Devido à ampla utilização do cádmio nas indústrias, muitos solos encontram-se contaminados. Vários estudos com bioindicadores estão sendo realizados para detectar cádmio em solos, sendo a maioria com minhocas (Eisenia fetida) e plantas, contudo estes testes são laboriosos e longos. Os micro-organismos tem se mostrado uma alternativa promissora para esta aplicação, pois são de fácil cultivo e manutenção, além de apresentarem uma rápida resposta às alterações ambientais. Desta forma, o objetivo deste trabalho foi utilizar diferentes gêneros de leveduras como bioindicadores de cádmio no solo. Para tanto foram avaliadas dezoito linhagens de leveduras, das quais foram selecionadas três quanto à sensibilidade na presença de cádmio. A levedura Torulopsis utilis var. thermophilus (IZ214) apresentou alta sensibilidade, a Candida utilis (IZ300) sensibilidade mediana e Saccharomyces cerevisiae (Pedra) a menor sensibilidade. O crescimento foi avaliado por espectrometria, através de leituras de D.O. e pela técnica do Trifeniltetrazólio (TTC) para avaliação da viabilidade celular. O uso do TTC mostrouse mais adequado nos bioensaios com leveduras evidenciando as células metabolicamente ativas. Foi avaliado o crescimento das leveduras em extratos de solo com cádmio obtidos pelo extrator CaCl2 0,01 mol L-1. Observou-se que o crescimento das leveduras na maioria dos tratamentos foi igual ou superior ao controle. Isso ocorreu devido à adsorção do cádmio à matéria orgânica e outros elementos. Para comprovar a adsorção do cádmio à matéria orgânica, foi realizado ensaio com a levedura S. cerevisiae (Pedra) onde ao extrato de solo obtido foi adicionado solução de Cd2+. Através da leitura de D.O. foi observada uma taxa de inibição de 75% para 100 mg L-1 de cádmio e, pela técnica do TTC, a taxa de inibição de 100% ocorreu na concentração de 44 mg L-1. Ensaios com sementes foram realizados para avaliar a germinação e crescimento na presença de cádmio. Sementes de Cucumis sativus foram expostas à solução de Cd2+, ocorrendo 100% de germinação e apresentando DL50 de 7,33 mg L-1. Este resultado foi maior comparado aos obtidos para as leveduras avaliadas, as quais apresentaram uma DL50 de 0,89 mg L-1 para a levedura T. utilis (IZ214) e DL50 de 1,86 mg L-1 para a S. cerevisiae (Pedra). As sementes de Zea mays foram expostas ao extrato de solo com cádmio, onde foi obtido uma DL50 de 33,9 ± 3,0 mg L-1 e, nas mesmas condições para a levedura S. cerevisae (Pedra), a DL50 foi de 29,8 mg L-1. Os resultados obtidos mostraram uma proximidade de valores nos ensaios com extrato de solo com cádmio entre a semente de milho e levedura. Com isso, foi possível concluir que as leveduras são sensíveis ao cádmio e podem ser uma nova opção de bioindicadores. Além disso, as leveduras e principalmente a S. cerevisiae possuem um alto grau de homologia com os eucariotos superiores, permitindo assim o estudo de aspectos de toxicidade relevantes a biologia humana. / Due to extensive use of cadmium in industries, many soils are contaminated. Several studies are being conducted with biomarkers to detect cadmium in soils, mostly with earthworms (Eisenia fetida) and plants, however, these tests are laborious and lengthy. Micro-organisms have been presented as an alternative to this application, as they are easy to grow and maintain, and offer a rapid response to environmental changes. Thus, the aim of this study was to use different kinds of yeasts as indicators of cadmium in soil. Eighteen yeasts strains were evaluated, from which three were selected for their sensitivity in the presence of cadmium. The yeast Torulopsis utilis var. thermophilus (IZ214), showed high sensitivity, Candida utilis (IZ300), showed a median sensitivity and Saccharomyces cerevisiae (Ale Yeast) a showed lower sensitivity. Yeasts growth was assessed through spectrophotometry, by reading O.D. and by the technique Triphenyltetrazolium (TTC) to assess cell viability. The use of TTC was more appropriate as an indicator of cell viability in yeast bioassays showing metabolically active cells. We evaluated the growth of yeasts in soil extracts with cadmium obtained by extraction with CaCl2 0.01 mol L-1. It was observed that the growth of the yeast on most of the treatments was equal or superior to the control. This was due to the adsorption of cadmium to organic matter and other elements. To prove the adsorption of cadmium to organic matter, an essay was performed with the yeast S. cerevisiae (Ale Yeast), in which the soil extract solution obtained was added with Cd2+. By reading the O.D. it was observed an inhibition rate of 75% for 100 mg L- 1 cadmium and, by the TTC technique, the highest rate of 100% inhibition occurred at a concentration of 44 mg L-1. Seeds trials were conducted to evaluate germination and growth. Cucumis sativus seeds were exposed to a solution of Cd2+, resulting in 100% of germination and showing a LD50 of 7.33 mg L-1, which was greater than the one measured for yeasts, who had an LD50 of 0.89 mg L-1 to the yeast T. utilis (IZ214) and LD50 of 1.86 mg L-1 for S. cerevisiae (Ale Yeast). The seeds of Zea mays were exposed to soil extract containing cadmium, in which it was noticed a LD50 of 33.9 ± 3.0 mg L-1 and, by having the same conditions for the yeast S. cerevisiae (Ale Yeast), the LD50 was of 29.8 mg L-1. The results showed similar values in tests with soil extract with cadmium comparing the corn seed and the yeast. Thus, it was concluded that the yeasts are sensitive to cadmium and may be a new option bioindicators. Also, yeasts, in special S. cerevisiae, have a high degree of homology with higher eukaryotes, therefore allowing the study of relevant toxicity aspects in human biology.

