Thesis (Ph. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

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Ce travail de thèse concerne la formulation et la mise en œuvre d'un ensimage thermoplastique, respectueux de l'environnement et utilisable à une échelle industrielle. La première étape du projet a été d'adapter les moyens et les ingrédients de formulation aux contraintes industrielles. La formule d'ensimage est basée sur une dispersion aqueuse de particules de polymère thermoplastique (PEI) obtenue par la technique d'émulsion/évaporation. Le choix de la technique de dispersion et du solvant volatil ont été les premières modifications apportées à la formulation d'ensimage qui existait à l'échelle laboratoire. Une optimisation de la dispersion aqueuse a été nécessaire pour répondre aux contraintes industrielles de stabilité, de température et de mise en œuvre. La seconde étape a été l'optimisation de la dispersion aqueuse d'ensimage par une modélisation prédictive puis sa validation expérimentale. L'étude prédictive (QSPR) a permis de se focaliser sur deux paramètres essentiels influençant la stabilité de la dispersion : la vitesse d'émulsification et la concentration en tensioactif. La validation expérimentale nous a permis de confirmer l'importance de ces paramètres et ainsi mieux maîtriser l'élaboration des dispersions. Afin de répondre aux exigences industrielles, notamment en termes de comportement rhéologique, une nouvelle formule d'ensimage a été élaborée. Cette dernière met à profit le comportement viscoélastique de tubules formés par l'association CTAC/acide salicylique, pour préparer des dispersions aqueuses stables. Il s'agit là du premier exemple d'utilisation de tubules pour disperser dans l'eau des particules de polymère par la technique d'émulsion/évaporation. La stabilité de la dispersion a été mesurée à 22h et les propriétés de la dispersion permettent une redispersion aisée de la formulation même après déstabilisation. Enfin cette dispersion d'ensimage a fait l'objet de tests laboratoires et pilotes pour réaliser, respectivement, un film sur plaques de graphite et un ensimage sur fibres de carbone HexTow(r) IM7 sur la chaîne d'ensimage de notre partenaire industriel. Les résultats ont montré un ensimage abondant et qui montrait de bonnes propriétés d'adhésion dans le matériau composite final. Cette dispersion d'ensimage a été brevetée par Airbus Defence & Space. / This PhD project is related to the development of an eco-friendly thermoplastic sizing formulation and its implementation as sizing, usable at an industrial scale. The first step of the project was to adjust the preparation and the ingredients of this formulation to the industrial requirements. The sizing formulation is based on an aqueous dispersion of thermoplastic polymer particles (PEI) obtained by an emulsion/solvent evaporation process. The choice of the dispersion method and the volatile solvent were the first modifications achieved on the sizing formulation which was available at a laboratory scale. An optimization of the aqueous dispersion was necessary to meet the industrial requirements of stability, temperature and implementation. The second step was the optimization of the aqueous sizing dispersion by a predictive model, and then its experimental validation. The predictive study (QSPR) permitted to focus on two essential parameters affecting the stability of the dispersion: the stirring speed and the surfactant concentration. The experimental validation permitted to confirm the importance of these parameters and consequently a better understanding of the dispersion process. In order to satisfy the industrial requirements, especially in terms of rheological behavior, a new sizing formulation was elaborated. This latter takes advantage of the visco-elastic behavior of the tubules formed by the association CTAC / salicylic acid, to formulate stable aqueous dispersions. This is the first example of use of tubules to disperse polymer particles in water by emulsion/solvent evaporation process. The stability of dispersion was measured to 22 hours and the proprieties of this dispersion permit an easy redispersion of formulation even after destabilization. Finally, this sizing dispersion was tested in laboratory and industry to make, respectively, film on carbon slab and sizing on carbon fibers HexTow(r) IM7 using industrial sizing means. The results showed an abundant sizing and good adhesion properties in the final composite material. This sizing dispersion was patented by Airbus Defence & Space.

