Computational modeling of light-matter interactions is a valuable approach for simulating photon paths in highly scattering media such as biological tissues. Monte Carlo (MC) models are considered to be the gold standard of implementation and can offer insights into light flux, absorption, and emission through tissues. Monte Carlo modeling is a computationally intensive approach, but this burden has been alleviated in recent years due to the parallelizable nature of the algorithm and the recent implementation of graphics processing unit (GPU) acceleration. Despite impressive translational applications, the relatively recent emergence of GPU-based acceleration of MC models can still be utilized to address some pressing challenges in biomedical optics beyond DOT and PDT. The overarching goal of the current dissertation is to advance the applications and abilities of GPU accelerated MC models to include low-cost devices and model Raman scattering phenomena as they relate to clinical diagnoses. The massive increase in computational capacity afforded by GPU acceleration dramatically reduces the time necessary to model and optimize optical detection systems over a wide range of real-world scenarios. Specifically, the development of simplified optical devices to meet diagnostic challenges in low-resource settings is an emerging area of interest in which the use of MC modeling to better inform device design has not yet been widely reported. In this dissertation, GPU accelerated MC modeling is utilized to guide the development of a mobile phone-based approach for diagnosing neonatal jaundice. Increased computational capacity makes the incorporation of less common optical phenomena such as Raman scattering feasible in realistic time frames. Previous Raman scattering MC models were simplistic by necessity. As a result, it was either challenging or impractical to adequately include model parameters relevant to guiding clinical translation. This dissertation develops a Raman scattering MC model and validates it in biological tissues. The high computational capacity of a GPU-accelerated model can be used to dramatically decrease the model’s grid size and potentially provide an understanding of measured signals in Raman spectroscopy that span multiple orders of magnitude in spatial scale. In this dissertation, a GPU-accelerated Raman scattering MC model is used to inform clinical measurements of millimeter-scale bulk tissue specimens based on Raman microscopy images. The current study further develops the MC model as a tool for designing diffuse detection systems and expands the ability to use the MC model in Raman scattering in biological tissues. / Bioengineering

ABSTRACT Erythema is a well-documented early indicator of tissue injury resulting from exposure to high doses of ionizing radiation. Close monitoring of radiation-induced injury to the skin can help identify opportunities for early interventions that may prevent or reduce more severe reactions. The gold standard for monitoring erythema is visual assessment (VA) by a trained clinician. This method has been criticized for being subjective and designed with very broad categorical descriptors. This work introduces a newly developed VA scale called the clinician erythema assessment for radiation therapy (CEA-RT).The reliability and accuracy of the CEA-RT scale was tested among 20 radiation therapists who trained to use the scale on digital images of radiation induced erythema. CEA-RT demonstrated to be highly reliable when therapist’s grades were compared to themselves, but moderately accurate when therapist’s grades were compared to each. A follow-up study with real patients and fewer but more extensively trained raters was proposed to demonstrate the grading accuracy of the CEA-RT scale. As an alternatively to VA, spectroscopy has the ability to monitor erythema by measuring the change in concentration of hemoglobin (Hb) within the vessels of the skin. These changes in Hb concentration are linked to the degree of erythema. This thesis also investigated the use of hyperspectral imaging (HSI) and diffuse reflectance spectroscopy (DRS) as potential technological alternatives for evaluating erythema. In a second study, Erythema was artificially induced in 3 volunteers who participated in a pilot study designed to assess the ability of an experimental HSI camera to detect skin changes. The data extracted from the hyperspectral images was found to effectively yield spectral profiles and Dawson’s erythema indices (EI) in agreement with the erythema grades assigned by the gold standard therefore showing HSI to be a viable alternative of assessing erythema. Finally, a third study compared DRS measurements to VA using the CEA-RT scale. The DRS system was previously used to measure in vivo erythema but did not compare spectral measurements to an accepted standard. Ten patient volunteers received daily DRS and VA evaluations for a period of 2 to 4 weeks. The results demonstrated that the Dawson’s EI calculated from the spectral data correlated well with the gold standard (VA grades) and that DRS is able to detect changes in the skin throughout the course of radiation treatments. / Thesis / Master of Science (MSc)

