A non-reactive model system comprising a highly concentrated and unstable oil-in-water emulsion was used to investigate the retention of oil by the membrane in producing biodiesel with a membrane reactor. Critical flux was identified using the relationship between the permeate flux and transmembrane pressure along with the separation efficiency of the membrane. It was shown that separation efficiencies above 99.5% could be obtained at all operating conditions up to the critical flux. It was observed that the concentration of oil in all collected permeate samples using the oil-water system was below 0.2 wt% when operating at a flux below the critical flux. Studies to date have been limited to the characterization of low concentrated emulsions below 15 vol.%. The average oil droplet size in highly concentrated emulsions was measured as 3200 nm employing direct light scattering (DLS) measurement methods. It was observed that the estimated cake layer thickness of 20 to 80 mm was larger than external diameter of the membrane tube i.e. 6 mm based on a large particle size. Settling of the concentrated emulsion permitted the detection of a smaller particle size distribution (30-100 nm) within the larger particles averaging 3200 nm. It was identified that DLS methods could not efficiently give the droplet size distribution of the oil in the emulsion since large particles interfered with the detection of smaller particles. The content of the smaller particles represented 1% of the total weight of oil at 30°C and 5% at 70°C. This was too low to be detected using DLS measurements but was sufficient to affect ultrafiltration. In order to study the critical flux in the presence of transesterification reaction and the effect of cross flow velocity on separation, various oils were transesterified in another membrane reactor providing higher cross flow velocity. higher cross flow velocity provides better separation by reducing materials deposition on the surface of the membrane due to higher shearing. The oils tested were canola, corn, sunflower and unrefined soy oils (Free Fatty Acids (FFA< 1%)), and waste cooking oil (FFA= 9%). The quality of all biodiesel samples was studied in terms of glycerine, mono-glyceride, di-glyceride and tri-glyceride concentrations. The composition of all biodiesel samples were in the range required by ASTM D6751 and EN 14214 standards. A critical flux based on operating pressure in the reactor was reached for waste cooking and pre-treated corn oils. It was identified that the reaction residence time in the reactor was an extremely important design parameter affecting the operating pressure in the reactor. / Natural Sciences and Engineering Research Council of Canada (NSERC)

A non-reactive model system comprising a highly concentrated and unstable oil-in-water emulsion was used to investigate the retention of oil by the membrane in producing biodiesel with a membrane reactor. Critical flux was identified using the relationship between the permeate flux and transmembrane pressure along with the separation efficiency of the membrane. It was shown that separation efficiencies above 99.5% could be obtained at all operating conditions up to the critical flux. It was observed that the concentration of oil in all collected permeate samples using the oil-water system was below 0.2 wt% when operating at a flux below the critical flux. Studies to date have been limited to the characterization of low concentrated emulsions below 15 vol.%. The average oil droplet size in highly concentrated emulsions was measured as 3200 nm employing direct light scattering (DLS) measurement methods. It was observed that the estimated cake layer thickness of 20 to 80 mm was larger than external diameter of the membrane tube i.e. 6 mm based on a large particle size. Settling of the concentrated emulsion permitted the detection of a smaller particle size distribution (30-100 nm) within the larger particles averaging 3200 nm. It was identified that DLS methods could not efficiently give the droplet size distribution of the oil in the emulsion since large particles interfered with the detection of smaller particles. The content of the smaller particles represented 1% of the total weight of oil at 30°C and 5% at 70°C. This was too low to be detected using DLS measurements but was sufficient to affect ultrafiltration. In order to study the critical flux in the presence of transesterification reaction and the