Determinar o conteúdo dos lipídeos presentes nos tecidos animais nem sempre resulta em uma resposta com precisão, devido á pouca disponibilidade de métodos adequados para a extração e determinação quantitativa destes lipídeos. A extração de lipídeos de matrizes complexas, como o pescado, por meio dos métodos tradicionais de Bligh & Dyer e Folch normalmente utilizam solventes com elevada toxicidade, cujos resíduos podem gerar um elevado impacto ambiental. A chamada segurança química está diretamente ligada à qualidade de vida e alerta para as questões de controle e prevenção dos efeitos adversos dos solventes ao ser humano e ao ambiente, compreendendo desde a extração, uso e descarte desses e seus resíduos. Portanto, o objetivo deste trabalho foi estudar as condições de extração de lipídeos totais de resíduos do processamento de tilápias, visando à proposição de um método alternativo que garanta uma eficiência tão satisfatória quanto as obtidas pelos métodos tradicionais de extração. Ademais, foi desenvolvido um método de extração mais seguro ao ambiente utilizando solventes menos tóxicos que os propostos pelo método de Bligh &Dyer, por meio da aplicação experimental de um diagrama de fases hexano- etanol- água. Após a identificação da melhor combinação de solventes, os extratos obtidos com hexano- etanol apresentaram rendimento eficiente em lipídeos totais e capacidade de extrair os componentes lipídicos polares e apolares das amostras analisadas. O melhor aproveitamento dos lipídeos a serem extraídos da matriz resíduos de peixes na proporção em massa de solvente hexano: etanol: água, foram da solução 1 (1: 7: 1,375) para a carcaça, da solução 2 (1: 2,5: 1,1875) para a cabeça e da solução 4 (4: 1: 4,375) para as vísceras totalizando 14,13%, 14,69 e 47,63% de teor de lipídeos, respectivamente. Logo, ao buscar sistemas de solventes alternativos ao clorofórmio - metanol, para extrair lipídeos de resíduos do processamento de tilápias, foi possível identificar as melhores proporções de hexano: etanol: água como substituição do método tradicional proposto por Bligh & Dyer (1959). / The total lipid content of animal tissues is not always accurately measured due to the lack of adequate methods for lipid extraction and quantitative determination of tissue fat. The extraction of lipids from complex matrices, such as fish, using the traditional methods proposed by Bligh &Dyer and Folch usually, employs solvents with high toxicity, whose residues can generate a high environmental impact. The chemical safety concern nowadays is directly linked to quality of life involving control and prevention of adverse effects of solvents to humans and the environment, ranging from the extraction, use and disposal of these and their residues. Moreover, the procedures of sample preparation, the sample: solvent ratio, the proportion of solvents applied, and the order of addition of solvents during the experiment are not standardized in these methods. Therefore, the present study aimed to assess the extraction conditions of total lipids from fish processing residues, and thus propose a standardized method which ensures a maximum efficiency in lipid extraction. Furthermore, a more environmental-friendly oil extraction method using less toxic solvents than those proposed by the Bligh & Dyer method (i.e. using the hexane-ethanol-water phase diagram) was developed. After identifying the best combination of solvents, the extracts obtained with hexane- ethanol showed effective yield on total lipids and the ability to extract the polar lipid components and nonpolar of the samples. The best use of lipids to be extracted from fish waste matrix, were the solution 1 (1: 7: 1,375) for the carcass of solution 2 (1: 2,5: 1,1875) for the head and the solution 4 (4: 1: 4,375) for the viscera totaling 14,13%, 14,69% and 47,63%(4: 1: 4,375) respectively. Therefore, to seek alternative solvent systems chloroform - methanol to extract lipids of tilapia processing waste, it was possible to identify the best proportions of hexane: ethanol: water as replacing the traditional method proposed by Bligh & Dyer (1959).

O objetivo deste estudo foi avaliar as propriedades químicas, biológicas e antimicrobianas dos solventes endodônticos, Citrol, Eucaliptol, d-Limoneno, Xilol e Endosolv E. Dentre os testes químicos, foram avaliados a microdureza dentinária, onde utilizamos blocos de dentina bovina que foram expostos aos solventes por 2 períodos, 5 e 15 min e submetidos ao teste de microdureza. Outro teste químico foi a capacidade de dissolução dos materiais obturadores pelo teste de imersão nos solventes em 3 períodos, 2, 5 e 15 min. Para essa avaliação foram, confeccionados corpos de prova dos cimentos, AH Plus, Acroseal, Sealer 26, Endofill, MTA Fillapex e RealSeal SE e dos cones de guta-percha estandardizado Dentsply (DP), ProTaper e Resilon. Um terceiro teste, foi realizado para avaliar a capacidade de desobturação dos canais radiculares e o efeito da agitação ultrassônica dos solventes endodônticos após a desobturação. Sessenta incisivos centrais superiores foram divididos em 6 grupos sendo um para cada solvente (n=10) mais um grupo controle (solução fisiológica). Todos dentes foram instrumentados e obturados pela mesma técnica e escaneados no Micro-CT. Os dentes foram então desobturados utilizando ProTaper Retratamento/ProTaper Universal como técnica para todos grupos, associada a um dos solventes e foram escaneados novamente para a avaliação do volume de material remanescente após a desobturação. Cada um dos dentes foi desobturado e preenchido com o mesmo solvente utilizado na desobturação. Cada solvente foi agitado pelo ultrassom por 1 min e novamente foram escaneados e avaliados os volumes restantes dos materiais nos canais radiculares. Na avaliação biológica, utilizamos o teste de citotoxicidade com células de camundongo NIH-3T3 pelo ensaio MTT. As culturas celulares foram plaqueadas e submetidas aos solventes diluídos nas concentrações de 0.5 a 2.5%, e avaliados quanto à viabilidade celular. Por fim o último teste foi o antimicrobiano, avaliado pelo teste de contato direto em biofilme misto, formado in situ sobre blocos de dentina bovina. Os biofilmes foram expostos por 5 min a um dos solventes, corados com Live/Dead e avaliados em microscopia confocal de varredura a laser. Como resultados encontramos que todos solventes causaram alterações físicas na dentina e foram capazes de comprometer a microdureza dentinária, sendo que esta ação foi aumentada quando o tempo de contato foi maior. O Xilol e o Endosolv E foram mais efetivos na dissolução dos cimentos AH Plus e Endofill no período de 15 minutos em relação aos demais solventes. O Endosolv E apresentou capacidade de dissolução mais efetiva sobre os cones de guta-percha DP no período de 15 minutos em relação aos outros solventes estudados. Nos demais cimentos, materiais sólidos e nos outros períodos, os solventes apresentaram capacidade de