O dióxido de titânio, TiO2, é o pigmento branco mais importante na indústria de tintas devido à sua capacidade de refletir o espectro da radiação solar nas regiões do visível e do infravermelho. Ao refletir os comprimentos de onda da região do visível, o observador percebe a cor branca. A região do infravermelho é percebida pelo ser humano na forma de calor e a radiação ao ser refletida pelo pigmento diminui o aquecimento da superfície pintada. Neste trabalho foram investigados os aspectos morfológicos do TiO2 e avaliado o seu impacto nas propriedades ópticas de tintas base água. Quatro tipos de TiO2 foram utilizados, um de tamanho nanométrico, dois pigmentos comercias com diferentes tamanhos de partículas e o quarto obtido da calcinação do pigmento nanométrico. A calcinação objetivou a alteração da estrutura cristalina da fase anatase para rutilo do TiO2 nanométrico. Os pigmentos e carga (CaCO3) utilizados foram caracterizados através de análises morfológicas (tamanho e formato das partículas, estrutura cristalina, área superficial), absorção de óleo e espectroscopia de refletância difusa (regiões do ultravioleta, visível e infravermelho próximo). Foram produzidas tintas com diferentes teores de pigmentos (5%, 10%, 15% e 20%) As tintas foram caracterizadas através dos seguintes ensaios: viscosidade, espessura do filme seco, determinação de cor e brilho e espectroscopia de refletância difusa. Constatou-se que as propriedades ópticas das tintas são fortemente dependentes do tamanho de partícula do pigmento TiO2. A refletância da região do visível (400 a 700 nm) apresentou valores ótimos nas tintas produzidas com 15 e 20% dos pigmentos comerciais com tamanho médio de partícula entre 140 e 600 nm, produzindo um filme branco com elevada opacidade. A tinta com TiO2 nanométrico (15 a 60 nm para as partículas unitárias) apresentou baixos valores de refletância difusa nas regiões do visível e do infravermelho. As tintas produzidas com TiO2 calcinado, com elevado tamanho de partícula, refletiram mais eficientemente a região do infravermelho (700 – 2500 nm). O tratamento térmico do TiO2 nanométrico resultou num pigmento com tamanho de partícula adequado para aplicação de tintas reflexivas ao calor. / Titanium dioxide, TiO2, is the most important white pigment in coating industry due to its ability to reflect solar radiation spectrum in visible and infrared regions. When TiO2 reflects the light wavelengths in the visible region, the observer perceives the white color. The infrared region is perceived by human being in the form of heat and when the radiation is reflected by pigment decreases the heating of painted surface. In this work, the morphological aspects of TiO2 were investigated and evaluated their impact on optical properties of waterborne paints. Four types of TiO2 were used; one nanosized pigment, two commercial pigments with different particle sizes and the last one was obtained from the calcination of nanoparticles pigments. The main objective of calcination was to alter the crystalline structure of anatase phase to rutile phase of nanometric TiO2. The pigments and filler used (CaCO3) were characterized by morphological analysis (particle size distribution and shape analysis, crystalline structure, surface area), oil absorption and diffuse reflectance spectroscopy (ultraviolet, visible and near-infrared regions) Paints were prepared using different pigments concentrations (5%, 10%, 15% and 20%). The followings tests were carried out to characterize the paints: viscosity, dry film thickness, color and brightness determination and diffuse reflectance spectroscopy. It was observed that the optical properties of the paints are strongly dependent on TiO2 pigment particle size. The reflectance of the visible region (400 to 700 nm) showed better results in the paints produced with 15% and 20% of commercial pigment whose average particle size ranges were between 140 and 600 nm, producing a white film with high opacity. The paint with nanosized TiO2 showed lowest values of diffuse reflectance in visible and infrared regions. The paints formulated with calcined TiO2, pigment showing higher particle sizes, reflected more efficiently the infrared region (700 to 2500 nm). Thermal treatment of nanometric TiO2 resulted in a pigment with particle size suitable for application of heat reflective paints.