O presente estudo teve por objetivo avaliar a qualidade dos compartimentos água e sedimento do rio Monjolinho, localizado na sub-bacia hidrográfica do Alto Jacaré-Guaçu, na região centro-norte do estado de São Paulo. Para tanto, foram realizadas análises limnológicas e ecotoxicológicas em seis estações de amostragem ao longo do rio, durante cinco campanhas de coleta (julho, outubro de 2003 e janeiro, abril, julho de 2004). Os ensaios de toxicidade com amostras ambientais foram realizados com os cladóceros planctônicos Daphnia similis e Ceriodaphnia dubia como organismos-teste. Adicionalmente, foram realizados testes de sensibilidade aos metais cádmio e cobre utilizando Daphnia similis e Ceriodaphnia dubia, com o intuito de verificar se as concentrações permitidas pelo CONAMA 357/05 para estes metais são adequadas para a proteção da vida aquática em rios de classe 2. Os resultados obtidos quanto as análises limnológicas apontaram três trechos distintos do rio Monjolinho considerando-se a qualidade da água: a) trecho não poluído a ligeiramente poluído (estação 1); b) trecho poluído (estações 2, 3, e 4) e c) trecho fortemente poluído (estações 5 e 6). Os ensaios de toxicidade com amostras ambientais indicaram uma maior toxicidade do sedimento do que da água, particularmente nos períodos de outubro de 2003, janeiro e abril de 2004. Neste contexto, os testes com sedimento foram mais adequados para uma avaliação da real condição de toxicidade do sistema. Quanto aos testes de sensibilidade, os resultados para cádmio foram superiores ao limite estabelecido pela resolução 357 do CONAMA/05 (1 &#956g/L), demonstrando adequabilidade do valor estabelecido para a manutenção da vida aquática em rios de classe 2, no que se refere ao efeito isolado deste metal. Já os valores encontrados nos testes de sensibilidade ao cobre foram inferiores ao limite para cobre dissolvido estabelecido pelo CONAMA 357/05 (9 &#956g/L), mostrando que o valor definido para a manutenção da biota aquática ainda não está adequado, levando-se em consideração o efeito isolado deste contaminante. / The present study aimed to evaluate water and sediment quality of Monjolinho river, located at High Jacaré-Guaçu water basin, in the center of São Paulo state. Limnological and ecotoxicological analyses were carried out in six sampling stations along the river, during five sampling periods (July, October of 2003 and January, April, July of 2004). Bioassays with environmental samples were carried out with planktonic crustaceans, Daphnia similis and Ceriodaphnia dubia, as test organisms. Additionally, tests of sensibility to cadmium and copper were carried out with the same species to verify if their allowed concentrations by CONAMA 357/05 are appropriate for the protection of the aquatic life in class 2 rivers. The results of the limnological analyses indicated three distinct regions of water quality: a) not polluted to slightly polluted region (station 1); b) polluted region (stations 2, 3, and 4) and c) highly polluted region (stations 5 and 6). The bioassays with environmental samples indicated greater sediment toxicity than water toxicity, particularly in October of 2003, January and April of 2004. The tests of sensibility to cadmium, showed higher values than the limit established by resolution 357 of CONAMA/05 for this metal (1 &#956g/L), demonstrating adequacy of the established value for the maintenance of the aquatic life in class 2 waters, concerning the isolated effect of cadmium. However, the tests of sensibility to copper, presented lower values than its limit established by CONAMA 357/05 (9 &#956g/L), showing that the determined value of copper for the maintenance of the aquatic biota is still not adequate, considering the isolated effect of this pollutant.

O cádmio (Cd) é um metal pesado e dos mais abundantes elementos encontrados no ambiente. Existem evidências de sua relação coma osteopenia, osteoporose, e osteomalacia e fragilidade do tecido ósseo. Este estudo visa avaliar o efeito do pH da água de beber na gênese da alteração óssea provocada pela intoxicação por cádmio. Neste estudo, foram utilizados90 ratosWistar (Ratus Norvegicus albinus), adultos, machos,divididos em 6 grupos, aos quais foram administrados: A -solução de cloreto de Cd(400mg/L) com pH neutro (pH 7,0); B -solução de cloreto de Cd(400mg/L) com pH ácido (pH 5,0); C -solução de cloreto de Cd(400mg/L) com pH básico (pH 8,0). D -pH ácido (pH 5,0); E -pH básico (pH 8,0); F -pH neutro (pH 7,0). Nofêmur esquerdo de cada rato avaliou-se a densidade óssea, por meio do densitômetro de dupla emissão (DEXA), ensaiosbiomecânicos e escala de HU na tomografia computadorizada espiral.Os resultados demostram que a densidade óssea reduziunos grupos que receberam cádmio e no grupo sem administração de cádmio para o pH 5 ocorreu uma redução da densidade mineral óssea (DMO) e do conteúdo mineral ósseo (CMO). A rigidez biomecânica mostrou-se aumentada para o grupocom pH 5 sem cádmio. Como conclusão geral o cádmio reduziu a densidade óssea. / The cadmium (Cd) is a heavy metal, one of the most abundant elements found in the environment. There are evidences of its relationship in osteopenia, osteoporosis e osteomalacia and fragility of the bone tissue. This study