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Malachite green(MG), an N-methylated diaminotriphenylmethane dye, has been widely used as an antifungal agent in aquaculture. Malachite green is reduced to and persists as leucomalachite green(LMG) in the tisssues of fish. Concern over MG and LMG are due to the potential for consumer exposure, suggestive evidence of tumor promotion in rodent liver, and suspicion of carcinogenicity based on structure-activity relationships. Several hepatotxicants and liver carcinogens have been shown to alter cell-cell signaling by interference with gap junction intercellular communication (GJIC).This study wanted to determine if disruption of cell-cell interactions occurs in rat liver epithelial cells in response to MG and LMG treatment. Rat liver epithelial cells(WB) were treated with LMG(0~6£gg/ml) or MG.(0~5£gg/ml) for one hour and gap junction was analyzed using the scrape- loading/dye transfer assay. The viability and proliferation of rat liver epithelial cells treated with LMG or MG were determined by MTT and colony forming efficiency. In addition, expression and intracellular localization of connexin43, E-cadherin,£]-catenin,£\-tubulin, ZO-1 and occludin were determined by immunoblot and immunostain analysis. A clear decrease in the distance of dye transfer was evident following treatment with MG(0~5£gg/ml) or LMG(0~6£gg/ml). Treatment with LMG and MG at different concentrations resulted in a decrease in cell viability and cell proliferation. Preincubation of cells with protein kinase C(PKC) inhibitor decreased the inhibition of GJIC by 5ug/ml MG and the specific MEK 1 inhibitor decreased substantially the inhibition of GJIC by 5£gg/ml MG and 5£gg/ml LMG. On the other hand, the specific PI3 kinase inhibitor decreased the inhibition of GJIC only by 3£g/mlLMG and we treated WB cells with EDTA to chelate extracellular calcium ion. The decrease of free calcium ion caused the expression of GJIC. At the transcriptional level, 10£gg/ml LMG and 10£gg/ml MG after treatment for one hour caused no change in the level of connexin43 mRNA. At the translational level, the different concentrations of MG or LMG after treatment for one hour or 24 hours caused a decrease in the level of the concentrations of connexin43 protein, E-cadherin protein,£]-catenin protein,£\-tubulin protein, ZO-1 protein and changed the distribution of occludin and ZO-1. Therefore, these data speculated the hypothesis that disruption of cell-cell signaling by interference with GJIC may contribute to LMG and MG toxicity, carcinogenicity and apoptosis.

The malachite green aptamer was originally engineered for binding specificity to malachite green (MG). The environment inside the aptamer’s electronegative binding pocket was previously harnessed to catalyze an ester cleavage via the stabilization of positively charged intermediates. In order to further explore and expand the catalytic potential of this molecule we have analyzed the binding and chemical properties of MG derivatives. The catalyzed reaction rate is approximately 2000-fold faster than the non-catalyzed reaction rate. This catalytic activity demonstrates the possible significance of electrostatic forces in RNA enzymes. The ability of RNA to catalyze different reactions depending on the substrate provided would have been beneficial in an early RNA world. We have investigated the interactions between the malachite green aptamer and its ligands. This investigation contributes to a better understanding of RNA aptamer interactions with small molecules which are crucial for drug development and RNA based catalysis. Equilibrium dialysis data suggests that MG binds exclusively within the binding pocket. On the other hand, pyronin Y which lacks the third phenyl ring of MG intercalates non-specifically. This confirms that all three phenyl rings have crucial interactions with RNA bases. Isothermal calorimetry data shows a more negative enthalpy value for the binding of tetramethylrosamine (TMR) to the MG aptamer than binding of MG to the MG aptamer. This agrees with the crystal structure of TMR bound to the MG aptamer that shows more extensive base stacking interactions compared to the MG : MG aptamer complex. TMR differs from MG by the addition of an oxygen between two of its phenyl rings, that gives TMR a more planar structure. MG binding to the MG aptamer shows an entropy value increase compared to TMR binding to the MG aptamer. This agrees with available ab initio calculations which show the development of an asymmetrical charge distribution across MG when bound to the MG aptamer.

The malachite green aptamer was originally engineered for binding specificity to malachite green (MG). The environment inside the aptamer’s electronegative binding pocket was previously harnessed to catalyze an ester cleavage via the stabilization of positively charged intermediates. In order to further explore and expand the catalytic potential of this molecule we have analyzed the binding and chemical properties of MG derivatives. The catalyzed reaction rate is approximately 2000-fold faster than the non-catalyzed reaction rate. This catalytic activity demonstrates the possible significance of electrostatic forces in RNA enzymes. The ability of RNA to catalyze different reactions depending on the substrate provided would have been beneficial in an early RNA world. We have investigated the interactions between the malachite green aptamer and its ligands. This investigation contributes to a better understanding of RNA aptamer interactions with small molecules which are crucial for drug development and RNA based catalysis. Equilibrium dialysis data suggests that MG binds exclusively within the binding pocket. On the other hand, pyronin Y which lacks the third phenyl ring of MG intercalates non-specifically. This confirms that all three phenyl rings have crucial interactions with RNA bases. Isothermal calorimetry data shows a more negative enthalpy value for the binding of tetramethylrosamine (TMR) to the MG aptamer than binding of MG to the MG aptamer. This agrees with the crystal structure of TMR bound to the MG aptamer that shows more extensive base stacking interactions compared to the MG : MG aptamer complex. TMR differs from MG by the addition of an oxygen between two of its phenyl rings, that gives TMR a more planar structure. MG binding to the MG aptamer shows an entropy value increase compared to TMR binding to the MG aptamer. This agrees with available ab initio calculations which show the development of an asymmetrical charge distribution across MG when bound to the MG aptamer.

