponemos que la nitritación simultánea a la eliminación de compuestos fenólicos podría combinarse tanto con la desnitrificación heterotrófica o con el proceso anammox para una eliminación sostenible del nitrógeno.
The simultaneous nitritation and phenolic compounds removal using aerobic granular reactors in continuous mode were studied in this Ph.D. thesis. The study is divided into two main subjects; the first one is devoted to the modeling of nitritation while the other part is dedicated to the experimental work of simultaneous nitritation and phenolic compounds removal using granular reactors. In the modeling study, a mathematical biofilm model was developed to describe nitritation in aerobic granular reactors operating in continuous mode. The model incorporated a [DO]/[TAN] ratio control strategy to maintain the proportion between the concentrations of dissolved oxygen (DO) and total ammonia nitrogen (TAN) in the reactor effluent to a desired value. The model was validated with a large set of experimental results previously reported in the literature, as well as, data gathered from laboratory scale and pilot plant granular reactors treating reject water. The model was used to study the effect of: a) DO and TAN setpoints, b) operating temperature, c) biofilm characteristics (granules size, density) and d) ammonium concentrations in the influent on the achievement of full nitritation. The results indicated that full nitritation was stably maintained and enhanced by applying the [DO]/[TAN] ratio control strategy in the operation of aerobic granular sludge reactor. Moreover, the model predicted that aerobic granules size larger than 1.5 mm and high ammonium concentrations in the influent enhanced the achievement of stable full nitritation, while poor influence of the biofilm density was found with the simulation study. Furthermore, at low temperature, full nitritation with granular reactors was demonstrated to be possible. In the experimental work, an airlift reactor was employed. In the reactor start-up, granular sludge from a reactor performing biological nutrient removal was used as inoculum. A synthetic wastewater containing high-strength ammonium concentrations (950 ± 25 mg N L- 1) was fed into the airlift reactor. The reactor was operated until partial nitritation was obtained. Once partial nitritation was achieved, the airlift reactor was bioaugmented with pnitrophenol (PNP)-degrading activated sludge to enhance the growth of phenolic-degraders over the nitrifying granules. Immediately, o-cresol (up to 100 mg L-1) or PNP (up to 15 mg L- 1) were progressively added to the high-strength ammonium influent and fed into the reactor with the objective of studying the simultaneous partial nitritation and o-cresol removal and the simultaneous nitritation and (PNP) removal. First, in the study of simultaneous partial nitritation and o-cresol removal, a stably partial nitritation process was maintained for more than 100 days of operation. Moreover, full biodegradation of o-cresol was achieved during the whole experimental period. Also, o-cresol shock load events were applied and the partial nitritation process was kept stable and unaffected during these events. The achievable nitrogen loading rate (NLRv) and o-cresol loading rate (CLRv) were ca. 1.1 g N L-1d-1 and 0.11 g o-cresol L-1d-1, respectively. Analysis of fluorescent in-situ hybridization (FISH) indicated that Acinetobacter genus, betaproteobacterial ammonia-oxidizing bacteria and Nitrobacter sp. were present into the granules. Later, the operation of the reactor was continued, and an experiment devoted to the performance of the reactor under three sequentially alternating pollutant (SAP) scenarios was executed. In each one of the SAP scenarios, 15 mg L-1 of the secondary phenolic compounds (i.e. p-nitrophenol (PNP), phenol and 2-chlorophenol (2CP)) were added in the regular influent for a short period of time (between 20 to 25 days). The results illustrated that partial nitritation and o-cresol biodegradation were maintained without exhibiting any sign of inhibition by the presence of PNP or phenol. However, when 2CP was present in the influent, 90 % of the partial nitritation and 25 % of the o-cresol degradation was inhibited within three days. This finding suggests that the ammonia oxidizing bacteria (AOB) is more sensitive to 2CP inhibition than heterotrophs (o-cresol-degraders). Second, in the study of simultaneous nitritation and PNP removal, nitritation was maintained during most of the operation period producing an effluent suitable for heterotrophic denitrification. However, in the first 175 days, PNP biodegradation was unstable and several accumulation episodes occurred. The oxygen limiting condition was found to be the main explanation of these events. The increase of dissolved oxygen concentration (DO) in the reactor from 2 to 4 mg O2 L-1 permitted to achieve complete and stable PNP removal till the end of the experimental period. The achieved NLRv and PNP loading rate (PNP-LRv) were ca. 1.0 g N L-1d-1 and 16 mg PNP L-1d-1, respectively. Besides, the performance of the reactor was further assessed by performing two starvation studies, i) PNP starvation and ii) total starvation period (reactor shutdown). Results show that full recovery of PNP degradation was achieved within 2 days after the PNP starvation period ended, while full recovery of simultaneous nitritation and PNP removal was accomplished in just 11 days after the restart of the reactor. In conclusion, the use of continuous aerobic granular reactors for the simultaneous nitritation and phenolic compounds removal is feasible. This could be regarded as a best available technique for the treatment of complex industrial wastewaters containing high-strength ammonium concentrations and phenolic compounds. Aerobic granules are proven to be resistant and resilient to the shock loads, to the alternating presence of recalcitrant compounds and to starvation periods; conditions frequently found in industrial wastewater treatment plants due to changes on the industrial production schedules. In the near future, we propose the simultaneous nitritation and phenolic compounds removal should be combined with either heterotrophic denitrification or Anammox for sustainable nitrogen removal.