aims to evaluatethe effect of the pH of the drinking water in the bonealteration origin caused by cadmium intoxication. This study envolved90 wistar rats (Ratus Norvegicus albinus), adults, males,divided in 6groups, were witch one receved: A -cadmium choride solution (400mg/L)withneutral ph (pH 7,0); B -cadmium choride solution(400mg/L) with acid ph (pH 5,0); C -cadmium choride solution(400mg/L)with basic ph(pH 8,0); D -with acid ph (pH 5,0); E -basic ph (pH 8,0); F -neutral pH (pH 7,0).Left femurs from each rat were evaluatedbybone density,DEXA,biomechanictest,HU scale from computerized tomography. The results shows that bone density became lower in the groups that received cadmium. In that wich received no cadmium with pH 5 ocurred an lower level of bone mineral density (BMO) andbone mineral content (BMC).The bone rigidity proved increased in the pH 5 with no cadmium. As a general conclusion, cadmium reduced the bone density.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / This research describes the process of obtaining a photovoltaic cell, since getting electrical conductor glasses used for the flow of electrons coming from the photovoltaic effect until the deposition of thin films of semiconductor titanium dioxide (TiO2) and cadmium sulfide (CdS) at each of these glasses. The use of natural or synthetic dyes deposited on titanium dioxide layer has the objective to increase the absorption spectrum of the TiO2, since sunlight emits most of its energy in the frequency range of visible light. After joining the two glasses with thin films deposited over TiO2 plus dye and CdS, it was used a potassium triiodide electrolyte for regeneration and consequently the activation of photovoltaic solar cell. After mounting the cell concerned, tests of photoactivity have been performed by exposing the cells to sunlight collected for specified periods and the values of voltage and photocurrent generated. Theoretical studies have been conducted to mathematical modeling of the behavior of the solar cell mounted, and then we have analyzed the efficiency of converting solar energy into electrical energy. The constituents of the cell have been characterized by the techniques of X-ray diffraction (XRD) and scanning electron microscopy (SEM) for analyzing the porosity, uniformity and other physical parameters of thin films. / O presente trabalho descreve o processo de obtenÃÃo de uma cÃlula fotovoltaica, desde a obtenÃÃo de vidros condutores elÃtricos utilizados para o fluxo dos elÃtrons oriundos do efeito fotovoltaico, atà a deposiÃÃo dos filmes finos dos semicondutores diÃxido de titÃnio (TiO2) e sulfeto de cÃdmio (CdS) em cada um dos vidros. O uso de corantes naturais ou sintÃticos na camada depositada de diÃxido de titÃnio possuiu como objetivo aumentar o espectro de absorÃÃo do mesmo, uma vez que a luz solar emite uma grande parte de sua energia na faixa de frequÃncia da luz visÃvel. Depois de unir os dois vidros com os filmes finos depositados de TiO2 mais corante e o CdS, utilizou-se o eletrÃlito de tri-iodeto de potÃssio para a regeneraÃÃo e consequentemente a ativaÃÃo da cÃlula solar fotovoltaica. ApÃs a montagem da cÃlula em questÃo, foram realizados testes de fotoatividade, expondo as cÃlulas ao sol por perÃodos determinados e coletados os valores da fotocorrente gerada e a tensÃo, alÃm disso, foram realizados estudos teÃricos para modelagem matemÃtica do comportamento da cÃlula solar montada e em seguida analisou-se a eficiÃncia de conversÃo de energia solar em energia elÃtrica. Os constituintes da cÃlula foram caracterizados pelas tÃcnicas de difraÃÃo de raios-X (DRX) e microscopia eletrÃnica de varredura (MEV) para analisar a porosidade, uniformidade e outros parÃmetros fÃsicos dos filmes finos.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-04-27T18:09:30Z No. of bitstreams: 1 2015 - Jessica Coelho Melo.pdf: 1651769 bytes, checksum: 37df9227b9a25c24297ba5364064be27 (MD5) / Made available in DSpace on 2018-04-27T18:09:30Z (GMT). No. of bitstreams: 1 2015 - Jessica Coelho Melo.pdf: 1651769 bytes, checksum: 37df9227b9a25c24297ba5364064be27 (MD5) Previous issue date: 2015-08-21 / CNPq / The gray leaf spot caused by Stemphylium solani, has occasioned losses in the tomato crop (Solanum lycopersicum L.) in several regions of Brazil. Although there are resistant cultivars, the control has been made, essentially, with application of fungicides. These, despite the practicality and efficiency can lead to the accumulation of polluting substances in the air and in the fruits. This study aimed to evaluate: 1) the chemical control efficiency of the disease with commercial fungicides registered for crop and with alternative products such as syrups and plant extracts; 2) the influence of these treatments on the development and production of tomato; 3) the contribution of metals in the system and its contents in leaves and fruits; 4) to compare the contents of metals in the fresh mass of the fruits with the limits allowed by the legislation. Three trials were carried out, one in the greenhouse and two in the field, and different products were compared: mancozebe, tebuconazole, copper oxychloride, vi?osa mixture, bordeaux mixture, lime sulfur, garlic extract and water. Were evaluated