dissolução semelhantes. Na avaliação do Micro-CT, todos solventes foram capaz de remover as obturações dos canais radiculares inclusive o grupo controle, porém nenhum foi capaz de remover os materiais obturadores completamente. A agitação ultrassônica dos solventes favoreceu um aumento na remoção do material obturador, porém não proporcionou a remoção completa do material. A agitação ultrassônica dos solventes removeu mais material obturador remanescente do que a agitação sem solvente (controle). No teste biológico todos solventes foram citotóxicos, no entanto somente o Xilol foi capaz de manter mais de 50% de células viáveis. E por fim, o Xilol e o Eucaliptol foram os solventes que apresentam a melhor ação antimicrobiana enquanto que o Citrol mostrou a pior. / The aim of this study was to evaluate the chemical, biological and antimicrobial properties of the Endodontic solvents, Citrol, Eucalyptol, d-Limonene, Xylene and Endosolv E. First chemical properties analysis were evaluated by dentin microhardness, where we used bovine dentin blocks that were exposed to the solvents in 2 periods, 5 and 15 min and subjected to the microhardness test. Second test was to evaluate the ability of endodontic solvents to dissolve root-filling materials by immersion test in, 2, 5 and 15 minutes. Specimens of sealers, AH Plus, Acroseal, Sealer 26, Endofill, MTA Fillapex an RealSeal SE and guttapercha Dentsply (DP), ProTaper and Resilon points were prepared and evaluated in the three periods. Next test was conducted to evaluate the ability of solvents to desobturate root canals filled and analyse the effect of the ultrasonic passive agitation of solvents after canal unfill procedure. Sixty maxillary central incisors were prepared and obturated by same technique and randomly divided into 6 groups, one for each solvent (n=10) and a control group (saline solution). Teeth were scanned in Microcomputed Tomography (Micro-CT), unfilled with ProTaper Retratament/Protaper Universal with one of the solvents and scanned again. The residual root-fillings volumes were analysed and all teeth root canal were filled with the same solvent used in unfilling process and were passive-ultrasonically agitated (PUl) for 1 min. All teeth were scanned again in Micro-CT and data were analysed. Biological properties assessments were evaluated by cytotoxicity test with NIH-3T3 mouse cells by MTT assay. Cell cultures were subjected to diluted solvents at concentrations of 0.5 to 2.5%, and cell viability were analysed. Last evaluation in our study was the antimicrobial test. A total of 60 bovine dentin specimens infected intraorally were exposed for 5 min in direct contact to one of the solvents evaluated. After that, the dentin blocks with biofilms were stained with Live/Dead and the proportions of dead and live bacteria assessed by Confocal Laser Scanning Microscopy were analysed. The results revealed that that all solvents caused physical changes in dentin and were able to compromise the dentin microhardness, and this action was increased when the contact time was higher. In the dissolving test, Xylene and Endosolv E were more effective to dissolve AH Plus sealers and Endofill in the 15 min period, compared to other solvents. The highest dissolution capacity of Endosolv E was observed on guttapercha cones DP also in the period of 15 minutes an this dissolving capacity was more effectively then other solvents. In all other root-fillings and gutta-percha and Resilon points and in other periods (2 and 5 min), the solvents showed similar dissolution capacity. In Micro-CT evaluation all solvents were able to remove the root canal filling materials, including saline solution, but none could remove it completely. Solvents PUl, showed an increase in root-filling material left from unfilling procedure, but also provided incomplete removal. When solvents were PUl, they removed the remaining materials significantly compared to control group (saline solution). In biological test all solvents showed high cytotoxicity, however only the Xylene was able to maintain more than 50% of viable cells. According to the antimicrobial evaluation, Xylene and Eucalyptol showed best antimicrobial action while the Citrol showed the worst.

Dióxido de carbono supercrítico (scCO2) é um solvente pouco eficiente para substâncias polares em geral. Uma maneira interessante de superar esta limitação e explorar todo o seu potencial como solvente verde, possível substituto para os solventes orgânicos voláteis comuns, é a introdução de tensoativos específicos para scCO2 no sistema. No presente trabalho, foram sintetizadas três novas séries de tensoativos oxigenados para scCO2. As moléculas possuem cabeças CO2-fóbicas mono e poli-hidroxiladas, em sua maioria à base de açúcares, e três tipos de cadeias CO2-fílicas, duas delas perfluoradas (-C7F15 e -C9F19) e uma peracetilada (derivada do ácido D-glucônico). Foram investigadas as suas solubilidades e comportamentos de fase em CO2 e em sistemas ternários (água-CO2-tensoativo), bem como a atividade na interface CO2-água. Todos eles dispersaram água em scCO2 com [água] / [tensoativo] (W) igual a 10, exibindo pressões de névoa comparáveis àquelas do sistema \"a seco\". Adicionalmente, os tensoativos reduziram a tensão interfacial CO2-água. O efeito das cabeças CO2-fóbicas e cadeias CO2-fílicas nessa redução pôde ser analisado separadamente. Os resultados dos experimentos de tensão interfacial dinâmica sugerem que tanto a difusão das moléculas da fase contínua para a subinterface, quanto a sua inserção e migração na interface contribuem para o decaimento das tensões interfaciais. / Supercritical carbon dioxide (scCO2) is a poor solvent for polar substances in general. An interesting way to overcome this limitation and fulfill its potential as a green solvent, a possible substitute for common volatile organic solvents, is the introduction of scCO2-suitable surfactants in the system. In the present work, three series of novel oxygenated surfactants for scCO2 were synthesized. The amphiphiles contain mono and poly-hydroxylated CO2-phobic heads, most of them sugar-based, as well as three types of CO2-philic tails, two of them perfluorinated (-C7F15 and -C9F19) and one peracetylated (D-gluconic acid derivative). Their solubilities and phase behaviors in CO2 and in ternary systems (water-CO2-surfactant), as well as their activities at the CO2-water interface, were investigated. All of them dispersed water in scCO2- with water-to-surfactant ratio (W) of 10, exhibiting cloud pressures comparable to those of \"dry\" systems. Also, the surfactants reduced the CO2-water interfacial tension. The effect of both the CO2-phobic heads and the CO2-philic tails could be analyzed separately. Dynamic interfacial tension results suggest that both diffusion from bulk CO2 to subinterface and insertion and migration of molecules within the interface contribute to the time-dependent decay of the interfacial tensions.