Quantification of blood fraction (fblood), blood oxygenation (S<img src="http://onlinelibrary.wiley.com/store/10.1002/jbio.201200055/asset/equation/tex2gif-inf-2.gif?v=1&amp;t=h70man4a&amp;s=4a6d004ec608a2a6ec8e8597f73bdb6be30286e8" />), melanin, lipofuscin and oxidised and reduced Cytochrome aa 3 and c was done from diffuse reflectance spectra captured in cortex, white matter, globus pallidus internus (GPi) and subthalamus during stereotactic implantations of 29 deep brain stimulation (DBS) electrodes with the aim of investigating whether the chromophores can give physiological information about the targets for DBS. Double-sided Mann-Whitney U -tests showed more lipofuscin in GPi compared to white matter and subthalamus (p &lt; 0.05). Compared to the other structures, fbloodwas significantly higher in cortex (p &lt; 0.05) and S<img src="http://onlinelibrary.wiley.com/store/10.1002/jbio.201200055/asset/equation/tex2gif-inf-4.gif?v=1&amp;t=h70man4c&amp;s=855c70105e88a292de25618487573dfc7d30e08a" /> lower in GPi (p &lt; 0.05). Median values and range for fblood were 1.0 [0.2–6.0]% in the cortex, 0.3 [0.1–8.2]% in white matter, 0.2 [0.1–0.8]% in the GPi and 0.2 [0.1–11.7]% in the subthalamus. Corresponding values for S<img src="http://onlinelibrary.wiley.com/store/10.1002/jbio.201200055/asset/equation/tex2gif-inf-6.gif?v=1&amp;t=h70man4e&amp;s=151ec25bee7270bcfc2292e70d6f4aea18348dbc" /> was 20 [0–81]% in the cortex, 29 [0–78]% in white matter, 0 [0–0]% in the GPi and 0 [0–92]% in the subthalamus. In conclusion, the measurements indicate very low oxygenation and blood volume for DBS patients, especially in the GPi. It would be of great interest to investigate whether this is due to the disease, the normal situation or an artefact of doing invasive measurements.

O dióxido de titânio, TiO2, é o pigmento branco mais importante na indústria de tintas devido à sua capacidade de refletir o espectro da radiação solar nas regiões do visível e do infravermelho. Ao refletir os comprimentos de onda da região do visível, o observador percebe a cor branca. A região do infravermelho é percebida pelo ser humano na forma de calor e a radiação ao ser refletida pelo pigmento diminui o aquecimento da superfície pintada. Neste trabalho foram investigados os aspectos morfológicos do TiO2 e avaliado o seu impacto nas propriedades ópticas de tintas base água. Quatro tipos de TiO2 foram utilizados, um de tamanho nanométrico, dois pigmentos comercias com diferentes tamanhos de partículas e o quarto obtido da calcinação do pigmento nanométrico. A calcinação objetivou a alteração da estrutura cristalina da fase anatase para rutilo do TiO2 nanométrico. Os pigmentos e carga (CaCO3) utilizados foram caracterizados através de análises morfológicas (tamanho e formato das partículas, estrutura cristalina, área superficial), absorção de óleo e espectroscopia de refletância difusa (regiões do ultravioleta, visível e infravermelho próximo). Foram produzidas tintas com diferentes teores de pigmentos (5%, 10%, 15% e 20%) As tintas foram caracterizadas através dos seguintes ensaios: viscosidade, espessura do filme seco, determinação de cor e brilho e espectroscopia de refletância difusa. Constatou-se que as propriedades ópticas das tintas são fortemente dependentes do tamanho de partícula do pigmento TiO2. A refletância da região do visível (400 a 700 nm) apresentou valores ótimos nas tintas produzidas com 15 e 20% dos pigmentos comerciais com tamanho médio de partícula entre 140 e 600 nm, produzindo um filme branco com elevada opacidade. A tinta com TiO2 nanométrico (15 a 60 nm para as partículas unitárias) apresentou baixos valores de refletância difusa nas regiões do visível e do infravermelho. As tintas produzidas com TiO2 calcinado, com elevado tamanho de partícula, refletiram mais eficientemente a região do infravermelho (700 – 2500 nm). O tratamento térmico do TiO2 nanométrico resultou num pigmento com tamanho de partícula adequado para