the progress of the disease, the production and the supply of metals in the soil, plants and fruits (Cd, Co, Cr, Cu, Fe, Mn, Pb, Ni and Zn). The disease occurred on average at low intensity and did not affect the fruit production, which did not allow an adequate evaluation of the efficiency of the treatments. Among all the products tested, bordeaux and vi?osa mixtures and mancozebe were the most efficient in controlling the disease, however, without affecting the accumulation of fresh and dry mass of the plants and productivity. Bordeaux and vi?osa mixtures were the products that contributed the most to the incorporation of metals to the agrosystem followed by mancozebe and copper oxychloride. The concentration of metals in the fruits was below the maximum limit allowed by the MERCOSUL Technical Regulation, however, it deserves attention in view of fact that the Cd values found in the fruits are very close to the allowed limit, especially in the treatments with vi?osa mixture, oxychloride copper and bordeaux mixture. The continuous use of fungicides and vi?osa and bordeaux mixtures can contribute to the accumulation of heavy metals in the agrosystem. New studies addressing this topic should be made. / A mancha-de-estenf?lio, causada por Stemphylium solani, tem ocasionado perdas na cultura do tomateiro (Solanum lycopersicum L.) em v?rias regi?es do Brasil. Apesar de existirem cultivares resistentes, o controle tem sido feito, essencialmente, com aplica??o de fungicidas. Estes, apesar da praticidade e efici?ncia podem levar ao ac?mulo de subst?ncias poluentes no ar e nos frutos. O presente trabalho teve como objetivos avaliar: 1) a efici?ncia do controle qu?mico da doen?a com fungicidas comerciais registrados para a cultura e com produtos alternativos como caldas e extratos de plantas; 2) a influ?ncia destes tratamentos no desenvolvimento e produ??o do tomateiro; 3) o aporte de metais no sistema e os seus teores nas folhas e frutos; 4) comparar os teores de metais na massa fresca dos frutos com os limites permitidos pela legisla??o. Realizaram-se tr?s ensaios, um em casa-de-vegeta??o e dois no campo e compararam-se diferentes produtos: mancozebe, tebuconazole, oxicloreto de cobre, calda vi?osa, calda bordalesa, calda sulfoc?lcica, extrato de alho e ?gua. Avaliaram-se o progresso da doen?a, a produ??o e o aporte de metais no solo, plantas e frutos (Cd, Co, Cr, Cu, Fe, Mn, Pb, Ni e Zn). A doen?a ocorreu em m?dia a baixa intensidade e n?o afetou a produ??o de frutos, o que n?o permitiu uma adequada avalia??o da efici?ncia dos tratamentos. Dentre todos os produtos testados, as caldas bordalesa e vi?osa e o mancozebe foram os mais eficientes no controle da doen?a, por?m, sem afetar o ac?mulo de massa fresca e seca das plantas e a produtividade. As caldas bordalesa e vi?osa foram os produtos que mais contribu?ram para a incorpora??o de metais ao agrossistema seguido do mancozebe e do oxicloreto de cobre. A concentra??o de metais nos frutos esteve abaixo do limite m?ximo permitido pelo Regulamento T?cnico MERCOSUL, no entanto, merece aten??o tendo em vista o fato dos valores de Cd encontrados nos frutos estarem muio pr?ximo do limite permitido, especialmente nos tratamentos com calda vi?osa, oxicloreto de cobre e calda bordalesa. O uso cont?nuo de fungicidas e das caldas vi?osa e bordalesa podem contribuir para o ac?mulo de metais pesados no agrossistema. Novos estudos abordando este tema devem ser feitos.

Ho, Yee Man Martina = 硒化鎘三維納米結構之製作及其感應脫氧核糖核酸之應用潛能 / 何綺雯. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references. / Abstract also in Chinese. / Ho, Yee Man Martina = Xi hua ge san wei na mi jie gou zhi zhi zuo ji qi gan ying tuo yang he tang he suan zhi ying yong qian neng / He Qiwen. / Chapter Chapter 1 --- Introduction / Chapter 1 --- Photovoltaic properties of CdSe --- p.1 / Chapter 1.1 --- Quantum size effect --- p.1 / Chapter 1.2 --- Synthesis of CdSe nanostructures --- p.3 / Chapter 1.3 --- Electrochemical sensing of CdSe nanostructures --- p.4 / Chapter 1.3.1 --- Surface passivation and functionalization of CdSe nanostructures --- p.5 / Chapter 1.4 --- Electronic properties of nanocrystalline semiconductor electrode --- p.6 / Chapter 1.4.1 --- Band alignment --- p.6 / Chapter 1.4.2 --- Interfacial charge transfer process --- p.9 / Chapter 1.4.3 --- Surface traps and adsorbed molecules --- p.10 / Chapter 1.4.4 --- DNA molecules as a capping group --- p.11 / Chapter 1.5 --- Literatures review in DNA sensing --- p.12 / Chapter 1.6 --- Present study --- p.14 / Chapter 1.6.1 --- Objective --- p.14 / Chapter 1.6.2 --- General methodology --- p.15 / Chapter Chapter 2 --- Experimental / Chapter 2.1 --- Introduction into the instrumentation of this project --- p.21 / Chapter 2.2 --- CHI Electrochemical workstation --- p.22 / Chapter 2.2.1 --- Linear sweep voltammetry --- p.24 / Chapter 2.2.2 --- Cyclic voltammetry --- p.24 / Chapter 2.2.3 --- Multiple potential step --- p.25 / Chapter 2.3 --- CEM Microwave-assisted chemical synthesizer --- p.27 / Chapter 3.1 --- Morphological examination by scanning electron microscopy --- p.28 / Chapter 3.2 --- Elemental analysis by energy dispersive x-ray spectroscopy --- p.30 / Chapter 3.3 --- Crystal structure analysis by x-ray diffraction --- p.31 / Chapter 3.4 --- Surface compositional analysis by x-ray photoelectron spectroscopy --- p.32 / Chapter 3.5 --- Transmission electron microscopy --- p.34 / Chapter Chapter 3 --- Synthesis of 3D nanostructured CdSe multipod electrodes / Chapter 3.1 --- Introduction into the synthesis of CdSe MP electrode --- p.35 / Chapter 3.2 --- Recipe for the synthesis of CdSe NPs --- p.36 / Chapter 3.3 --- The synthesis of CdSe MPs --- p.37 / Chapter 3.3.1 --- Tuning the experimental parameters: Reaction temperature --- p.37 / Chapter 3.3.2 --- Tuning the experimental parameters: Reaction hold time --- p.46 / Chapter 3.3.3 --- Tuning in experimental parameters: Precursor molar ratio --- p.50 / Chapter 3.4 --- The fabrication of MP CdSe on a conductive substrate --- p.54 / Chapter 3.4.1 --- The electrodeposition of CdSe thin films on ITO/glass substrates --- p.55 / Chapter 3.4.2 --- The growth of CdSe MPs on CdSe/ ITO/glass --- p.57 / Chapter 3.5 --- The characterization of MP CdSe electrode --- p.57 / Chapter Chapter 4 --- Electrical and opto-electric characteristics of CdSe MP electrodes and their applications as platforms for the DNA recognition / Chapter 4.1 --- Introduction to the property characterization of CdSe MP electrodes --- p.62 / Chapter 4.2 --- DNA surface attachment --- p.64 / Chapter 4.2.1 --- Mechanism of DNA surface anchoring --- p.65 / Chapter 4.3 --- I-V characterization in PBS --- p.69 / Chapter 4.3.1 --- Experimental procedures of the I-V tests in PBS --- p.70 / Chapter 4.3.2 --- Results and discussions of I-V tests in PBS --- p.72 / Chapter 4.3.2.1 --- Exercising as-prepared CdSe MP electrode --- p.74 / Chapter 4.3.2.2 --- I-V characteristics of CdSe MP electrodes before and after ssDNA attachment --- p.75 / Chapter 4.3.2.3 --- I-V characteristics of CdSe MP electrodes before and after the dsDNA attachment --- p.76 / Chapter 4.3.2.4 --- "Photo-response of bare CdSe MP, ssDNA/CdSe MP and dsDNA/CdSe electrodes" --- p.77 / Chapter 4.4 --- "Photovoltaic I-V measurement in I3""/I"" redox electrolyte" --- p.79 / Chapter 4.4.1 --- Experimental procedures --- p.79 / Chapter 4.4.2 --- Results and discussions --- p.80 / Chapter 4.5 --- Possible application implied by the results --- p.88 / Chapter 4.5.1 --- DNA base pair mismatch identification --- p.91 / Chapter 4.5.2 --- Field-assisted DNA hybridization acceleration process --- p.92 / Chapter Chapter 5 --- Conclusions / Chapter 5.1 --- Conclusions --- p.95

Man, Ka Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 101-126). / Abstracts in English and Chinese. / Chapter I. --- Title page --- p.i / Chapter II. --- Thesis committee --- p.ii / Chapter III. --- Acknowledgements --- p.iii / Chapter IV. --- Abstract (English) --- p.iv / Chapter V. --- Abstract (Chinese) --- p.vi / Chapter VI. --- Table of contents --- p.vii / Chapter VII. --- List of abbreviations --- p.xiii / Chapter VIII. --- List of figures --- p.xv / General introduction --- p.1 / Chapter Chapter 1: --- Literature review --- p.4 / Chapter 1.1. --- Cadmium --- p.5 / Chapter 1.1.1. --- Cadmium - Ways of uptake in human and aquatic life --- p.5 / Chapter 1.1.2. --- Cadmium - Toxic effects in fish --- p.6 / Chapter 1.2. --- Cortisol --- p.11 / Chapter 1.2.1. --- Cortisol - General information and its regulations --- p.11 / Chapter 1.2.2. --- Cortisol - Functions --- p.12 / Chapter 1.3. --- Thyroid hormones --- p.14 / Chapter 1.3.1. --- THs - General information and its regulations --- p.14 / Chapter 1.3.2. --- THs - Functions --- p.15 / Chapter 1.4. --- Growth hormone --- p.18 / Chapter 1.4.1. --- GH - General information and its regulations --- p.18 / Chapter 1.4.2. --- GH - Functions --- p.20 / Chapter 1.5. --- Insulin-like growth factor --- p.22 / Chapter 1.5.1. --- IGF-I - General information and its regulations --- p.22 / Chapter 1.5.2. --- IGF-I - Functions --- p.24 / Chapter 1.6 --- Metallothioneins --- p.26 / Chapter 1.6.1. --- MTs - Definition and Classification --- p.26 / Chapter 1.6.2. --- MTs - Functions --- p.27 / Chapter 1.7. --- Glucose-6-phosphate dehydrogenase --- p.31 / Chapter 1.7.1. --- G6PDH - General information and its regulations --- p.31 / Chapter 1.7.2. --- G6PDH ´ؤ Functions --- p.32 / Chapter Chapter 2: --- "Effects of cadmium exposure on the endocrine status of silver sea bream, Sparus sarba" --- p.34 / Chapter 2.1. --- Introduction --- p.35 / Chapter 2.2. --- Materials and methods --- p.37 / Chapter 2.2.1. --- Overall experimental design --- p.37 / Chapter 2.2.2. --- In vivo exposure to waterborne cadmium --- p.37 / Chapter 2.2.2.1. --- Experimental animals --- p.37 / Chapter 2.2.2.2. --- Adaptation --- p.37 / Chapter 2.2.2.3. --- Tissue sampling --- p.38 / Chapter 2.2.2.4. --- Enzyme-linked immunosorbent assay (ELISA) --- p.38 / Chapter 2.2.2.4.1. --- Serum cortisol analysis --- p.39 / Chapter 2.2.2.4.2. --- Serum triiodothyronine analysis --- p.39 / Chapter 2.2.2.4.3. --- Serum thyroxine analysis --- p.39 / Chapter 2.2.2.5. --- Protein extraction and Protein quantification --- p.40 / Chapter 2.2.2.6. --- Protein gel electrophoresis and immunoblotting (Western blotting) --- p.40 / Chapter 2.2.2.7. --- RNA extraction --- p.41 / Chapter 2.2.2.8. --- Reverse transcription for first-strand cDNAs from total RNAs samples from