Introdução É importante o desenvolvimento de sistemas de controle de poluição do ar que sejam eficientes, além de aplicáveis à condição nacional e pra proteção da saúde humana, uma vez que os compostos do grupo BTEX são tóxicos. Objetivo - Avaliar o desempenho de sistema de tratamento biológico para vapores de BTEX e investigar as melhores condições de operação para os critérios de projeto adotados. Métodos. Trata-se de trabalho experimental com utilização de unidade piloto constituída de coluna de vidro (diâmetro interno de 80 mm e altura total de 1,2 m) tendo no seu interior um meio filtrante composto vegetal e anéis de Pall - que serviram de suporte para os microrganismos e onde se realizou a biodegradação. Foram monitorados parâmetros como temperatura, perda de carga, vazão, concentração dos gases na entrada e na saída, que constituíram a base para desenvolver intervenções e melhorar seu desempenho. A análise dos gases foi feita por fotoionização (PID) em aparelho portátil. Conclusões - Conclui-se que é viável o tratamento biológico para remoção do BTEX de efluentes gasosos, nas condições operacionais adotadas, com eficiência máxima de remoção em torno de 90 por cento . A máxima eficiência foi obtida para tempo de retenção de 2,4 min., carga superficial do gás de 11,9 m3/m2xh, carga mássica no leito de 67 g/m3xh e capacidade de eliminação de 4 g/m3xh. O uso de anéis de Pall misturados ao composto evitou que valores elevados de perda de carga. Foi relevante a participação da adsorção. A utilização de composto mostrou-se viável como alternativa para a biodegradação do BTEX, fortalecendo seu uso com essa prática ambiental / Introduction - It is important to develop control systems for air pollution that are efficient, applicable to the national condition and to the protection of human health, since the group BTEX compounds are toxic. Objective - To evaluate the performance of biological treatment system for BTEX vapors and investigate the best operating conditions for the design criteria adopted. Methods - This experimental work used a pilot plant consisting of a glass column (internal diameter 80 mm and height of 1.2 m) filled with a filter medium - compost and Pall rings - which supported microorganisms and where biodegradation was carried out. Parameters were monitored such as temperature, pressure drop, flow rate, gas concentration at the inlet and outlet, which formed the basis for developing interventions and improve their performance. The gas analysis was measured by photoionization (PID) in a portable device. Conclusions -. We conclude that it is feasible biological treatment for removal of BTEX emissions, operating in the adopted conditions, with maximum removal efficiency (ER) of around 90 per cent . The maximum efficiency was obtained for empty bed retention time (EBRT) of 2.4 min, surface loading (SL) of 11.9 m 3 /m 2 xh, concentration load (CL) g/m3xh 67 and elimination capacity (EC) of 4 g/m 3 xh. The use of Pall rings mixed with the compost prevented high levels of pressure drop. It is relevant the participation of adsorption process. The use of compost proved to be feasible as an alternative to the biodegradation of BTEX, strengthening its use in the environmental practice

Objetivo: Avaliar repercussões da exposição ocupacional a uma mistura de solventes orgânicos sobre o desempenho visual de um grupo de frentistas. Método: Foram aplicados testes de ordenamento e discriminação de matizes, campo visual e sensibilidade ao contraste espacial de luminância em 25 frentistas (20 homens, M=36,4 anos, DP=8,9) e 25 controles sem histórico de exposição crônica a solventes (10 homens, M=33,8 anos, DP=8,8). As concentrações metabólitos urinários de tolueno (M=0,3 g/g de creatinina; DP=0,16) e xileno (M=0,1 g/g de creatinina; DP=0,02) e o tempo de trabalho (M=9,6 anos; DP=6,2) foram utilizados como indicativos da exposição dos frentistas. Os participantes foram submetidos a exame oftalmológico, e quando necessário, corrigir a acuidade visual para 20/20. Todas as medidas foram realizadas monocularmente com um olho escolhido ao acaso, com exceção do Potencial Visual Evocado Multifocal (PVEmf) e da campimetria. Para avaliar a visão de cores, utilizamos o Lanthony D15-d e Cambridge Colour Test 2.0. Na campimetria estática automatizada foi utilizado o protocolo branco-branco 24-2 do aparelho Humphrey Field Analyzer II-750i. A atividade elétrica visual cortical foi avaliada com o sistema de PVEmf Veris Science 5.2.4, utilizando um estímulo de 60 setores. A sensibilidade ao contraste espacial de luminância foi avaliada no teste Metropsis, para grades senoidais em 7 frequências espaciais de 0,2 a 20,0 cpg. Resultados: Os escores do grupo de frentistas e do grupo controle foram comparados pelo teste Mann-Whitney U. No teste de discriminação de cores (CCT), houve diferença estatística significativa entre controles e frentistas para a área total da elipse (p<0,01), elipticidade (p<0,05) e limiares nos eixos protan, deutan e tritan (p<0,05). No D15d houve diferença significativa entre os 8 dois grupos (p<0,01). Os dados da campimetria apresentaram diferenças significativas entre os dois grupos para as excentricidades de 90, 150 e 210, além dos valores de MD e PSD (p<0,05). Dos três frentistas avaliados com o PVEmf, todos apresentaram uma diminuição significativa (p<0,05) da amplitude do sinal (em relação a dados