aplicação de tintas reflexivas ao calor. / Titanium dioxide, TiO2, is the most important white pigment in coating industry due to its ability to reflect solar radiation spectrum in visible and infrared regions. When TiO2 reflects the light wavelengths in the visible region, the observer perceives the white color. The infrared region is perceived by human being in the form of heat and when the radiation is reflected by pigment decreases the heating of painted surface. In this work, the morphological aspects of TiO2 were investigated and evaluated their impact on optical properties of waterborne paints. Four types of TiO2 were used; one nanosized pigment, two commercial pigments with different particle sizes and the last one was obtained from the calcination of nanoparticles pigments. The main objective of calcination was to alter the crystalline structure of anatase phase to rutile phase of nanometric TiO2. The pigments and filler used (CaCO3) were characterized by morphological analysis (particle size distribution and shape analysis, crystalline structure, surface area), oil absorption and diffuse reflectance spectroscopy (ultraviolet, visible and near-infrared regions) Paints were prepared using different pigments concentrations (5%, 10%, 15% and 20%). The followings tests were carried out to characterize the paints: viscosity, dry film thickness, color and brightness determination and diffuse reflectance spectroscopy. It was observed that the optical properties of the paints are strongly dependent on TiO2 pigment particle size. The reflectance of the visible region (400 to 700 nm) showed better results in the paints produced with 15% and 20% of commercial pigment whose average particle size ranges were between 140 and 600 nm, producing a white film with high opacity. The paint with nanosized TiO2 showed lowest values of diffuse reflectance in visible and infrared regions. The paints formulated with calcined TiO2, pigment showing higher particle sizes, reflected more efficiently the infrared region (700 to 2500 nm). Thermal treatment of nanometric TiO2 resulted in a pigment with particle size suitable for application of heat reflective paints.

Submitted by DANILO ALMEIDA BALDO DO CARMO (danilo_baldo@hotmail.com) on 2018-05-23T15:53:30Z No. of bitstreams: 1 Tese_DaniloBaldo.pdf: 4225878 bytes, checksum: f6162ae37b5db55be022b39f8669ba7e (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-05-23T16:34:17Z (GMT) No. of bitstreams: 1 carmo_dab_dr_jabo.pdf: 4225878 bytes, checksum: f6162ae37b5db55be022b39f8669ba7e (MD5) / Made available in DSpace on 2018-05-23T16:34:17Z (GMT). No. of bitstreams: 1 carmo_dab_dr_jabo.pdf: 4225878 bytes, checksum: f6162ae37b5db55be022b39f8669ba7e (MD5) Previous issue date: 2018-04-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A agricultura moderna no contexto internacional propõe inovações para o agronegócio, em especial para as práticas agrícolas. No entanto, este avanço deverá auxiliar o empresário rural a aumentar a eficiência, utilizando de forma sustentável os recursos naturais: água, terra e energia. Desse modo, objetivou-se, neste estudo, verificar o potencial dos sensores para obter os dados espectrais de um argissolo com cultivo de café. Utilizou-se de um conjunto de dados de um grid com 51 amostras de solo, em 39 hectares, com cultivo de café (Catuaí Amarelo, linhagem IAC 62). A obtenção das variáveis da cor: matiz, valor, croma, red, green e blue foi determinada por espectroscopia de reflectância difusa (ERD) e sensor próximo móbile (SPM). Os resultados mostraram relação com os atributos do solo nos seguintes casos: redSPM e argila: (R2 = 0,70, p < 0,01), greenSPM e CTC (R2 = 0,73, p < 0,01), redSPM e P (R2 = 0,64, p < 0,05), blueSPM e EC (R2 = 0,96, p < 0,01) e, greenSPM e Fe (R2 = 0,75, p < 0,01). Para os atributos da planta, foram: greenSPM e P17 (R2 = 0,70, p < 0,01), defeitos com regressões variando de 0,71 - 0,84 e, redSPM e produtividade (R2 = 0,95, p < 0,01). Os