liver --- p.42 / Chapter 2.2.2.9. --- Real-time quantitative PCR assays of IGF-I mRNA expression --- p.43 / Chapter 2.2.3. --- In vivo experiments involving cadmium injection --- p.44 / Chapter 2.2.3.1. --- Experimental animals --- p.44 / Chapter 2.2.3.2. --- Adaptation --- p.44 / Chapter 2.2.3.3. --- Tissue sampling --- p.45 / Chapter 2.2.3.4. --- Enzyme-linked immunosorbent assay (ELISA) --- p.45 / Chapter 2.2.3.4.1. --- Serum cortisol analysis --- p.45 / Chapter 2.2.3.4.2. --- Serum triiodothyronine analysis --- p.45 / Chapter 2.2.3.4.3. --- Serum thyroxine analysis --- p.46 / Chapter 2.2.3.5. --- Protein extraction and Protein quantification --- p.46 / Chapter 2.2.3.6. --- Protein gel electrophoresis and immunoblotting (Western blotting) --- p.46 / Chapter 2.2.3.7. --- RNA extraction --- p.46 / Chapter 2.2.3.8. --- Reverse transcription for the first-strand cDNAs from total RNAs samples from liver --- p.46 / Chapter 2.2.3.9. --- Real-time quantitative PCR of IGF-I mRNA expression --- p.46 / Chapter 2.2.4. --- In vitro part of the project (Primary cell culture: hepatocytes exposed to cadmium medium) --- p.47 / Chapter 2.2.4.1. --- Experimental animals --- p.47 / Chapter 2.2.4.2. --- Primary hepatocytes culture preparation --- p.47 / Chapter 2.2.4.3. --- Cadmium treatment and cell harvest --- p.48 / Chapter 2.2.4.4. --- "RNA extraction, reverse transcription for the first-strand cDNAs from total RNAs samples from lysed cells and real-time quantitative PCR of IGF-I mRNA expression" --- p.48 / Chapter 2.2.5. --- Statistical analysis --- p.48 / Chapter 2.3. --- Results --- p.49 / Chapter 2.3.1. --- Serum cortisol level --- p.49 / Chapter 2.3.2. --- Serum triiodothyronine level --- p.49 / Chapter 2.3.3. --- Serum thyroxine level --- p.49 / Chapter 2.3.4. --- Pituitary growth hormone level --- p.50 / Chapter 2.3.5. --- Hepatic insulin-like growth factor mRNA expression --- p.50 / Chapter 2.4. --- Discussion --- p.58 / Chapter 2.4.1. --- Serum cortisol level --- p.58 / Chapter 2.4.2. --- Thyroid hormones --- p.61 / Chapter 2.4.3. --- Growth hormone --- p.64 / Chapter 2.4.4. --- Insulin-like growth factor-I --- p.67 / Chapter 2.5. --- Conclusion --- p.70 / Chapter Chapter 3: --- "Effects of cadmium exposure on MT and G6PDH mRNA expressions of silver sea bream, Sparus sarba" --- p.71 / Chapter 3.1. --- Introduction --- p.72 / Chapter 3.2. --- Materials and methods --- p.74 / Chapter 3.2.1. --- Overall experimental design --- p.74 / Chapter 3.2.2. --- In vivo experiments involving exposure to waterborne cadmium --- p.74 / Chapter 3.2.2.1. --- Experimental animals --- p.74 / Chapter 3.2.2.2. --- Adaptation --- p.74 / Chapter 3.2.2.3. --- Tissue sampling --- p.74 / Chapter 3.2.2.4. --- RNA extraction --- p.74 / Chapter 3.2.2.5. --- Reverse transcription for first-strand cDNAs from total RNAs samples from gill and liver --- p.75 / Chapter 3.2.2.6. --- Amplification of partial fragments of metallothionein (MT) --- p.75 / Chapter 3.2.2.7. --- Rapid amplification of 5´ة and 3´ة cDNA ends of metallothionein (MT) --- p.76 / Chapter 3.2.2.7.1. --- Amplification of 5´ة cDNA end --- p.76 / Chapter 3.2.2.7.2. --- Amplification of 3´ة cDNA end --- p.78 / Chapter 3.2.2.8. --- Real-time quantitative PCR of MT and G6PDH mRNA expressions --- p.79 / Chapter 3.2.3. --- In vivo injection of cadmium --- p.80 / Chapter 3.2.3.1. --- "Experimental animals, adaptation and tissue sampling" --- p.80 / Chapter 3.2.3.2. --- RNA extraction --- p.80 / Chapter 3.2.3.3. --- Reverse transcription for first-strand cDNAs from total RNAs samples from gill and liver --- p.81 / Chapter 3.2.3.4. --- Real-time quantitative PCR of MT and G6PDH mRNA expression --- p.81 / Chapter 3.2.4. --- In vitro exposure of primary hepatocyte culture to cadmium --- p.81 / Chapter 3.2.4.1. --- Experimental animals --- p.81 / Chapter 3.2.4.2. --- Preparation of the hepatocytes for cell culture --- p.81 / Chapter 3.2.4.3. --- Cadmium treatment and cell harvest --- p.81 / Chapter 3.2.4.4. --- "RNA extraction, reverse transcription for first-strand cDNAs from total RNAs samples from lysed cells and real-time quantitative PCR of MT and G6PDH mRNA expression" --- p.82 / Chapter 3.2.5. --- Statistical analysis --- p.82 / Chapter 3.3. --- Results --- p.83 / Chapter 3.3.1. --- MT cloning and characterization --- p.83 / Chapter 3.3.2. --- Metallothionein mRNA expression --- p.83 / Chapter 3.3.3. --- Hepatic glucose-6-phosphate dehydrogenase mRNA expression --- p.84 / Chapter 3.4. --- Discussion --- p.91 / Chapter 3.4.1. --- MT cloning and characterization --- p.91 / Chapter 3.4.2. --- Metallothioneins mRNA expression --- p.92 / Chapter 3.4.3. --- Hepatic glucose-6-phosphate dehydrogenase mRNA expression --- p.95 / Chapter 3.5. --- Conclusion --- p.98 / General conclusion --- p.99 / References --- p.101