normativos) em um mínimo de 30 setores do campo visual, resultado que não foi observado no grupo controle. Nos testes de visão de cores, foi encontrada uma correlação (Spearman) positiva e significativa entre o tempo de trabalho e os índices do Lanthony D15d (p=0,52; p<0,05) e os limiares no eixo deutan (p=0,59; p<0,05). Na campimetria, houve correlações negativas significativas com o tempo de trabalho para a área da Fóvea (p=-051; p<0,05), e para os anéis de 30 (p=-0,46; p<0,05), 90 (p=-0,46; p<0,05) e 150 (p=-0,46; p<0,05). Não foi encontrada correlação significativa entre a sensibilidade ao contraste e o tempo de trabalho. Conclusões: Os resultados mostram alterações amplas e difusas no processamento visual em decorrência da exposição crônica a solventes orgânicos / Purpose: To evaluate the outcome of chronic occupational exposure to a mixture of solvents on the visual system of a group of gas station workers. Methods: 25 gas station workers (20 male; M=36,4 years old, SD=8,9) and 25 controls (10 male; M=33,8 years old, DP=8,8) with no history of chronic exposure to solvents were tested for hue discrimination and arrangement, spatial contrast sensitivity, visual field and multifocal VEPs. Urinary concentrations of toluene (M=0,3g/g of creatinine; Sd=0,16) and xylene metabolites (M=0,1 g/g creatinine; SD=0), along with the time of work (M=9,6 years; SD=6,2) were used as indicators of the exposure. The participants were submitted to an ophthalmologic examination and corrected the visual acuity to 20/20 whenever needed. All measurements were monocular (eye randomly chosen) and only one eye was tested, except for Multifocal Visual Evoked Potential (mfVEP) and the automated perimetry. Color was evaluated with the Lanthony D15d and Cambridge Colour Test 2.0. Automatic static perimetry used the white-on-white 24-2 protocol of the Humphrey Field Analyzer II-750i. Visual field was also evaluated with the mfVEP system Veris Science 5.2.4. Contrast sensitivity was measured with Metropsis software, using sine wave gratings of 0,2; 0,5; 1,0; 2,0; 5,0; 10,0 and 20,0 cpd. Results: The results for the two groups were compared using the Mann-Whitney U test. In the color discrimination test, the groups were significantly different for the thresholds in the three confusion axis tested (p<0,05), area of the ellipse (p<0,01) and ellipticity (p<0,05). In the color arrangement test, the two groups were significantly different (p<0,01). The automated perimetry results were also significantly different between groups for the 90, 150 e 210 eccentricity rings (p<0,05) and the MD and PSD values (p<0,05). Only three of the workers were tested with the mfVEP so far. All three had at least 30 sectors in the visual field 10 with significant loss of amplitude in the response (p<0,05, when compared to normative data). This result was not observed in the control group. The Spearman correlation coefficient was used to look for significant correlations between time of work and visual performance. For color vision, we found significant positive correlation between time of work and indexes of the Lanthony D15d (p=0,52; p<0,05) and deutan axis thresholds (p=0,59; p<0,05) for the CCT test. The analysis of sensitivity in eccentricity rings of perimetry data showed significant negative correlation with the time of work for the Fovea (p=-051; p<0,05) and rings of 30 (p=-0,46; p<0,05), 90 (p=-0,46; p<0,05) e 150 (p=-0,46; p<0,05). The contrast sensitivity data was not significantly correlated with time of work. Conclusions: The results presented here suggest that chronic occupational exposure to organic solvents leads to changes in the visual system function even when the exposure is within occupational safety limits. The results also suggest that the visual changes are extensive and diffuse

Lee Nga Lan. / Thesis submitted in: June 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references. / Abstract also in Chinese. / Abstract --- p.i / Acknowledgment --- p.iii / Table of contents --- p.iv / List of tables --- p.viii / List of figures --- p.x / Glossary of abbreviations --- p.xi / Chapter CHAPTER 1. --- INTRODUCTION --- p.1 / Chapter CHAPTER 2. --- BACKGROUND --- p.3 / Chapter 2.1 --- OUTBREAKS OF SOLVENT INDUCED NEUROPATHY IN MAN --- p.3 / Chapter 2.2 --- WORLD-WIDE INVESTIGATIONS ON ORGANIC SOLVENTS HAZARDS --- p.5 / Chapter 2.3 --- HEALTH EEFECTS OF ORGANIC SOLVENTS --- p.8 / Chapter 2.3.1 --- Effects on the Nervous System --- p.9 / Chapter (a) --- Peripheral Nervous System / Chapter (b) --- Central Nervous System / Chapter 2.3.2 --- Other Effects --- p.13 / Chapter 2.4 --- METHODOLOGICAL ISSUES IN THE INVESTIGATION OF SOLVENT NEUROTOXICITY --- p.14 / Chapter 2.4.1 --- Study Design --- p.15 / Chapter 2.4.2 --- Exposure Measurements --- p.17 / Chapter 2.4.3 --- Outcome Effects Measurements --- p.18 / Chapter 2.5 --- UNSOLVED PROBLEMS IN THE STUDY OF SOLVENT NEUROTOXICITY --- p.20 / Chapter 2.6 --- ORGANIC SOLVENTS IN THE PRINTING INDUSTRY --- p.21 / Chapter 2.7 --- PRINTING METHODS --- p.25 / Chapter 2.8 --- OFFSET LITHOGRAPHY --- p.27 / Chapter 2.8.1 --- Principles of Offset Lithography --- p.28 / Chapter 2.8.2 --- Image Carriers for Offset Lithography --- p.29 / Chapter 2.8.3 --- Lithographic Presses --- p.32 / Chapter 2.8.4 --- Printing Process --- p.34 / Chapter CHAPTER 3. --- STUDY OBJECTIVES AND METHODS --- p.37 / Chapter 3.1 --- OBJECTIVES --- p.37 / Chapter 3.2 --- METHODS --- p.38 / Chapter 3.2.1 --- Study Population --- p.38 / Chapter 3.2.2 --- Visits --- p.41 / Chapter 3.2.3 --- Workers' Health Assessment --- p.42 / Chapter 3.2.4 --- Air Sampling --- p.44 / Chapter 3.2.5 --- Definition of Exposures --- p.48 / Chapter 3.3 --- DATA ANALYSIS --- p.49 / Chapter CHAPTER 4. --- RESULTS --- p.51 / Chapter 4.1 --- RESPONSE RATE --- p.51 / Chapter 4.2 --- CHARACTERISTICS OF THE STUDY POPULATION --- p.53 / Chapter 4.2.1 --- Printing Companies --- p.53 / Chapter 4.2.2 --- Study Subjects --- p.56 / Chapter 4.3 --- HEALTH PROBLEMS OF STUDY SUBJECTS --- p.60 / Chapter 4.3.1 --- Sick Leave --- p.60 / Chapter 4.3.2 --- Prevalence of Subjective Symptoms --- p.61 / Chapter 4.3.3 --- Mean Number of Symptoms --- p.64 / Chapter 4.4 --- AIR SAMPLING RESULTS --- p.66 / Chapter 4.4.1 --- Mean Concentration Levels of Solvents --- p.71 / Chapter 4.4.2 --- Mean Concentration Levels of Solvents by Printing Plants --- p.73 / Chapter 4.4.3 --- Mean Concentration Levels of Solvents by Locations --- p.75 / Chapter 4.5 --- EXPOSURE-RESPONSE RELATIONSHIPS BETWEEN ORGANIC SOLVENTS AND SYMPTOMS --- p.77 / Chapter 4.6 --- RISK FACTORS FOR SUBJECTIVE SYMPTOMS --- p.85 / Chapter CHAPTER 5. --- DISCUSSIONS --- p.90 / Chapter 5.1 --- RESPONSE RATE --- p.90 / Chapter 5.2 --- SOURCES OF BIAS --- p.91 / Chapter 5.3 --- STUDY SUBJECTS --- p.92 / Chapter 5.4 --- SOLVENT EXPOSURES --- p.93 / Chapter 5.4.1 --- Occupational Hygiene --- p.93 / Chapter 5.4.2 --- Exposure Classification --- p.95 / Chapter 5.4.3 --- Chemical Interaction --- p.98 / Chapter 5.5 --- HEALTH PROBLEMS --- p.99 / Chapter CHAPTER 6. --- CONCLUSION --- p.103 / REFERENCES --- p.105 / APPENDICES --- p.120 / Appendices A1 to A9: Newspaper reports on polyneuropathy induced by organic solvents in a Hong Kong printing factory --- p.120 / Appendix B: Telephone follow up form --- p.129 / Appendix C: Letter to the printing factory employer --- p.130 / Appendix D: Subjective symptom questionnaire for solvent workers --- p.131 / Appendix E: Questionnaire for exposed group workers --- p.132 / Appendix F: Questionnaire for non-exposed group workers --- p.140 / Appendix G: NIOSH Sampling and Analytical Method 1400 --- p.145 / Appendix H: NIOSH Sampling and Analytical Method 1500 --- p.150 / "Appendix I: Chemical Analytical Method from Department of Hygiene, School of Public Health, Sun Yat Sen University of Medical Sciences" --- p.157 / Appendix J: Air Sampling Worksheet --- p.159 / BIBLIOGRAPHY --- p.162

Song Hong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves ). / Abstracts in English and Chinese; questionnaire in Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.iv / Acknowledgments --- p.vi / Table of Contents --- p.vii / List of tables --- p.x / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Printing industry and organic solvents exposure --- p.1 / Chapter 1.2 --- Risk of low level exposures to organic solvents --- p.2 / Chapter 1.3 --- Using neurobehavioral methods to study the subclinical effects --- p.3 / Chapter Chapter 2 --- Literature review --- p.4 / Chapter 2.1 --- Organic solvents and neurobehavioral impairment --- p.4 / Chapter 2.2 --- Methodology of Neurobehavioral Test --- p.6 / Chapter 2.2.1 --- Criteria for selecting test battery --- p.7 / Chapter 2.2.2 --- Standardization of neurobehavioral test battery --- p.8 / Chapter 2.2.3 --- Reliability and validity --- p.9 / Chapter 2.2.4 --- Confounding factors of neurobehavioral test --- p.10 / Chapter 2.3 --- Neurobehavioral effects of different levels of solvent exposures --- p.12 / Chapter 2.3.1 --- Positive results in field studies --- p.12 / Chapter 2.3.2 --- Negative results in field studies --- p.17 / Chapter 2.3.3 --- Dose-response relationship in the field studies --- p.18 / Chapter 2.3.4 --- To separate acute and chronic effects --- p.20 / Chapter 2.3.5 --- The long-term effects of solvent exposure --- p.21 / Chapter 2.4 --- Limitations of these studies --- p.23 / Chapter 2.5 --- Summary --- p.26 / Chapter Chapter 3 --- Aims and Objectives --- p.31 / Chapter 3.1 --- Aims of the present research --- p.31 / Chapter 3.2 --- Position of this study cm this research domain --- p.32 / Chapter Chapter 4 --- Subjects and Method --- p.33 / Chapter 4.1 --- Study design --- p.33 / Chapter 4.2 --- Study population and sampling --- p.33 / Chapter 4.2.1 --- Participation --- p.33 / Chapter 4.2.2 --- Exposed group --- p.34 / Chapter 4.2.3 --- Reference group --- p.34 / Chapter 4.2.4 --- Sample size estimation --- p.34 / Chapter 4.3 --- Data collection --- p.36 / Chapter 4.3.1 --- Exposure assessment --- p.36 / Chapter 4.3.1.1 --- Air sample measurements --- p.36 / Chapter 4.3.1.2 --- Biological monitoring --- p.38 / Chapter 4.3.2. --- Medical assessment --- p.38 / Chapter 4.3.2.1 --- Pre-test questionnaire --- p.39 / Chapter 4.3.2.2 --- Neurobehavioral assessment --- p.39 / Chapter 4.4 --- Data Analysis --- p.43 / Chapter 4.4.1 --- Data Processing --- p.43 / Chapter 4.4.2 --- Statistical analysis --- p.44 / Chapter 4.4.2.1 --- Descriptive analysis --- p.44 / Chapter 4.4.2.2 --- Identifying the main confounding factories --- p.44 / Chapter 4.4.2.3 --- Comparing the tests score adjusted for confounding --- p.45 / Chapter 4.4.2.4 --- Dose-response analysis --- p.45 / Chapter Chapter 5 --- Results --- p.47 / Chapter 5.1 --- Demographic characteristics of