We have described herein a convenient one-pot synthesis of lisulfides/diselenides from a-amino acids mediated by ammonium etrathiomolybdate in water. (Figure 1) (Figure) Figure 1 Transformation of α-amino acids into the corresponding tiiocyanates/selenocyanates/disulfides/diselenides Halo-de-amination of a-amino acids using HBr/NaNCte followed by treatment with ammonium tetrathiomolybdate (NH4)2]VloS4 jLb provided a general route for the the one-pot synthesis of chiral a,a' bis (dithio) carboxylic acids (Figure 1, 2b). The yields were moderate, limited mainly the moderate conversion of a-amino acids into the corresponding chiral a-bromides. It was possible to synthesize the 2-thiocyanto carboxylic acids from the corresponding a-amino acids by a similar strategy. Thus diazotization in the presence of KSCN yielded in the chiral 2-thiocyanto carboxylic acids in moderate yields (Figure 1, 3). Thiocyanato-de-amination thus afforded the thiocyanates which when treated with JJD provided the chiral disulfides (Figure 1, 4a). We could thus synthesize both enantiomers of the disulfide from a single enantiomer of the starting a-amino acid. (Figure 1, 4a,4b) Using a similar strategy we have also demonstrated an efficient method for the synthesis of chiral selenocyanates starting from a-amino acids, using selenocyanate anion as the nucleophile (Figure 1, 5). It is possible to demonstrate a one-pot synthesis of chiral diselenides by reductive coupling of selenocyanates using JJb. (Figure 1, 6) (for figure see the pdf file)

We have described herein a convenient one-pot synthesis of lisulfides/diselenides from a-amino acids mediated by ammonium etrathiomolybdate in water. (Figure 1) (Figure) Figure 1 Transformation of α-amino acids into the corresponding tiiocyanates/selenocyanates/disulfides/diselenides Halo-de-amination of a-amino acids using HBr/NaNCte followed by treatment with ammonium tetrathiomolybdate (NH4)2]VloS4 jLb provided a general route for the the one-pot synthesis of chiral a,a' bis (dithio) carboxylic acids (Figure 1, 2b). The yields were moderate, limited mainly the moderate conversion of a-amino acids into the corresponding chiral a-bromides. It was possible to synthesize the 2-thiocyanto carboxylic acids from the corresponding a-amino acids by a similar strategy. Thus diazotization in the presence of KSCN yielded in the chiral 2-thiocyanto carboxylic acids in moderate yields (Figure 1, 3). Thiocyanato-de-amination thus afforded the thiocyanates which when treated with JJD provided the chiral disulfides (Figure 1, 4a). We could thus synthesize both enantiomers of the disulfide from a single enantiomer of the starting a-amino acid. (Figure 1, 4a,4b) Using a similar strategy we have also demonstrated an efficient method for the synthesis of chiral selenocyanates starting from a-amino acids, using selenocyanate anion as the nucleophile (Figure 1, 5). It is possible to demonstrate a one-pot synthesis of chiral diselenides by reductive coupling of selenocyanates using JJb. (Figure 1, 6) (for figure see the pdf file)

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.

Fertilizer P fixation and fertilizer N losses in soils may be reduced through additions of polyphenolic compounds. The influence of ammonium lignosulfonate (NH$ sb4 sp+$-LS) on triple superphosphate (TSP) efficiency was investigated in a soil incubation study using three Quebec soils and in a growth bench study using one soil. For the incubation study, soils were analyzed for pH and P extractability, as a function of NH$ sb4 sp+$-LS rate and time. In the growth bench study, TSP and NH$ sb4 sp+$-LS were applied at varying rates and corn (Zea mays L.) dry matter yields and nutrient compositions analyzed. Similar studies were conducted in subsequent growth bench studies, to evaluate combinations of NH$ sb4 sp+$-LS, diammonium phosphate (DAP), and urea on two soils.
Ammonium LS increased soluble P levels when applied with TSP. The effect was most significant in fine textured soils, and increased with time. This improved P availability to plants, without affecting growth. The optimum NH$ sb4 sp+$-LS:P$ sb2$O$ sb5$ application ratio was approximately 2.8:1. Ammonium LS did not improve availability of DAP-P in either of the subsequent experiments, nor did it improve urea fertilizer efficiency. Some NH$ sb4 sp+$-LS-urea-DAP formulations did, however, improve corn growth beyond that obtained when only urea and DAP were applied in combination. In nutrient amended soils, applying NH$ sb4 sp+$-LS DAP was detrimental to growth and, for some application rates, reduced nutrient uptake.

Master of Science
Food 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.