Devido à ampla utilização do cádmio nas indústrias, muitos solos encontram-se contaminados. Vários estudos com bioindicadores estão sendo realizados para detectar cádmio em solos, sendo a maioria com minhocas (Eisenia fetida) e plantas, contudo estes testes são laboriosos e longos. Os micro-organismos tem se mostrado uma alternativa promissora para esta aplicação, pois são de fácil cultivo e manutenção, além de apresentarem uma rápida resposta às alterações ambientais. Desta forma, o objetivo deste trabalho foi utilizar diferentes gêneros de leveduras como bioindicadores de cádmio no solo. Para tanto foram avaliadas dezoito linhagens de leveduras, das quais foram selecionadas três quanto à sensibilidade na presença de cádmio. A levedura Torulopsis utilis var. thermophilus (IZ214) apresentou alta sensibilidade, a Candida utilis (IZ300) sensibilidade mediana e Saccharomyces cerevisiae (Pedra) a menor sensibilidade. O crescimento foi avaliado por espectrometria, através de leituras de D.O. e pela técnica do Trifeniltetrazólio (TTC) para avaliação da viabilidade celular. O uso do TTC mostrouse mais adequado nos bioensaios com leveduras evidenciando as células metabolicamente ativas. Foi avaliado o crescimento das leveduras em extratos de solo com cádmio obtidos pelo extrator CaCl2 0,01 mol L-1. Observou-se que o crescimento das leveduras na maioria dos tratamentos foi igual ou superior ao controle. Isso ocorreu devido à adsorção do cádmio à matéria orgânica e outros elementos. Para comprovar a adsorção do cádmio à matéria orgânica, foi realizado ensaio com a levedura S. cerevisiae (Pedra) onde ao extrato de solo obtido foi adicionado solução de Cd2+. Através da leitura de D.O. foi observada uma taxa de inibição de 75% para 100 mg L-1 de cádmio e, pela técnica do TTC, a taxa de inibição de 100% ocorreu na concentração de 44 mg L-1. Ensaios com sementes foram realizados para avaliar a germinação e crescimento na presença de cádmio. Sementes de Cucumis sativus foram expostas à solução de Cd2+, ocorrendo 100% de germinação e apresentando DL50 de 7,33 mg L-1. Este resultado foi maior comparado aos obtidos para as leveduras avaliadas, as quais apresentaram uma DL50 de 0,89 mg L-1 para a levedura T. utilis (IZ214) e DL50 de 1,86 mg L-1 para a S. cerevisiae (Pedra). As sementes de Zea mays foram expostas ao extrato de solo com cádmio, onde foi obtido uma DL50 de 33,9 ± 3,0 mg L-1 e, nas mesmas condições para a levedura S. cerevisae (Pedra), a DL50 foi de 29,8 mg L-1. Os resultados obtidos mostraram uma proximidade de valores nos ensaios com extrato de solo com cádmio entre a semente de milho e levedura. Com isso, foi possível concluir que as leveduras são sensíveis ao cádmio e podem ser uma nova opção de bioindicadores. Além disso, as leveduras e principalmente a S. cerevisiae possuem um alto grau de homologia com os eucariotos superiores, permitindo assim o estudo de aspectos de toxicidade relevantes a biologia humana. / Due to extensive use of cadmium in industries, many soils are contaminated. Several studies are being conducted with biomarkers to detect cadmium in soils, mostly with earthworms (Eisenia fetida) and plants, however, these tests are laborious and lengthy. Micro-organisms have been presented as an alternative to this application, as they are easy to grow and maintain, and offer a rapid response to environmental changes. Thus, the aim of this study was to use different kinds of yeasts as indicators of cadmium in soil. Eighteen yeasts strains were evaluated, from which three were selected for their sensitivity in the presence of cadmium. The yeast Torulopsis utilis var. thermophilus (IZ214), showed high sensitivity, Candida utilis (IZ300), showed a median sensitivity and Saccharomyces cerevisiae (Ale Yeast) a showed lower sensitivity. Yeasts growth was assessed through spectrophotometry, by reading O.D. and by the technique Triphenyltetrazolium (TTC) to assess cell viability. The use of TTC was more appropriate as an indicator of cell viability in yeast bioassays showing metabolically active cells. We evaluated the growth of yeasts in soil extracts with cadmium obtained by extraction with CaCl2 0.01 mol L-1. It was observed that the growth of the yeast on most of the treatments was equal or superior to the control. This was due to the adsorption of cadmium to organic matter and other elements. To prove the adsorption of cadmium to organic matter, an essay was performed with the yeast S. cerevisiae (Ale Yeast), in which the soil extract solution obtained was added with Cd2+. By reading the O.D. it was observed an inhibition rate of 75% for 100 mg L- 1 cadmium and, by the TTC technique, the highest rate of 100% inhibition occurred at a concentration of 44 mg L-1. Seeds trials were conducted to evaluate germination and growth. Cucumis sativus seeds were exposed to a solution of Cd2+, resulting in 100% of germination and showing a LD50 of 7.33 mg L-1, which was greater than the one measured for yeasts, who had an LD50 of 0.89 mg L-1 to the yeast T. utilis (IZ214) and LD50 of 1.86 mg L-1 for S. cerevisiae (Ale Yeast). The seeds of Zea mays were exposed to soil extract containing cadmium, in which it was noticed a LD50 of 33.9 ± 3.0 mg L-1 and, by having the same conditions for the yeast S. cerevisiae (Ale Yeast), the LD50 was of 29.8 mg L-1. The results showed similar values in tests with soil extract with cadmium comparing the corn seed and the yeast. Thus, it was concluded that the yeasts are sensitive to cadmium and may be a new option bioindicators. Also, yeasts, in special S. cerevisiae, have a high degree of homology with higher eukaryotes, therefore allowing the study of relevant toxicity aspects in human biology.