The Keap1-Nrf2 pathway is a major upstream regulator of xenobiotic detoxification. In Drosophila, directed activation of the protein complex of Keap1 and CncC (the homolog of human Nrf2) in principal and stellate cells of the Malpighian (renal) tubules confers resistance to lethal doses of the pesticide malathion, which is metabolized into organic anions. Dietary exposure to organic anions such as salicylate (10 mM) causes increases in fluid secretion rate and salicylate flux across Malpighian (renal) tubules. Here we used salicylate-selective microelectrodes and Ramsay assays to determine the role of Keap1/CncC in regulating these responses. Fluid secretion rate and salicylate flux across tubules isolated from adults with directed activation of Keap1/CncC in the principal cells are comparable to the values from salicylate-fed controls. Fluid secretion rate, concentration of salicylate in the secreted fluid and salicylate flux did not differ significantly between tubules isolated from adults with directed activation of Keap1/CncC in the principal cells reared on a diet containing salicylate and those reared on control media, indicating that the detoxification pathway was activated regardless of the presence of dietary salicylate. This is in contrast to the significant increase in fluid secretion rate and salicylate flux between tubules isolated from salicylate-fed adults and adults reared on a control diet with directed activation of Keap1/CncC in the stellate cells, supporting previous studies that demonstrated the inability of stellate cells to transport organic anions. Taken together, these results suggest a role for Keap1/CncC in upregulating fluid secretion in response to the presence of dietary organic anions. / Thesis / Master of Science (MSc) / The Keap1-Nrf2 pathway is a major upstream regulator of xenobiotic detoxification. In Drosophila, directed activation of the protein complex of Keap1 and CncC (the Nrf2 homolog) in principal and stellate cells of the Malpighian (renal) tubules confers resistance to lethal doses of the pesticide malathion, which is metabolized into organic anions. Dietary exposure to organic anions such as salicylate (10 mM) causes increases in fluid secretion rate and salicylate flux across Malpighian (renal) tubules that are comparable to tubules isolated from adults with activated Keap1/CncC reared on a salicylate-free diet. This suggests a role for Keap1/CncC in upregulating fluid secretion in response to the presence of dietary organic anions.

Thesis (Ph. D.)--University of Texas Health Science Center at Houston, School of Public Health, 2007. / Source: Dissertation Abstracts International, Volume: 68-12, Section: B, page: 7975. Adviser: Mary Ann Smith. Includes bibliographical references.

Haloalkenes were shown to react with cysteine, N-acetyl cysteine, or glutathione to form halogenated vinylthio (HVT) or saturated conjugates. When HVT were administered iv to rabbits, active transport in the renal tubules was inhibited 50% at doses as low as 20 mg/kg within 1 hr after dosing. There was sloughing of the renal brush border membrane with the injury progressing to a specific renal tubular necrosis of the S₃ segment. In vitro studies with renal tubules found that the HVT produced a dose-response related inhibition of acid/base transport, with complete inhibition of transport occurring at 1 mM. The cysteine conjugate synthesized from trichloroethylene, DCVC, inhibited tubular active transport 60 min after in vivo dosing (20-100 mg/kg), 45 min after exposure in the isolated perfused kidney (0.01-1 mM) and 15 min after incubation with isolated tubules (0.01-1 mM). All HVT conjugates had a similar potency with regard to transport inhibition in isolated tubules, with complete inhibition occurring at 1 mM within 15 min for cysteine conjugates compared to 45-60 min for the N-acetyl cysteine or glutathione conjugates. These latter conjugates are thought to be bioactivated to the cysteine conjugate prior to transport inhibition. Inhibition of tubular (gamma)-glutamyl transpeptidase by 1 mM AT-125 or 20 mM serine/borate prevented the inhibition of acid/base transport by the glutathione conjugate. In addition, the sequential formation of glutamate, glycine and the vinyl cysteine conjugate after tubule incubation with the glutathione conjugate provides further evidence for this bioactivation. The cysteine conjugates are thought to be further metabolized in tubules to a toxic intermediate by a brush border localized enzyme, C-S lyase. The inhibitor effect of this intermediate on acid/base transport is reversed in the presence of, or subsequent addition of, 6 mM exogenous glutathione. These studies provide further evidence for the nephrotoxicity of HVT, and formation of the nephrotoxic cysteine conjugates from glutathione and cysteine conjugates. The formation of saturated conjugates from CTFE was also demonstrated. These saturated and/or unsaturated conjugates may be responsible for haloalkene-induced nephrotoxicity.

The purpose of this study was to compare the antimicrobial effect of MTAD, two of its components, doxycycline and citric acid, and NaOCl on E. faecalis in two in vitro models: the bovine tooth model and the agar diffusion model. In the tooth model, the lumens of thirty bovine dentin discs were standardized, autoclaved and infected with E. faecalis for 14 days. The infected dentin discs were treated with either MTAD, doxycycline 100mg/ml, 10% citric acid, 5.25% NaOCl or saline for 10 minutes. Dentinal shavings were collected using sterile 037 and 040 round burs. The number of bacteria in the shavings was enumerated by overnight CO2 culturing on TSA agar plates. For the agar diffusion model, E. faecalis was plated before placing paper discs wetted with three dilutions of each irrigant. The zone of inhibition was recorded after overnight culture. The data were analyzed with a two-way ANOVA and Tukey-Kramer post-hoc test. In the bovine tooth model, NaOCl and doxycycline were more effective than control in killing E. faecalis at the shallow bur depth but at the deeper bur depth, only NaOCl was significantly more effective (psE. faecalis.