resultados mostraram que o uso da cor determinada pelo red, green e blue permitiu identificar atributos do solo e áreas com potenciais produtivos e qualitativos do café. Para o estudo no Planalto Ocidental Paulista, realizou-se um grid em área de 13 milhões de hectares, totalizando 600 amostras na profundidade de 0,00-0,20 metros. Nestas amostras, foram determinadas as variáveis da cor. Observou-se semelhança no uso dos métodos ERD e SPM. Os semivariogramas da ERD tiveram alcance para as variáveis matiz, valor, croma, red, green e blue de 112 km, 216 km, 19 km, 207 km, 183 km e 158 km, respectivamente. Com o uso do SPM, os alcances foram de: 19 km, 226 km, 30 km, 160 km, 218 km e 75 km, respectivamente. Os semivariogramas cruzados estimaram os atributos físico-químicos (Argila, capacidade de troca catiônica - CTC, fósforo - P e hematita - Hm). Os semivariogramas cruzados explicaram a distância máxima de correlação observada entre as variáveis. Os resultados do SPM mostraram que a cor nos sistemas red, green e blue pode ser utilizada na predição do teor de argila (77%), CTC (99%), P (90%) e Hm (70%). Com o uso da ERD, os sistemas red, green e blue predizem o teor de argila (79%), CTC (94%), P (86%) e Hm (67%). Estes resultados mostram que a cor é um indicativo seguro dos atributos do solo. Como alternativa de baixo custo, o SPM mostrou ser uma ferramenta eficiente que possibilita a avaliação destes atributos. / Modern agriculture in the international context proposes innovations for agribusiness, especially for agricultural practices. However, this progress must help the rural entrepreneur to increase efficiency, using sustainable natural resources: water, land and energy. Thus, the objective of this study was, to verify the potential of the sensors to obtain the spectral data of an argisol with coffee cultivation. We used a set of data with a grid 51 soil samples on 39 hectares, with coffee cultivation (Yellow Catuaí, lineage IAC 62). Obtaining the color variables: hue, value, chroma, red, green and blue was determined by diffuse reflectance spectroscopy (DRS) and mobile near sensor (MNS). The results were related to soil attributes in the following cases: redMNS and clay: (R2 = 0.70, p <0.01), greenMNS and CTC (R2 = 0.73, p <0.01), redMNS and P (R2 = 0.64, p <0.05), blueMNS and EC (R2 = 0.96, p <0.01) and, greenMNS and Fe (R2 = 0.75, p <0.01). For the plant atributes, were: greenMNS and P17 (R2 = 0.70, p <0.01), defects with regressions ranging from 0.71 - 0.84 and, redMNS and productivity (R2 = 0.95, p <0.01). The results showed that the use of the color determined by red, green and blue allowed to identify soil attributes and areas with productive and qualitative potentials of coffee. For the study in the Midwest Paulista Plateau, a grid was realized in an area of 13 million hectares, totaling 600 samples in the depth of 0.00-0.20 meters. In these samples, the color variables were determined. Similarity was observed in the use of DRS and MNS methods. The DRS semivariograms were range for the hue, value, chroma, red, green and blue variables of 112 km, 216 km, 19 km, 207 km, 183 km and 158 km, respectively. With the use of MNS, the ranges were: 19 km, 226 km, 30 km, 160 km, 218 km and 75 km, respectively. The crossed semivariograms estimated the physical-chemical attributes (clay, cation exchange capacity - CTC, phosphorus - P and hematite-Hm). Crossed semivariograms explained the maximum correlation distance observed between the variables. The results of the MNS showed that the color in the red, green and blue systems can be used to predict the content of clay (77%), CTC (99%), P (90%) and Hm (70%). With the use of DRS, red, green and blue systems predict the content of clay (79%), CTC (94%), P (86%) and Hm (67%). These results show that color is a safe indication of soil attributes. As an alternative of low cost, the MNS has shown to be an efficient tool that allows the evaluation of these attributes.