the subjects --- p.47 / Chapter 5.2 --- Comparison of the basic characteristics between the exposed group and the reference group --- p.48 / Chapter 5.3 --- Comparison of the symptoms between the exposed group and the reference group --- p.49 / Chapter 5.4 --- Comparison of the scores of neurobehavioral tests between the exposed group and the reference group --- p.51 / Chapter 5.5 --- Identifying potential confounding of neurobehavioral test --- p.51 / Chapter 5.5.1 --- Main confounding factors of NCTB test on performance tests --- p.51 / Chapter 5.5.2 --- Main confounding factors of Profile of Mood States --- p.54 / Chapter 5.6 --- Groups comparison of the neurobehavioral effects --- p.57 / Chapter 5.6.1 --- Comparison of the adjusted mean scores between the exposed group and the reference group --- p.57 / Chapter 5.6.2 --- Groups comparison of the adjusted tests score in Factories C and G respectively --- p.58 / Chapter 5.7 --- Exposure assessment --- p.61 / Chapter 5.7.1 --- Air sampling results of the printing factories --- p.62 / Chapter 5.7.2 --- Relationship between results of active and passive sampling systems --- p.63 / Chapter 5.7.3 --- Biological monitoring --- p.63 / Chapter 5.8 --- Dose-response relationship --- p.65 / Chapter Chapter 6 --- Discussion --- p.69 / Chapter 6.1 --- Findings of this study --- p.69 / Chapter 6.1.1 --- Subjective symptoms --- p.69 / Chapter 6.1.2 --- Neurobehavioral effects --- p.70 / Chapter 6.1.3 --- Exposure intensity --- p.72 / Chapter 6.1.4. --- Dose-response relationship --- p.75 / Chapter 6.2 --- Applications of the study results --- p.76 / Chapter 6.2.1 --- The need for prevention measures --- p.77 / Chapter 6.2.2 --- Contributing to re-setting of OELs --- p.77 / Chapter 6.2.3. --- The evidence on neurotoxicology --- p.78 / Chapter 6.3 --- Limitations of the study --- p.79 / Chapter 6.3.1. --- Possibility of bias --- p.79 / Chapter 6.3.2. --- Lack of historical hygiene measurement data --- p.80 / Chapter 6.3.3. --- Influence of workshift --- p.81 / Chapter 6.3.4. --- Combined exposures to noise and organic solvents --- p.82 / Chapter 6.4 --- Conclusion --- p.83 / Appendices --- p.84 / Appendix 1 --- p.84 / Appendix 2 --- p.97 / Appendix 3 --- p.102 / Appendix 4 --- p.103 / Appendix 5 The Administration of The WHO-NCTB Tests --- p.114 / Test 1 Profile of Mood States Test --- p.115 / Test 2. Simple Reaction Time Test --- p.116 / Test 3. Digit Span Test Test --- p.119 / Test 4. Santa Ana Test --- p.120 / Test 5. Digit Symbol Test --- p.122 / Test 6. Benton Visual Retention Test --- p.123 / Test 7. Pursuit Aiming Test --- p.125 / Appendix 6 --- p.126 / Reference List --- p.127

Dióxido de carbono supercrítico (scCO2) é um solvente pouco eficiente para substâncias polares em geral. Uma maneira interessante de superar esta limitação e explorar todo o seu potencial como solvente verde, possível substituto para os solventes orgânicos voláteis comuns, é a introdução de tensoativos específicos para scCO2 no sistema. No presente trabalho, foram sintetizadas três novas séries de tensoativos oxigenados para scCO2. As moléculas possuem cabeças CO2-fóbicas mono e poli-hidroxiladas, em sua maioria à base de açúcares, e três tipos de cadeias CO2-fílicas, duas delas perfluoradas (-C7F15 e -C9F19) e uma peracetilada (derivada do ácido D-glucônico). Foram investigadas as suas solubilidades e comportamentos de fase em CO2 e em sistemas ternários (água-CO2-tensoativo), bem como a atividade na interface CO2-água. Todos eles dispersaram água em scCO2 com [água] / [tensoativo] (W) igual a 10, exibindo pressões de névoa comparáveis àquelas do sistema \"a seco\". Adicionalmente, os tensoativos reduziram a tensão interfacial CO2-água. O efeito das cabeças CO2-fóbicas e cadeias CO2-fílicas nessa redução pôde ser analisado separadamente. Os resultados dos experimentos de tensão interfacial dinâmica sugerem que tanto a difusão das moléculas da fase contínua para a subinterface, quanto a sua inserção e migração na interface contribuem para o decaimento das tensões interfaciais. / Supercritical carbon dioxide (scCO2) is a poor solvent for polar substances in general. An interesting way to overcome this limitation and fulfill its potential as a green solvent, a possible substitute for common volatile organic solvents, is the introduction of scCO2-suitable surfactants in the system. In the present work, three series of novel oxygenated surfactants for scCO2 were synthesized. The amphiphiles contain mono and poly-hydroxylated CO2-phobic heads, most of them sugar-based, as well as three types of CO2-philic tails, two of them perfluorinated (-C7F15 and -C9F19) and one peracetylated (D-gluconic acid derivative). Their solubilities and phase behaviors in CO2 and in ternary systems (water-CO2-surfactant), as well as their activities at the CO2-water interface, were investigated. All of them dispersed water in scCO2- with water-to-surfactant ratio (W) of 10, exhibiting cloud pressures comparable to those of \"dry\" systems. Also, the surfactants reduced the CO2-water interfacial tension. The effect of both the CO2-phobic heads and the CO2-philic tails could be analyzed separately. Dynamic interfacial tension results suggest that both diffusion from bulk CO2 to subinterface and insertion and migration of molecules within the interface contribute to the time-dependent decay of the interfacial tensions.