Cette thèse décrit la Chimie Covalente Dynamique (CCD) des échanges imine/imine, Knoevenagel/imine et Knoevenagel/Knoevenagel. La L-proline est un excellent organocatalyseur pour la formation de Bibliothèques Covalentes Dynamiques (BCDs). Cependant, l’interconversion entre des dérivées Knoevenagel de l’acide diméthylbarbiturique et des imines se déroule rapidement sans catalyseur. Une nouvelle classe de CCD basée sur des échanges par substitutions nucléophiles (SN2/SN2’) entre des sels d’ammonium quaternaires et des amines tertiaires est développée, impliquant la catalyse par l’iodure. Les réactions d’échange entre des sels de pyridinium et un dérivé de pyridine génèrent des liquides ioniques dynamiques. Enfin, la sélection cinétique et thermodynamique de la formation d’imines dans la CCD est réalisée en solution aqueuse e ten solvant organique
This thesis describes the dynamic covalent chemistry (DCC) of imine/imine, Knoevenagel/imine, and Knoevenagel/Knoevenagel exchange. L-proline is shown to be an excellent organocatalyst to accelerate the formation of dynamic covalent libraries (DCLs). The interconversion between Knoevenagel derivatives of dimethylbarbituric acid and imines is found to occur rapidly in the absence of catalyst. A new class of DCC based on nucleophilic substitution (SN2/SN2’) component exchange between quaternary ammonium salts and tertiary amines is developed, by the use of iodide as a catalyst. The exchange reactions between pyridinium salts and a pyridine derivative generate dynamic ionic liquids. Finally, kinetic and thermodynamic selection of imine formation in a DCC is perfomed in aqueous solution and organic solvent

The objective of the present work was systematic investigation of water-based headspace single-drop microextraction (SDME) technique, its conjunction with capillary electrophoresis, and application for the analysis of volatile inorganic compounds (cyanide and ammonium) in biomedical and environmental samples. Theoretically evaluated and experimentally confirmed that the manipulation in the volatility of the analyte by its chemical modification in the sample and/or in the acceptor phase is the most effective way to enhance the extraction performance in headspace SDME. Maximum extraction efficiency for cyanide was observed in the pH range 4.5–7.5, where cyanide anion is completely transferred into volatile HCN. Complete cyanide recoveries (≥96%) from metal-cyanide complexes were obtained by using two ligand-exchange reagents (ethylenediamine and dithizone). Maximum extraction efficiency was observed by the extraction of ammonia from alkaline samples (pH≥11) with neutral or slightly acidic acceptor phase (pH 3-7). Compared to existing methods water-based headspace SDME is significantly faster and simpler. In addition, proposed technique does not require any sample pre-treatment (deproteinization, acidic/alkaline distillation, etc.) and thus is much less susceptible to interferences. Finally, it offers possibility to choice of a wider variety of solvents and, consequently, enhances the range of extractable analytes as well as the range of analytical methods that can be coupled... [to full text]
Daktaro disertacijoje nuodugniai ištirtas mikroekstrakcijos iš viršerdvės vandens lašu metodas, apjungtas su kapiliarine elektroforeze bei pritaikytas lakių neorganinių junginių (cianido ir amonio) koncentravimui ir nustatymui biomedicininiuose ir aplinkos objektuose. Teoriniais skaičiavimais parodyta ir eksperimentiškai patvirtinta, kad efektyviausias būdas mikroekstrakcijos iš viršerdvės efektyvumui pagerinti – analitės lakumo didinimas chemiškai modifikuojant ją prieš ekstrakciją ir/arba jos lakumo mažinimas modifikuojant ją akceptorinėje fazėje. Maksimalus cianido mikroekstrakcijos efektyvumas pasiekiamas pH srityje 4,5- 7,5, kur cianidas kiekybiškai pervedamas į lakų HCN. Ištyrus cianido mikroekstrakciją tirpiklio lašu iš metalų cianidinių kompleksų tirpalų nustatyta, kad kiekybiškas silpnai surišto cianido suardymas (cianido išgavos siekia ≥96%) pasiekiamas panaudojus ligandų mainus etilendiamino ir ditizono mišiniu. Maksimalus amonio mikroekstrakcijos efektyvumas pasiekiamas ekstrahuojant jį iš pašarmintų mėginių (pH≥11) akceptorine faze, kurios pH 3-7. Lyginant su standartiniais metodais, siūlomas metodas yra greitesnis ir paprastesnis, visiškai eliminuojama mėginio matricos įtaka, nereikalingos jokios drastiškos (deproteinizacija, veikimas rūgštimis/šarmais, distiliacija ir pan.) manipuliacijos su mėginiu, todėl išvengiama mėginio matricos įtakos. Mikroekstrakcija iš viršerdvės vandens lašu praplečia mikroekstrakcijos metodų taikymo sritis: atveriama galimybė labai... [toliau žr. visą tekstą]

Elaboration d'une nouvelle technique qui associe un agent original de bromation (le tribomure de tetrabutylammonium) a un dosage voltamperometrique. Cette nouvelle technique permet non seulement de determiner un indice de brome dans le cas des fractions lourdes des petroles, mais encore pour la premiere fois d'effectuer une discremination entre reaction d'addition et reaction de substitution

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.

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.

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.

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]