effect of cross flow velocity on separation, various oils were transesterified in another membrane reactor providing higher cross flow velocity. higher cross flow velocity provides better separation by reducing materials deposition on the surface of the membrane due to higher shearing. The oils tested were canola, corn, sunflower and unrefined soy oils (Free Fatty Acids (FFA< 1%)), and waste cooking oil (FFA= 9%). The quality of all biodiesel samples was studied in terms of glycerine, mono-glyceride, di-glyceride and tri-glyceride concentrations. The composition of all biodiesel samples were in the range required by ASTM D6751 and EN 14214 standards. A critical flux based on operating pressure in the reactor was reached for waste cooking and pre-treated corn oils. It was identified that the reaction residence time in the reactor was an extremely important design parameter affecting the operating pressure in the reactor. / Natural Sciences and Engineering Research Council of Canada (NSERC)

Cancer is a leading cause of death that affects millions of people across the globe each year. Photodynamic therapy (PDT) is a relatively new treatment approach for cancer in which anticancer drugs are activated by light at an appropriate wavelength to generate highly cytotoxic reactive oxygen species (ROS) and achieve tumor destruction. Compared with conventional chemo- and radiotherapy, PDT can be performed with minimal invasiveness, local targeting and reduced side effects. However, most of the currently available PDT drugs mainly absorb in the visible part of the spectrum, where light penetration depth into human tissues is very limited. Therefore, increasing the treatment depth of PDT has been considered to be an important approach to improve the effectiveness of PDT for treating larger and thicker tumor masses. In this thesis, we present our investigation into the potential of two-photon activated PDT (2-γ PDT), combination therapy of PDT and chemotherapy, and bioluminescence-activated PDT as a means to increase the treatment depth of this modality. In 2-γ PDT, the photosensitizing agents are activated through simultaneous absorption of two photons. This approach allows the use of near-infrared (NIR) light that can penetrate deeper into tissues and thus, has the potential of treating deep-seated tumors and reducing side effects, while the non-linear nature of two-photon excitation (TPE) may improve tumor targeting. We have evaluated the PDT efficacy of a second-generation photosensitizer derived from chlorophyll a, pyropheophorbide a methyl ester (MPPa), through both one- and two-photon activation. We observed that MPPa had high one-photon (1-γ PDT efficacy against both cisplatin-sensitive human cervical (HeLa) and cisplatin-resistant human lung (A549) and ovarian (NIH:OVCAR-3) cancer cells when activated by femtosecond (fs) laser pulses at 674 nm. At a low light dose of 0.06 J cm-2, the MPPa concentration required to produce a 50% cell killing effect (IC50) was determined to be 5.3 ± 0.3, 3.4 ± 0.3 and 3.6 ± 0.4 μM in HeLa, A549 and NIH:OVCAR-3 cells, respectively. More significantly, we also found that MPPa could be effectively activated at the optimal tissue-penetrating wavelength of 800 nm through TPE. At a light dose of 886 J cm-2, where no measurable photodamage was observed in the absence of MPPa, the IC50 values were measured to be 4.1 ± 0.3, 9.6 ± 1.0 and 1.6 ± 0.3 μM in HeLa, A549 and NIH:OVCAR-3 cells, respectively. We obtained corresponding LD50 (the light dose required to produce a 50% killing effect) values of 576 ± 13, 478 ± 18 and 360 ± 16 J cm-2 for 10 μM MPPa, which were approximately 3-5 times lower than the published 2-γ LD50 of Visudyne® and 20-30 times lower than that of Photofrin®. These results indicate that MPPa may serve as a photosensitizer for both 1- and 2-γ activated PDT treatment of difficult-to-treat tumors by conventional therapies. Indocyanine green (ICG), a dye having an absorption maximum near 800 nm, has been considered to be a potential NIR PDT agent. However, the PDT efficacy of ICG has been found to be very limited probably due to the low yield of cytotoxic ROS. In the present work, we have evaluated the combination effects of ICG-mediated PDT with conventional chemotherapy mediated by two types of chemotherapeutic drugs, namely the type II topoisomerase (TOPII) poisons etoposide (VP-16)/teniposide (VM-26) and the platinum-based drugs cisplatin (CDDP)/oxaliplatin (OXP). Synergistic enhancement of cytotoxicity and increased yields of DNA double strand breaks (DSBs) were observed in HeLa, A549 and NIH:OVCAR-3 cancer cells treated with the combination of ICG-PDT and VP-16. The presence of VP-16 during the laser irradiation process was found to be critical for producing a synergistic effect. An electron-transfer-based mechanism, in which ICG could increase the yield of highly cytotoxic VP-16 metabolites, was proposed for the observed synergistic effects, although direct spectroscopic detection of the reaction products was found to be very challenging. Moreover, we observed a much lower degree of synergy in the human normal fibroblast GM05757 cells than that in the three cancer cell lines investigated. Synergistic effects were also observed in A549 cells treated with the combination of ICG-PDT and VM-26 (i.e. an analog of VP-16). Furthermore, the combination of low-dose CDDP/OXP and ICG-PDT was demonstrated to produce an additive or synergistic effect in selected cancer cell lines. These preliminary results suggest that the combination of ICG-PDT with VP-16/VM-26 or CDDP/OXP chemotherapy may offer the advantages of enhancing the therapeutic effectiveness of ICG-PDT and lowering the side effects associated with the chemotherapeutic drugs. Bioluminescence, the generation of light in living organisms through chemical reactions, has been explored as an internal light source for PDT in recent years. This approach, in principle, does not suffer from the limited tissue penetration depth of light. In the present project, we have evaluated the effectiveness of luminol bioluminescence in activating the porphyrin photosensitizers meso-tetra(4-sulfonatophenyl)porphine dihydrochloride (TPPS4) and Fe(III) meso-tetra(4-sulfonatophenyl)porphine chloride (FeTPPS). The combination treatment induced significant killing of HeLa cells, while additive effects were observed in two normal human fibroblast cell lines (GM05757 and MRC-5). Our observations indicate that bioluminescence of luminol may generate sufficient light for intracellular activation of PDT sensitizers. Furthermore, the combination treatment may have intrinsic selectivity towards cancerous tissues. In summary, we have demonstrated effective killing of cancer cells by MPPa-mediated 1- and 2-γ PDT, combination of ICG-PDT and VP-16/VM-26 or CDDP/OXP chemotherapy, and bioluminescence of luminol activated PDT mediated by TPPS4/FeTPPS. These positive preliminary results indicate that all these three approaches have the potential of increasing the treatment depth of PDT and facilitating the development of more effective PDT treatment strategies.

A non-reactive model system comprising a highly concentrated and unstable oil-in-water emulsion was used to investigate the retention of oil by the membrane in producing biodiesel with a membrane reactor. Critical flux was identified using the relationship between the permeate flux and transmembrane pressure along with the separation efficiency of the membrane. It was shown that separation efficiencies above 99.5% could be obtained at all operating conditions up to the critical flux. It was observed that the concentration of oil in all collected permeate samples using the oil-water system was below 0.2 wt% when operating at a flux below the critical flux. Studies to date have been limited to the characterization of low concentrated emulsions below 15 vol.%. The average oil droplet size in highly concentrated emulsions was measured as 3200 nm employing direct light scattering (DLS) measurement methods. It was observed that the estimated cake layer thickness of 20 to 80 mm was larger than external diameter of the membrane tube i.e. 6 mm based on a large particle size. Settling of the concentrated emulsion permitted the detection of a smaller particle size distribution (30-100 nm) within the larger particles averaging 3200 nm. It was identified that DLS methods could not efficiently give the droplet size distribution of the oil in the emulsion since large particles interfered with the detection of smaller particles. The content of the smaller particles represented 1% of the total weight of oil at 30°C and 5% at 70°C. This was too low to be detected using DLS measurements but was sufficient to affect ultrafiltration. In order to study the critical flux in the presence of transesterification reaction and the effect of cross flow velocity on separation, various oils were