O dióxido de titânio, TiO2, é o pigmento branco mais importante na indústria de tintas devido à sua capacidade de refletir o espectro da radiação solar nas regiões do visível e do infravermelho. Ao refletir os comprimentos de onda da região do visível, o observador percebe a cor branca. A região do infravermelho é percebida pelo ser humano na forma de calor e a radiação ao ser refletida pelo pigmento diminui o aquecimento da superfície pintada. Neste trabalho foram investigados os aspectos morfológicos do TiO2 e avaliado o seu impacto nas propriedades ópticas de tintas base água. Quatro tipos de TiO2 foram utilizados, um de tamanho nanométrico, dois pigmentos comercias com diferentes tamanhos de partículas e o quarto obtido da calcinação do pigmento nanométrico. A calcinação objetivou a alteração da estrutura cristalina da fase anatase para rutilo do TiO2 nanométrico. Os pigmentos e carga (CaCO3) utilizados foram caracterizados através de análises morfológicas (tamanho e formato das partículas, estrutura cristalina, área superficial), absorção de óleo e espectroscopia de refletância difusa (regiões do ultravioleta, visível e infravermelho próximo). Foram produzidas tintas com diferentes teores de pigmentos (5%, 10%, 15% e 20%) As tintas foram caracterizadas através dos seguintes ensaios: viscosidade, espessura do filme seco, determinação de cor e brilho e espectroscopia de refletância difusa. Constatou-se que as propriedades ópticas das tintas são fortemente dependentes do tamanho de partícula do pigmento TiO2. A refletância da região do visível (400 a 700 nm) apresentou valores ótimos nas tintas produzidas com 15 e 20% dos pigmentos comerciais com tamanho médio de partícula entre 140 e 600 nm, produzindo um filme branco com elevada opacidade. A tinta com TiO2 nanométrico (15 a 60 nm para as partículas unitárias) apresentou baixos valores de refletância difusa nas regiões do visível e do infravermelho. As tintas produzidas com TiO2 calcinado, com elevado tamanho de partícula, refletiram mais eficientemente a região do infravermelho (700 – 2500 nm). O tratamento térmico do TiO2 nanométrico resultou num pigmento com tamanho de partícula adequado para aplicação de tintas reflexivas ao calor. / Titanium dioxide, TiO2, is the most important white pigment in coating industry due to its ability to reflect solar radiation spectrum in visible and infrared regions. When TiO2 reflects the light wavelengths in the visible region, the observer perceives the white color. The infrared region is perceived by human being in the form of heat and when the radiation is reflected by pigment decreases the heating of painted surface. In this work, the morphological aspects of TiO2 were investigated and evaluated their impact on optical properties of waterborne paints. Four types of TiO2 were used; one nanosized pigment, two commercial pigments with different particle sizes and the last one was obtained from the calcination of nanoparticles pigments. The main objective of calcination was to alter the crystalline structure of anatase phase to rutile phase of nanometric TiO2. The pigments and filler used (CaCO3) were characterized by morphological analysis (particle size distribution and shape analysis, crystalline structure, surface area), oil absorption and diffuse reflectance spectroscopy (ultraviolet, visible and near-infrared regions) Paints were prepared using different pigments concentrations (5%, 10%, 15% and 20%). The followings tests were carried out to characterize the paints: viscosity, dry film thickness, color and brightness determination and diffuse reflectance spectroscopy. It was observed that the optical properties of the paints are strongly dependent on TiO2 pigment particle size. The reflectance of the visible region (400 to 700 nm) showed better results in the paints produced with 15% and 20% of commercial pigment whose average particle size ranges were between 140 and 600 nm, producing a white film with high opacity. The paint with nanosized TiO2 showed lowest values of diffuse reflectance in visible and infrared regions. The paints formulated with calcined TiO2, pigment showing higher particle sizes, reflected more efficiently the infrared region (700 to 2500 nm). Thermal treatment of nanometric TiO2 resulted in a pigment with particle size suitable for application of heat reflective paints.