This thesis describes an automatic Rinse Tank Control System used in detection and removal of contaminating agents from industrial plating rinse tanks. It automatically monitors the purity of the rinse water in sixteen separate rinse tanks, and permits fresh water to enter the tanks only when the conductivity of the rinse water in each tank exceeds a predetermined level. Its use will result in large savings in consumption of fresh water and the subsequent reduction in discharge of effluent to the treatment plants.

Thesis (Ph.D. (Biochemistry)) --University of Limpopo, 2010 / A heavy-metal resistant bacterium (GM 16) was isolated from a South African antimony mine, and the non-viable cells of the isolate were used to investigate its biosorption capacity for Cd(II) and Cu(II) from aqueous solution in a batch process. The biosorption of both metals were found to be influenced by factors such as pH of the metal solution, initial metal ion and biomass concentrations, rate of agitation, presence of other metal ions, contact time of the metal solution with the biomass and temperature. The initial biosorption of both Cd(II) and Cu(II) was rapid and equilibrium was reached within 1 hour of biomass contact with the metal solutions. The sorption of both metal ions was higher in weak acid than in strong acid conditions and the optimum pH values for Cd(II) and Cu(II) biosorption were 7 and 6, respectively. The presence of the other metal ions in the metal adsorption media influenced the biosorption of both Cd(II) and Cu(II). Mg2+ ions decreased the uptake of Cu(II) and Cd(II) by 4.7 and 6.5 %, respectively. Whereas K+, Na+ and Ca2+ ions increased the uptake of Cd(II) by 12.3, 8.7, and 3.2 %, respectively, they slightly decreased the sorption Cu(II) (2-6.4 %). Increases in initial metal ion (40-120 mg L-1) and biomass (0.8-4.8 g L-1) concentrations enhanced the sorption of Cd(II) and Cu(II) by GM16 biomass. When the biomass concentration was increased from 0.8 to 4.8 g L-1, the biosorption capacity of Cd(II) increased from 5.5 to 14.5 mg g-1 while that of Cu(II) increased from 2.8 to 14.7 mg g-1 at optimum pHs and a temperature of 40 °C. Maximum adsorption of both metals occurred at an agitation rate of 100 rpm. In addition, increase in initial metal ion concentration from 40-120 mg L-1 increased the initial adsorption rates (h) and the equilibrium metal sorption capacity (qe) of the GM 16 biomass from 6.07 to 16.51 mg g-1 for Cu(II) and 8.9 to 17.9 mg g g-1 for Cd(II). Adsorption equilibrium data for both metal ions fitted well to the Langmuir adsorption model with high correlation coefficients (r2 > 0.90) but the data for Cu(II) could also be described by the Freundlich adsorption model. Increase in temperature from 25-40 °C only caused marginal increases in maximum metal sorption capacities (qmax). The results on kinetic analysis showed that the biosorption processes of Cd(II) and Cu(II) ions by the non-viable GM 16 cells followed pseudo-second order kinetic model betterthan the pseudo-first order model, although the calculated metal sorption capacities obtained with the model were overestimated. The calculated thermodynamic parameters showed that the biosorption of Cd(II) and Cu(II) ions was feasible, spontaneous and slightly endothermic for Cd(II) but slightly exothermic for Cu(II) under examined conditions. Based on 16S ribosomal DNA sequencing, the bacterial isolate (GM 16) was identified as a Bacillus sp. and is closely related to Bacillus thuringiensis and Bacillus cereus strains. The biosorption capacity of the non-viable GM 16 biomass was higher than the biosorption capacity reported for the viable GM 16 cells, 65 % of Cd(II) was removed by non-viable biomass whereas 48 % was removed by the viable biomass. For the biosorption of Cu(II), the % metal ion adsorbed for the non-viable GM 16 cells was slightly higher than the % adsorbed for the viable cells although not statistically significant. Only 67 % of Cu(II) was removed by the non-viable cells whereas 65 % was removed by the viable cells. / National Research Foundation