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Análise de especiação e fracionamento de biocidas de zinco (Piritionato de zinco, Zineb e Ziram) utilizando SPE, DGT, HPLC e ICP-MS em água estuarina / Speciation analysis and fractionation of zinc biocides (Zinc Pyrithione, Zineb and Ziram) using SPE, DGT, HPLC and ICP-MS in estuarine waterRolisola, Ana Marta Cavinato Marchini [UNESP] 02 May 2018 (has links)
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Previous issue date: 2018-05-02 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Atualmente, cerca de 18 compostos são utilizados como biocidas de reforço (metálicos) em tintas anti-incrustantes, como por exemplo Piritionato de Zinco (Zn(PT)2), Zineb e Ziram. É relevante o desenvolvimento de um método analítico para determinação das concentrações ambientais de biocidas metálicos. O presente estudo teve como objetivos i)desenvolver uma metodologia de extração em fase sólida (SPE) e cromatografia líquida de alta eficiência acoplada (HPLC) ao espectrômetro de massas com plasma acoplado indutivamente (ICP-MS) para determinação de Zn(PT)2, Zineb e Ziram e ii) quantificar, in lab, a fração lábil total do Piritionato de Zinco, Zineb e Ziram e in situ, a fração lábil total do zinco, utilizando a técnica de difusão em filmes finos por gradiente de concentração (DGT) em solução padrão e água estuarina, respectivamente. Na técnica de SPE foi utilizado o sorbente de sílica funcionalizado com fenil apresentando excelente retenção para Zn(PT)2, Zineb e Ziram (94 ± 0,1%, 85 ± 0,04% e 93 ± 0,1%, respectivamente) e recuperações entre 85% e 110%. Na determinação dos biocidas de zinco utilizando o acoplamento HPLC-VGroove-ICP-MS com diluição pós coluna cromatográfica, a fase móvel composta por metanol e 0,006 mol L-1 de acetato de amônio (50:50, v v-1) apresentou o melhor desempenho na separação do Zn(PT)2, Zineb, Ziram. A curva analítica obtida para o Zn(PT)2 apresentou coeficiente de correlação, LD e LQ satisfatórios para os isótopos 64Zn (0,98, 0,575 mg L-1, 1,916 mg L-1), 66Zn(0,99, 0,480 mg L-1 , 1,600 mg L-1), 68Zn(0,98, 0,602 mg L-1, 2,007 mg L-1). Na técnica DGT foi utilizado o agente ligante resina Chelex® 100 para avaliar a labilidade do Zn(PT)2, Zineb e Ziram em água estuarina. Os resultados demonstraram que a fração lábil total do Zn ficou em torno de 100% para o Zineb (111%) e Ziram (109%), ou seja, estes biocidas formaram espécies totalmente lábeis na amostra de água estuarina e para Zn(PT)2 foi de 75% indicando espécies parcialmente lábeis. Os resultados obtidos na técnica SPE, no acoplamento HPLC-VGroove-ICP-MS e DGT demonstraram que os métodos apresentam desempenho satisfatório para a determinação de Piritionato de Zinco, Zineb e Ziram. / About 18 compounds are used as booster biocides (metal) in antifouling paints such as Zinc Pyrithione (Zn(PT)2), Zineb and Ziram. It is important to develop an analytical method for determining of the environmental concentrations of zinc biocides. The present study had as objectives i) to develop a solid phase extraction (SPE) and high performance liquid chromatography (HPLC) coupled to the inductively coupled plasma mass spectrometer (ICP-MS) for the determination of Zn(PT)2, Zineb and Ziram and ii) quantify in lab the total labile fraction of Zn(PT)2, Zineb and Ziram and in situ the total labile fraction of zinc using the diffusive gradient in thin films (DGT) technique in standard solution and estuarine water, respectively. In the SPE technique, the silica sorbent functionalized with phenyl presented excellent retention for Zn(PT)2, Zineb and Ziram (94 ± 0.1%, 85 ± 0.04% and 93 ± 0.1%, respectively) and recoveries between 85% and 110%. In the determination of zinc using the HPLC-VGroove-ICP-MS coupling with post-column chromatographic dilution, the mobile phase composed of methanol and 0.006 mol L-1 of ammonium acetate (50:50, v v-1) of presented the best performance in the separation of Zn(PT)2, Zineb and Ziram. The analytical curve obtained for Zn(PT)2 presented satisfactory correlation coefficient, LD and LQ for the isotopes 64Zn (0.98, 0.575 mg L -1, 1.916 mg L-1), 66Zn (0.99, 0.480 mg L-1, 1.600 mg L-1), 68Zn (0.98, 0.602 mg L-1, 2.007 mg L-1). In the DGT technique, the Chelex® 100 resin binder was used to evaluate the lability of the zinc biocides Zn(PT)2, Zineb and Ziram in estuarine water. The results showed that the total labile fraction of Zn was around 100% for Zineb (111%) and Ziram (109%), that is, these biocides formed totally labile species in the estuarine water sample and for Zn(PT)2 was 75% indicating partially labile species. The results obtained in the SPE technique in the HPLC-VGroove-ICP-MS coupling and DGT demonstrated that the methods present satisfactory performance for the determination of Zn(PT)2, Zineb and Ziram. / CNPq: 164326/2015. / FAPESP: 2015/03397-4.