transesterified in another membrane reactor providing higher cross flow velocity. higher cross flow velocity provides better separation by reducing materials deposition on the surface of the membrane due to higher shearing. The oils tested were canola, corn, sunflower and unrefined soy oils (Free Fatty Acids (FFA< 1%)), and waste cooking oil (FFA= 9%). The quality of all biodiesel samples was studied in terms of glycerine, mono-glyceride, di-glyceride and tri-glyceride concentrations. The composition of all biodiesel samples were in the range required by ASTM D6751 and EN 14214 standards. A critical flux based on operating pressure in the reactor was reached for waste cooking and pre-treated corn oils. It was identified that the reaction residence time in the reactor was an extremely important design parameter affecting the operating pressure in the reactor. / Natural Sciences and Engineering Research Council of Canada (NSERC)

Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2018-03-05T14:14:06Z No. of bitstreams: 1 JÚLIA GONÇALVES MAYER.pdf: 2883327 bytes, checksum: 6ae955490e1664e27d2c9669ad07a02c (MD5) / Made available in DSpace on 2018-03-05T14:14:06Z (GMT). No. of bitstreams: 1 JÚLIA GONÇALVES MAYER.pdf: 2883327 bytes, checksum: 6ae955490e1664e27d2c9669ad07a02c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os métodos analíticos utilizados para medir o percentual de ácido graxo trans (AGT) em alimentos envolvem cromatografia em fase gasosa com detecção de ionização de chama (CG-DIC), espectrometria de massas (CG-EM) e espectroscopia no infravermelho com transformada de Fourier e refletância total atenuada (FT-IR-ATR). O presente estudo teve como objetivo investigar a viabilidade e a aplicabilidade do uso das técnicas de FT-IR-ATR, sem extração, com extração prévia da gordura e após hidrólise e metilação dos ácidos graxos, para avaliar o conteúdo de AGT em biscoitos recheados e comparar os resultados obtidos com os encontrados para a determinação de ácido elaídico pela técnica de CG-EM. Foram escolhidas 9 marcas de biscoitos recheados sabor chocolate e 1 pacote de gordura vegetal hidrogenada, para ser usada como padrão secundário para análise de AGT por FT-IR-ATR. As amostras foram analisadas, inicialmente, quanto aos seus conteúdos de umidade e lipídeos totais. Para todas as amostras não foi observada concentração de umidade superior a 6,03 g/100 g. Os lipídeos totais variaram de 12,51±0,58 a 23,84±0,09 g/100 g. A presença de AGT foi identificada por FT-IR-ATR pela visualização da banda próxima a 966 cm−1 e confirmada com adição de padrão às amostras. Ao analisar as amostras de biscoito homogeneizadas e sem outro preparo, não foi viável a utilização do método de FT-IR-ATR, visto que a absorção de radiação infravermelha de substâncias da amostra se sobrepõe à absorção na região das ligações duplas trans, o que demonstra que a matriz do alimento pode influenciar na análise. Quanto a presença dos AGT, ácido elaídico (C18:1, n-9 trans) foi identificado e confirmado em todas as amostras através de CG-EM. Ao comparar a quantificação pelos métodos CG-EM e FT-IR-ATR em amostras de extratos e na forma de ácidos graxos metilados (FAME), foram observadas concentrações baixas de ácido elaídico/ácidos graxos trans (de 0,03±0,01 a 0,86±0,01 g/100 g de biscoito) obtidas pelos diferentes métodos. Não foram encontradas diferenças significativas entre as concentrações de AGT determinadas pelos três métodos testados para oito das nove amostras analisadas. O presente trabalho mostrou que a técnica de FT-IR-ATR, analisando o extrato lipídico e as amostras em forma de FAME foi adequado para estimar os teores de AGT em biscoito recheado de chocolate, visto que proporciona uma análise mais rápida, com um menor número de etapas e menor consumo de reagentes em relação às análises por CG-EM / The analytical methods used to measure the percentage of trans fatty acids in foods involve gas chromatography with flame ionization detection (GC-FID), mass spectrometry (GC-MS) and attenuated total reflectance fourier transform infrared spectroscopy (ATR-FT-IR). The aim of the present study was to investigate the feasibility and applicability of ATR-FT-IR techniques, without extraction, with previous extraction of fat and after hydrolysis and methylation of fatty acids to evaluate the content of TFA in filled biscuits, and compare the results obtained with those found for the determination of elaidic acid by the