Le but de notre projet était d’établir un procédé éco-compatible pour la synthèse de composés possédant une activité antioxydante. Le choix des molécules cibles s’est porté sur des glycosylflavonols. Plutôt que d’effectuer une synthèse totale des composés existant dans la nature, difficilement isolés, et montrant une activité intéressante, nous avons choisi de préparer une nouvelle classe de molécules dont les éléments structuraux nécessaires à l’activité antioxydante sont maintenus mais présentent un lien glycosidique facile à réaliser. Chaque étape de la synthèse a été conçue et réalisée en suivant les principes de la chimie verte. Nous avons donc favorisé les réactions à l’économie d’atomes élevée, évité l’utilisation de groupements protecteurs et utilisé des solvants verts : polyéthylène glycol, eau, éthanol. La stratégie mise en place s’appuie sur une synthèse convergente. D’une part le motif sucre est synthétisé sous forme d’un C-glycoside afin d’augmenter sa stabilité par rapport à des conditions d’hydrolyse chimique ou enzymatique. D’autre part la synthèse de différentes polyhydroxychalcones par une nouvelle méthode ne nécessitant pas de groupements protecteurs a permis d’obtenir différents motifs flavonoïdes. Le lien entre le motif sucre et les motifs flavonoïdes a ensuite été établi en utilisant la réaction de cycloaddition catalysée par le cuivre (I) entre un azoture et un alcyne. Cette réaction a par ailleurs été l’objet d’une étude qui a montré que le polyéthylène glycol est un solvant de choix pour cette réaction puisqu’il permet notamment de réduire la contamination des produits de synthèse par le cuivre.Ainsi deux glycosylflavonols et quatre mélanges glycosylchalcone-glycosylflavanone ont été synthétisés en milieu éco-compatible et sans groupement protecteur. De plus, les réactions et les étapes de purification ont été optimisées afin de réduire la quantité de déchets générés au cours du procédé. Enfin, l’évaluation par les métriques de la chimie verte a été effectuée pour chaque étape de synthèse ainsi que pour la globalité du procédé. / The aim of this project was to develop an eco-friendly process for the synthesis of compounds endowed with antioxidant activity. The target molecules were glycosylflavonols. Instead of performing a total synthesis of natural compounds, difficult to isolate, and showing an interesting activity, we decided to prepare a new class of molecules in which the structural elements necessary for antioxidant activity are maintained but having a glycosidic linkage easy to achieve.Each step of the synthesis was designed and carried out following the principles of green chemistry. We have promoted reactions with a high atom economy, avoided the use of protecting groups and used polyethylene glycol, water, and ethanol as green solvents. The strategy was based on a convergent synthesis. Firstly, sugar moiety was synthesized as a C-glycoside to increase its stability with respect to conditions of chemical or enzymatic hydrolysis. On the other hand, the synthesis of different polyhydroxychalcones by a new method that does not require protecting groups yielded different flavonoid moieties. The link between the sugar moiety and flavonoids moieties was then achieved using the copper-catalyzed azide-alkyne cycloaddition (CuAAC). This reaction has also been the subject of a study that showed that polyethylene glycol is a solvent of choice for this reaction, since it allowed reducing the copper contamination of the products.Two glycosylflavonols and four mixtures of glycosylchalcone-glycosylflavanone were synthesized in eco-friendly solvents without the use of protecting groups. Furthermore, reactions and purification steps were optimized to reduce the amount of waste generated during the process. Finally, the evaluation by green chemistry metrics was performed for each step of the synthesis as well as for the whole process.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-02-12T13:39:06Z No. of bitstreams: 2 Tese - Leonardo Bruno Assis Oliveira - 2015.pdf: 2535407 bytes, checksum: 9ceeaccfc6fcaae7855e1a6bba20b039 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-02-16T06:45:17Z (GMT) No. of bitstreams: 2 Tese - Leonardo Bruno Assis Oliveira - 2015.pdf: 2535407 bytes, checksum: 9ceeaccfc6fcaae7855e1a6bba20b039 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-02-16T06:45:17Z (GMT). No. of bitstreams: 2 Tese - Leonardo Bruno Assis Oliveira - 2015.pdf: 2535407 bytes, checksum: 9ceeaccfc6fcaae7855e1a6bba20b039 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-10-02 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / We present in this work a theoretical study of structural and spectroscopic properties of vitamin E models in chloroform and water solutions, of eumelanin oligomers in water and also of eumelanin constituents in mixtures of methanol and water. The in uence of solvent e ects in molecular properties was included using an iterative process based on sequential methodology Monte Carlo/Quantum Mechanics. Optical absorption spectra were obtained from TD-DFT calculations with B3LYP, PBE1PBE, BHandHLYP and CAMB3LYP functionals whereas the magnetic shielding constants were calculated employing the gauge-including atomic orbital (GIAO) approach through B3LYP functional. We analyze four homologous forms of vitamin E models, which di er in the number and position of methyl groups on the chromanol ring. The inclusion of solvent e ects in the rst electronic transition indicates solvatochromic shifts ranging between 1 and 3 nm in chloroform, and between 7 and 11 nm in water. The results also show that these e ects on