Wang Jian Bin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 117-131). / ACKNOWLEDGEMENTS --- p.ii / ABSTRACT --- p.x / Chapter PART I. --- GENERAL INTRODUCTION --- p.4 / Chapter PART II. --- LITERATURE REVIEW --- p.6 / Chapter A. --- The structure and functions of insect Malpighian tubules --- p.6 / Chapter I. --- The excretory system of insects --- p.6 / Chapter 1. --- Morphology of Malpighian tubules --- p.6 / Chapter 2. --- Common types of Malpighian tubule system --- p.7 / Chapter 3. --- Morphology of hindgut --- p.8 / Chapter II. --- Structure of insect Malpighian tubules --- p.9 / Chapter 1. --- General organization of the Malpighian tubules --- p.9 / Chapter 2. --- Structure of the principal cell --- p.10 / Chapter 3. --- The structure of other cell types --- p.14 / Chapter 4. --- The cryptonephridial systems in larvae of Lepidoptera and Coleoptera --- p.16 / Chapter III. --- Functions of insect Malpighian tubules --- p.18 / Chapter 1. --- Mechanism of fluid secretion by Malpighian tubules --- p.18 / Chapter 1.1. --- Ion transport --- p.18 / Chapter 1.2. --- Fluid transport --- p.19 / Chapter 2. --- Active transport of organic compounds by Malpighian tubules --- p.19 / Chapter 2.1. --- Organic anions --- p.19 / Chapter 2.2. --- Organic cations --- p.20 / Chapter 3. --- Resporptive processes in Malpighian tubules --- p.20 / Chapter 3.1. --- KC1 resorption --- p.20 / Chapter 3.2. --- Reabsorption of sugars --- p.21 / Chapter 4. --- The passive permeability of Malpighian tubules --- p.21 / Chapter B. --- The biology and mode of action of Bacillus thuringiensis --- p.23 / Chapter I. --- Introduction --- p.23 / Chapter II. --- Background --- p.23 / Chapter III. --- "Cytology of germination, outgrowth and sporulation" --- p.24 / Chapter IV. --- Bacillus thuringiensis and its toxins --- p.26 / Chapter V. --- Histopathological effects of Bacillus thuringiensis δ-endotoxin on Lepidopterous larva --- p.29 / Chapter VI. --- Mode of action of Bacillus thuringiensis δ-endotoxin --- p.32 / Chapter C. --- The biology and pathological effects of microsporidian protozoa --- p.36 / Chapter I. --- Life cycle of microsporidian protozoa --- p.36 / Chapter II. --- Germination of microsporidian protozoa --- p.37 / Chapter III. --- The fine structure of microsporidian protozoa --- p.38 / Chapter IV. --- Mass production and storage --- p.42 / Chapter V. --- Pathology of microsporidian protozoa --- p.44 / Chapter PART III. --- LIGHT AND ELECTRON MICROSCOPIC STUDIES OF THE MALPIGHIAN TUBULES OF PIERIS CANIDIA LARVA (LEPIDOPTERA) --- p.48 / Summary --- p.48 / Introduction --- p.48 / Materials and methods --- p.49 / Results --- p.50 / Discussion --- p.53 / Chapter PART IV. --- HISTOCHEMICAL STUDIES ON THE PIERIS CANIDIA LARVAL MALPIGHIAN TUBULES --- p.58 / Summary --- p.58 / Introduction --- p.59 / Materials and methods --- p.60 / Results --- p.52 / Discussion --- p.66 / Chapter PART V. --- SEPARATION AND PURIFICATION OF PARASPORAL CRYSTALS OF BACILLUS THURINGIENSIS VAR. KURSTAKI --- p.70 / Summary --- p.70 / Introduction --- p.70 / Materials and methods --- p.74 / Results --- p.77 / Discussion --- p.77 / Chapter PART VI. --- HISTOPATHOLOGICAL EFFECTS OF BACILLUS THURINGIENSIS VAR. KURSTAKI δ-ENDOTOXIN ON THE MALPIGHIAN TUBULES OF PIERIS CANIDIA LARVA --- p.79 / Summary --- p.79 / Introduction --- p.79 / Materials and methods --- p.81 / Results --- p.83 / Discussion --- p.86 / Chapter PART VII. --- THE FINE STRUCTURE OF A MICROSPORIDIAN NOSEMA POLYVORA FROM CABBAGE WHITE PIERIS CANIDIA --- p.92 / Summary --- p.92 / Introduction --- p.92 / Materials and methods --- p.94 / Results --- p.94 / Discussion --- p.97 / Chapter PART VIII. --- HISTOPATHOLOGICAL EFFECTS OF NOSEMA POLYVORA ON THE MALPIGHIAN TUBULES OF PIERIS CANIDIA LARVA --- p.103 / Summary --- p.103 / Introduction --- p.103 / Materials and methods --- p.105 / Results --- p.105 / Discussion --- p.107 / Chapter PART IX. --- GENERAL DISCUSSION --- p.111 / Chapter PART X. --- CONCLUSION AND SUMMARY --- p.115 / REFERENCES --- p.117 / FIGURES AND TABLES --- p.132

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 166-185). Also available in print.

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains viii, 135 p. : ill. Vita. Includes abstract. Includes bibliographical references.