The purpose of this research is that investigate the effects of time and concentration of exposure for the accumulation and depletion of malachite green and leucomalachite green in tilapia by pharmacokinetics. LC-MS/MS was used as the analytical instrument in this research, and the detection limit of malachite green and leucomalachite green is 0.51 ppb and 0.48 ppb. The results show that malachite green is unstable at high temperature. Addition of TMPD into the standard can stabilize malachite green. The malachite green in exposure water is easy to adhere to the fiberglass tub and cause the decreases of concentration of malachite green in water. The concentrations of malachite green and leucomalachite green in tilapia are positive related to the time and concentration of exposure. In experiments of exposure of malachite green, the highest concentration of malachite green occurs in liver, accumulation rate constant is 21.62 h-1. Liver is also the major organ for transforming malachite green into leucomalachite green, the net leucomalachite green accumulation rate constant is 213.67 h-1. In the period of water bath, Gill is the fastest organ for eliminating malachite green and leucomalachite green, the elimination rate constant is 0.7799 h-1 and 0.4658 h-1; the leucomalachite green concentration in fat is still increase until 6h of water bath.

A group of minerals typical of the oxidation zone of copper deposits was studied using chemical thermodynamics, mineral stability relationships, and petrography. It has been concluded that many processes, such as alteration, can be explained using thermodynamics and are compatible with natural relationships. A mineral assemblage consisting of basic carbonates of copper and zinc was investigated with carbon isotopes and mineral stability relationships. The results obtained are consistent with processes resulting from oxidation and leaching of a sulfide deposit followed by redeposition of copper and zinc in the zone of oxidation. Four processes have been suggested by which copper could be introduced into a near-surface environment from depth. Reactions which would occur under these conditions may result in formation of mesogene or hypogene malachite and chrysocolla. A vein deposit containing minerals typical of the zone of oxidation was investigated and it has been concluded that the minerals may have formed from a hydro-thermal solution related to near-surface volcanism.

The Cassenha Hill copper-gold prospect is situated in the Catabola area, Huambo Province, southwestern Angola. Geologically, the prospect is part of the Angolan Central Eburnean Zone (CEZ) and consists of Paleoproterozoic metasedimentary rock sequences which have been intruded by Eburnean granitoids at ± 2.1 Ga. The prospect itself comprises an area of 180 Km2 and has been intermittently explored since 2005 by Rift Valley Resources (RVR) and its associates. The Cassenha Hill prospect is characterized by the occurrence of partially altered and highly oxidized metasedimentary rocks (meta-mudstone, meta-siltstone, carbonate-rich rock, meta-sandstone, breccia, and quartzite), and altered isolated granitoids. This study represents the first detailed study of the prospect and aims to shed light on the characteristics of the various rock types (i.e., host and barren rocks), their source/provenance, styles of alteration, and the origin and/or type of the fluid responsible for the mineralization. Techniques applied include borehole core logging, petrography, whole-rock geochemistry (XRF and ICP-MS), and stable isotope geochemistry on samples collected on the surface and from exploration boreholes drilled as part of RVR exploration program. Overall, the petrographic and geochemical studies undertaken in the rocks of the Cassenha Hill prospect indicate the following: (1) The rocks are moderately to strongly fractured; (2) The rocks have experienced weak to moderate chemical weathering; (3) The rocks are compositionally immature and originated from felsic provenance; (4) The rocks are sulfur-poor, and lacking in sulfide minerals (5) The rocks are enriched in LREE and LILE elements and depleted in HREE and HFSE elements; (6) The mineralization is associated with chloritization alteration and predominantly occurs within and/or at the edges of quartz/chlorite-rich veins/fractures and is not restricted to any rock type. Two ore stages could be identified, namely, hypogene ore (stage I) consisting of pyrite ± chalcopyrite ± other copper sulfides, and supergene ore (stage II) consisting of malachite ± azurite ± chrysocolla, which represents the prevalent mineralization at the prospect. The δ 18O value of quartz veins range from +12.81 to +13.53‰, while the δD of chlorite minerals range from -51 to -45‰. Therefore, assuming fluid-rock interaction took place at ≈ 350oC, due to the presence of quartz, the fluid had δ 18OH20 values of about +8‰, which are typical of magmatic waters. On the other hand, at a temperature of ≈ 350oC, and with the difference between chlorite and water being -33.5‰, such fluids would have had δDH20 values of about -20‰ (δ 18OH20= -4‰), which are typical of meteoric waters. Although the various mineral phases have yielded different isotopic signatures, this study suggests that water is ultimately of meteoric origin but exchanged with hydrogen-poor magmatic rock, thus maintaining the meteoric signature. The continuous influx of meteoric waters within the fracture system led to the development of copper oxides such as malachite, azurite and chrysocolla, which possibly originated from the insitu oxidation of the hypogene sulfides. This signature, together with other field, petrographic and geochemical observations allows one to, tentatively, suggest that the Cassenha Hill prospect represents an extension of a polymetallic vein-type of porphyry Cu deposit that has been subjected to supergene processes at the weathering profile.