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Inhibition of the Ubiquitin Proteasome System Enhances Long-Term Depression in Rat Hippocampal SlicesLouie, LeeAnn N 01 April 2013 (has links)
The ubiquitin proteasome system (UPS) depends on three enzymes called E1, E2, and E3 to ubiquitinate proteins and several isopeptidases to de-ubiquitinate them. Ubiquitination serves as a post-translational modification that either tags proteins for degradation by the proteasome or serves to modulate their function. This dynamic system plays a role in synaptic plasticity and dysfunction of the UPS is associated a variety of neurodegenerative diseases. In this study, three inhibitors the UPS, ziram, clasto-lactacystin β-lactone (lactacystin) and G5 were employed to illuminate involvement of the UPS in long-term and short term plasticity in area CA1 of rat hippocampal slices. Ziram, lactacystin and G5 inhibits the E1 ubiquitin-activating enzyme, the proteasome and isopeptidases, respectively. It was found that UPS inhibition enhanced long-term plasticity, by specifically increasing the magnitude of long-term depression (LTD) and altered short term plasticity, measured with paired pulse facilitation (PPF), to varying degrees. These findings establish that the UPS may play a regulatory role in LTD and PPF, and the changes in PPF further indicate that the UPS may be acting presynaptically. Overall, the results suggest ubiquitination and proteasome-mediated proteolysis are important in both long-term and short-term plasticity.
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Inhibition of the Ubiquitin Proteasome System Enhances Long-Term Depression in Rat Hippocampal SlicesLouie, LeeAnn N 01 January 2013 (has links)
The ubiquitin proteasome system (UPS) depends on three enzymes called E1, E2, and E3 to ubiquitinate proteins and several isopeptidases to de-ubiquitinate them. Ubiquitination serves as a post-translational modification that either tags proteins for degradation by the proteasome or serves to modulate their function. This dynamic system plays a role in synaptic plasticity and dysfunction of the UPS is associated a variety of neurodegenerative diseases. In this study, three inhibitors the UPS, ziram, clasto-lactacystin β-lactone (lactacystin) and G5 were employed to illuminate involvement of the UPS in long-term and short term plasticity in area CA1 of rat hippocampal slices. Ziram, lactacystin and G5 inhibits the E1 ubiquitin-activating enzyme, the proteasome and isopeptidases, respectively. It was found that UPS inhibition enhanced long-term plasticity, by specifically increasing the magnitude of long-term depression (LTD) and altered short term plasticity, measured with paired pulse facilitation (PPF), to varying degrees. These findings establish that the UPS may play a regulatory role in LTD and PPF, and the changes in PPF further indicate that the UPS may be acting presynaptically. Overall, the results suggest ubiquitination and proteasome-mediated proteolysis are important in both long-term and short-term plasticity.
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Investigation of Thiol-Containing Biomarkers and Their Role in the ExposomeGastineau-Stevens, Tracy 01 January 2019 (has links)
Exposomics is an emerging area of study that looks at how the environment around a person or persons affects their overall health. Biomarkers have emerged as useful tools to better understand how the exposome affects a person. In this work, we investigate two potential endogenous biomarkers, homocysteine and glutathione that have been previously implicated in a number of diseases that have been linked to environmental causes. We also investigated an environmental exposure, the fungicide Ziram, which epidemiologically has been linked to diseases. In our investigation, we utilized capillary electrophoresis and capillary electrophoresis-mass spectrometry to develop a method for homocysteine and identify a derivative to keep it from auto-oxidizing. We utilized mass spectrometry to identify the best ionization technique to detect Ziram and confirmation of where it binds on thiol-containing molecules. We also developed a method to extract glutathione-Ziram from serum and utilized liquid chromatography-mass spectrometry to begin a validation of glutathione-Ziram. Although future work is needed, we believe that this work was the beginning steps to understand biomarkers and their role in the exposome.
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