Orientador: Inés Joekes / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T11:57:45Z (GMT). No. of bitstreams: 1 Alves_ScheilaDaianaFausto_M.pdf: 2196472 bytes, checksum: c6f04b6d2db3f6b1a2f50a2fabb1e67f (MD5) Previous issue date: 2013 / Resumo: Os cabelos tingidos, como é de conhecimento comum, desbotam com o passar do tempo. Estudos mostram que tanto cabelos naturais quanto tingidos apresentam desbotamento quando expostos à radiação ultravioleta, e este mesmo fenômeno também é observado em outras fibras naturais. Além disso, o processo de lavagem tem grande influência nesta perda de cor. No entanto, há poucos estudos que combinem os efeitos da radiação ao de tensoativos, utilizados no processo de lavagem. Neste trabalho, estudamos a permanência da cor em cabelos Caucasianos tingidos frente à exposição à radiação UV-Vis e a três diferentes tensoativos, coco glucosídeo, cocoil sarcosinato de sódio e coco sulfato de sódio, de mesma cadeia apolar e diferente grupo polar. Cabelos castanhos foram oxidados antes do tingimento. Cabelos loiros foram tingidos sem oxidação prévia. Cabelos castanhos e loiros sem tingir foram usados como controles. Foram simulados danos diários por meio de irradiação em lâmpada de vapor de mercúrio e lavagens, em 30 ciclos sequenciais de 8 h de irradiação e uma lavagem. As diferenças de cor foram medidas por espectrofotometria de reflectância difusa.. Foram obtidos espectros no UV-Vis das soluções de lavagem com os diferentes tensoativos. Como esperado, todas as mechas, naturais e tingidas, apresentaram diferença de cor. No caso das mechas sem tingir, os espectros das soluções de lavagem correspondem aos das melaninas. No caso das mechas tingidas, as soluções de lavagem têm o mesmo perfil de absorbância que as soluções de tintura. As mechas oxidadas e tingidas desbotaram mais que as que foram apenas tingidas. Observou-se diferença entre o efeito dos tensoativos apenas nas mechas que foram tingidas. Tanto para o cabelo castanho oxidado e tingido quanto para o cabelo loiro tingido, a ordem de extração do pigmento é: coco sulfato de sódio > cocoil sarcosinato de sódio > coco glucosídeo, concordando com o respectivo índice HLB / Abstract: It is well known that dyed hair fades with time. There are studies showing that dyed and natural hair, besides other natural fibers, have their color lightened when exposed to ultraviolet radiation. Futhermore, shamppoing has a big effect on this color lightening. However, there are few studies combining the effects of radiation and surfactants. In this work, we studied the color durability in dyed Caucasian hair when exposed to radiation and three surfactants, coco glucoside, sodium cocoyl sarcosinate and sodium coco sulfate, with same carbonic chain and different polar groups. Brown hair was chemically bleached before dyeing and blond hair was dyed without previous oxidation. Brown and blond hair with no dyeing was used as control. Simulation of diary damages was done by a mercury vapor lamp and washing cycles, in 30 sequential cycles of 8 h of irradiation and one shampooing. Color changes were measured by diffuse reflectance spectroscopy (DRS), using CIELab system. UV-Vis spectra were obtained from washing solutions with the different surfactants. All tresses, natural and dyed, showed color changes. UV-Vis spectra of the washing solutions of the hair without dyeing are consistent with melanin spectra. Dyed hair washing solutions spectra have the same profile of the dye solutions. The chemically bleached and dyed tresses faded more than the only dyed ones. Differences among the surfactants were observed only in the dyed tresses The pigment removal order for both, oxidized and dyed and only dyed tresses is: sodium coco sulfate > sodium cocoyl sarcosinate > coco glucoside, agreeing with their HLB index / Mestrado / Físico-Química / Mestra em Química