Au cours de cette thèse, de nouveaux dérivés organométalliques basés sur une structure triphénylméthylium ont été synthétisés. Ces composés, notamment grâce à leur structure multiplolaire, sont pressentis pour avoir des propriétés remarquables en optiques non linéaire (ONL) qui pourraient donner lieu à des développements appliqués dans plusieurs domaines. Ces caractéristiques, et plus précisément leur absorption biphotonique (A2P), en font des composés particulièrement intéressants pour l'industrie de pointe (microfabrication, imagerie, dispositifs optiques, etc.). Cependant, ces propriétés d'ONL et d'absorption biphotoniques n'ont été jusqu’à lors que peu étudiées, malgré leur potentiel prometteur. Dans un premier temps, une famille de nouveaux composés organiques présentant cette structure particulière, a donc été synthétisée afin de confirmer le potentiel d'absorption à deux photons de ces chromophores, notamment par des mesures Z-scan. Dans un second temps, la synthèse de d’analogues organométalliques ayant des groupes donneurs tels que «Fe(η5-C5Me5)(κ2-dppe)C≡C− , « Ru(Cl)(κ2-dppe)2C≡C− » ou ethynylferrocene a été réalisée et ces dérivés ont été extensivement caractérisés. Ces dérivés organométalliques devraient présenter des sections efficaces d’A2P (ainsi que des réponses ONL de troisième ordre) dans le proche-IR bien supérieures à celles de leurs analogues organique. De plus les groupements métalliques redox-actifs devraient permettre d’obtenir des chromophores électro-commutables. Dans cet objectif, les études déjà réalisées sur ces composés joints à l’étude à venir de leur propriétés ONL de troisième ordre et permettra de mieux comprendre les phénomènes electroniques sous-jacents à ces propriétés et le rôle joué par les parties organique et organométalliques de leur structure. / During this PhD, new organic and organometallic triphenylmethylium dyes were synthesized. Due to their multipolar structure, these compounds have been anticipated to possess strong nonlinear optical (NLO) properties which could be of interest in many fields. These characteristics, and more precisely their two-photon absorption (TPA) properties, make them attractive for the design of high technology materials (microfabrication, imaging, optical devices, etc…). However, their multiphoton absorption properties and other related nonlinear optical (NLO) effects have not been thoroughly investigated to date, in spite of their promising potential. In this respect, a family of organic derivatives has been synthesized to confirm their potential as two-photon absorbers, which was established thanks to Z-scan measurements. Organometallic compounds bearing electron-releasing groups such as «Fe(η5-C5Me5)(κ2-dppe)C≡C−» , « Ru(Cl)(κ2-dppe)2C≡C− » or ethynylferrocene were then synthesized and fully characterized. These organometallic dyes should possess larger TPA cross-sections (and also larger third-order NLO properties) in the NIR range than their organic counterparts. Furthermore, these redox-active metal centers permit access to electro-switchable molecules. In this respect, along with the data already gathered on these derivatives, the study of their cubic NLO properties in their different redox states will now contribute to a better understanding of the underlying electronic phenomena and the role played by the organic and organometallic moieties in such architectures.

This research investigate the matrix effect, operation time, cost and solvent comsumption for triarylmethanes and corresponding metabolites in different aquaculture products by different extraction methods. Triarylmethane was determined by LC-ESI-MS/MS in positive mode. The analytical method validation were followed the regulation of 2002/657/EC. HPLC separation was conducted with the RP-18 column. The mobile phases consisted of 0.5 mM ammonium acetate buffer (pH 3.8, adjusted with acetic acid) ¡V acetonitrile (contained 0.1% formic acid) solution. The ratios of standard deviation to average residual time for all compounds are less than 0.05. The ion ratio is stable and allowed by the regulation of 2002/657/EC. The regression constant of calibration curve is in the range from 0.998 to 0.999. The CC£\ for MG, LMG, CV, LCV are 0.09 ¡Ó 0.05, 0.19 ¡Ó 0.14, 0.15 ¡Ó 0.13, 0.15 ¡Ó 0.10 £ggkg-1, respectively. The CC£] for MG, LMG, CV, LCV are 0.09 ¡Ó 0.05, 0.19 ¡Ó 0.14, 0.15 ¡Ó 0.13, 0.15 ¡Ó0.10 £ggkg-1, respectively. The results for SPE and liquid-liquid extraction are not significantly different; the liquid-liquid extraction have shorter operation time, cheaper cost and less solvent consumption in comparison with SPE.