CG-MS technique. Were chosen 9 marks of chocolate filled biscuit and 1 packet of hydrogenated vegetable fat to be used as a secondary standard for AGT analysis by ATR-FT-IR. The samples were initially analyzed for their moisture contents and total lipids. For all samples, no moisture content higher than 6.03 g/100 g. Total lipids ranged from 12.51 ± 0.58 to 23.84 ± 0.09 g/100g. The presence of TFA was identified by ATR-FT-IR through the visualization of the band near 966 cm−1 and confirmed with addition of standard to the samples. When analyzing the homogenized cookie samples and without further preparation, the use of the ATR-FT-IR method was not feasible because the absorption of infrared radiation from sample substances overlaps the absorption in the region of the trans double bonds, which demonstrates that the food matrix may influence the analysis. Regarding the presence of TFA, elaidic acid (C18: 1, n-9 trans) was identified and confirmed in all samples by GC-MS. When comparing quantification by GC-MS and ATR-FT-IR in samples of extracts and in the form of fatty acids methly esters (FAME), low concentrations of elaidic acid / trans fatty acids were observed (0.03 ± 0.01 to 0.86 ± 0.01 g / 100 g of biscuit) obtained by the different methods. No significant differences were found between the concentrations of TFA determined by the three methods tested for eight of the nine samples analyzed. The present study showed that the ATR-FT-IR technique, analyzing the lipid extract and the samples in the form of FAME, was adequate to estimate the TFA contents in chocolate filled biscuit, because it provides a faster analysis with a smaller number of steps and lower toxic chemicals in relation to GC-MS analyzes

A non-reactive model system comprising a highly concentrated and unstable oil-in-water emulsion was used to investigate the retention of oil by the membrane in producing biodiesel with a membrane reactor. Critical flux was identified using the relationship between the permeate flux and transmembrane pressure along with the separation efficiency of the membrane. It was shown that separation efficiencies above 99.5% could be obtained at all operating conditions up to the critical flux. It was observed that the concentration of oil in all collected permeate samples using the oil-water system was below 0.2 wt% when operating at a flux below the critical flux. Studies to date have been limited to the characterization of low concentrated emulsions below 15 vol.%. The average oil droplet size in highly concentrated emulsions was measured as 3200 nm employing direct light scattering (DLS) measurement methods. It was observed that the estimated cake layer thickness of 20 to 80 mm was larger than external diameter of the membrane tube i.e. 6 mm based on a large particle size. Settling of the concentrated emulsion permitted the detection of a smaller particle size distribution (30-100 nm) within the larger particles averaging 3200 nm. It was identified that DLS methods could not efficiently give the droplet size distribution of the oil in the emulsion since large particles interfered with the detection of smaller particles. The content of the smaller particles represented 1% of the total weight of oil at 30°C and 5% at 70°C. This was too low to be detected using DLS measurements but was sufficient to affect ultrafiltration. In order to study the critical flux in the presence of transesterification reaction and the effect of cross flow velocity on separation, various oils were transesterified in another membrane reactor providing higher cross flow velocity. higher cross flow velocity provides better separation by reducing materials deposition on the surface of the membrane due to higher shearing. The oils tested were canola, corn, sunflower and unrefined soy oils (Free Fatty Acids (FFA< 1%)), and waste cooking oil (FFA= 9%). The quality of all biodiesel samples was studied in terms of glycerine, mono-glyceride, di-glyceride and tri-glyceride concentrations. The composition of all biodiesel samples were in the range required by ASTM D6751 and EN 14214 standards. A critical flux based on operating pressure in the reactor was reached for waste cooking and pre-treated corn oils. It was identified that the reaction residence time in the reactor was an extremely important design parameter affecting the operating pressure in the reactor. / Natural Sciences and Engineering Research Council of Canada (NSERC)