the magnetic shielding constants (13C) and (17O) are small, but an appropriate description of the solvent shift for (17O) of the hydroxyl group in water requires the inclusion of explicit molecules that make hydrogen bonds. Our results for the chemical shifts (13C) of the carbon atoms of the chromanol ring in chloroform solution are in good agreement with the experimental results, although overestimated between 3 and 9 ppm. The analysis of the con gurations obtained from Monte Carlo simulations shows that for eumelanin oligomers of increasing size, monomers, dimers, tetramers and a layer, there is an increase in the average total number of hydrogen bonds. Solvent e ects are particularly relevant for the NMR spectroscopy of nitrogen and oxygen atoms. The shielding constant (17O) may change up to 98% for the monomers, when we consider the presence of explicit water molecules, and up to 41% for the tetramers from calculations with ASEC (Average Solvent Eletrostatic Con guration). In general, the oligomerization of eumelanin constituents extends the region of the electromagnetic spectrum which occurs the optical absorption and also shows a shift of the absorption peak of the HOMO!LUMO transitions for longer wavelength regions. We also present a superposition of the absorption spectra of eumelanin constituents that shows the trend of experimental results. We select some eumelanin constituents to analyze the e ects of mixtures of methanol and water on the spectroscopic properties. The results indicate that the concentration of water in the mixture can in uence the magnetic shielding constants of more electronegative atoms, as well as the position of the absorption spectrum peaks. The results show that the values of can present variations up to 34% while the location of the absorption peak can change up to 73 nm in going from pure methanol to pure water. We also analyze the distribution of the methanol and water molecules around the eumelanin constituents studied in order to determine the preferential solvation. / Apresentamos neste trabalho um estudo te órico das propriedades eletrônicas, estruturais e espectrosc opicas (1) de modelos de vitamina E em solu ções de clorof ormio e água, (2) de constituintes da eumelanina em solução de água e (3) tamb em de algumas dessas mol éculas da eumelanina em misturas de metanol e água. A inuência dos efeitos de solvente nas propriedades de interesse foi inclu da com simulações cl ássicas num processo iterativo baseado na metodologia sequencial Monte Carlo/Mecânica Quântica. Os espectros de absor ção óptica foram obtidos a partir de c álculos TD-DFT com os funcionais B3LYP, PBE1PBE, BHandHLYP e CAM-B3LYP em fase isolada e em solu ção de água e as constantes de blindagem magn ética foram calculadas com a aproxima ção GIAO (Gauge-Included Atomic Orbitals) e o funcional B3LYP. Analisamos quatro formas hom ologas que modelam a vitamina E, as quais diferem entre si no n úmero e na posição dos grupos metil no anel cromanol. A inclusão dos efeitos de solvente na primeira transi ção eletrônica indica desvios solvatocrômicos variando entre 1 e 3 nm em clorof ormio, e entre 7 e 11 nm para a água. Os resultados tamb em mostram que esses efeitos nas constantes de blindagem magn etica (13C) e (17O) são pequenos, mas uma descri ção apropriada do deslocamento de solvente para a constante de blindagem para o (17O) do grupo hidroxila em agua requer a inclusão de mol eculas expl citas que realizam liga ções de hidrogênio. Nossos resultados para os desvios qu micos (13C) para os atomos de carbono do anel cromanol em solu ção de clorof ormio estão em bom acordo com os resultados experimentais, embora superestimados entre 3 e 9 ppm. Para as mol eculas constituintes da eumelanina, selecionamos quatro monômeros para formar dois d meros, dois tetrâmeros e um layer. A an alise das con gura ções obtidas com o ASEC mostra que o processo de oligomeriza ção leva a um aumento do n umero total m edio das liga ções de hidrogênio. A presen ça do solvente e particularmente relevante para a espectroscopia de NMR dos atomos de nitrogênio e oxigênio. As constantes de blindagem (17O) podem sofrer altera ções de at e 98% para os monômeros, quando consideramos a inclusão de mol éculas expl citas de água, e de at e 41% para os tetrâmeros a partir de c alculos com o ASEC (Con gura ção Eletrost atica M edia do Solvente). De modo geral, a oligomeriza ção amplia a região do espectro eletromagn etico onde ocorre a absor ção óptica para os prov aveis constituintes da eumelanina e tamb em mostra um deslocamento do pico de absor ção da transi ção HOMO!LUMO para regiões de maiores comprimentos de onda. Mostramos tamb em que a superposição dos espectros de absorção das mol eculas que compõem cada um dos tetrâmeros reproduz a tendência dos resultados obtidos experimentalmente para a mol ecula de melanina. Selecionamos algumas mol eculas da eumelanina para analisar os efeitos das misturas de metanol e agua nas suas propriedades espectrosc opicas. Os resultados indicam que a concentração de agua na mistura pode in uenciar as constantes de blindagem magn etica de atomos mais eletronegativos, assim como a posi c~ao dos picos do espectro de absor c~ao. Dependendo da mol ecula, os valores de podem sofrer varia c~ao de at e 34% enquanto a localiza c~ao do pico de absor c~ao pode mudar em at e 73 nm quando passamos do metanol puro para a agua pura. Analisamos tamb em a distribui c~ao dos dois tipos de solvente ao redor das mol eculas estudadas com o intuito de determinar a solvata c~ao preferencial tendo em vista a natureza das intera c~oes envolvidas: soluto-solvente e solvente-solvente.