For children with intractable seizures, surgical removal of epileptic foci, if identifiable and feasible, can be an effective way to reduce or eliminate seizures. The success of this type of surgery strongly hinges upon the ability to identify and demarcate those epileptic foci. The ultimate goal of this research project is to develop an effective technology for detection of unique in vivo pathophysiological characteristics of epileptic cortex and, subsequently, to use this technology to guide epilepsy surgery intraoperatively. In this PhD dissertation the feasibility of using optical spectroscopy to identify unique in vivo pathophysiological characteristics of epileptic cortex was evaluated and proven using the data collected from children undergoing epilepsy surgery. In this first in vivo human study, static diffuse reflectance and fluorescence spectra were measured from the epileptic cortex, defined by intraoperative ECoG, and its surrounding tissue from pediatric patients undergoing epilepsy surgery. When feasible, biopsy samples were taken from the investigated sites for the subsequent histological analysis. Using the histological data as the gold standard, spectral data was analyzed with statistical tools. The results of the analysis show that static diffuse reflectance spectroscopy and its combination with static fluorescence spectroscopy can be used to effectively differentiate between epileptic cortex with histopathological abnormalities and normal cortex in vivo with a high degree of accuracy. To maximize the efficiency of optical spectroscopy in detecting and localizing epileptic cortex intraoperatively, the static system was upgraded to investigate histopathological abnormalities deep within the epileptic cortex, as well as to detect unique temporal pathophysiological characteristics of epileptic cortex. Detection of deep abnormalities within the epileptic cortex prompted a redesign of the fiberoptic probe. A mechanical probe holder was also designed and constructed to maintain the probe contact pressure and contact point during the time dependent measurements. The dynamic diffuse reflectance spectroscopy system was used to characterize in vivo pediatric epileptic cortex. The results of the study show that some unique wavelength dependent temporal characteristics (e.g., multiple horizontal bands in the correlation coefficient map g(λref = 800 nm, λcomp,t)) can be found in the time dependent recordings of diffuse reflectance spectra from epileptic cortex defined by ECoG.

In recent decades, the rapid development of optical spectroscopy for tissue diagnosis has been indicative of its high clinical value. The goal of this research is to prove the feasibility of using diffuse reflectance spectroscopy and fluorescence spectroscopy to assess myocardial infarction (MI) in vivo. The proposed optical technique was designed to be an intra-operative guidance tool that can provide useful information about the condition of an infarct for surgeons and researchers. In order to gain insight into the pathophysiological characteristics of an infarct, two novel spectral analysis algorithms were developed to interpret diffuse reflectance spectra. The algorithms were developed based on the unique absorption properties of hemoglobin for the purpose of retrieving regional hemoglobin oxygenation saturation and concentration data in tissue from diffuse reflectance spectra. The algorithms were evaluated and validated using simulated data and actual experimental data. Finally, the hypothesis of the study was validated using a rabbit model of MI. The mechanism by which the MI was induced was the ligation of a major coronary artery of the left ventricle. Three to four weeks after the MI was induced, the extent of myocardial tissue injury and the evolution of the wound healing process were investigated using the proposed spectroscopic methodology as well as histology. The correlations between spectral alterations and histopathological features of the MI were analyzed statistically. The results of this PhD study demonstrate the applicability of the proposed optical methodology for assessing myocardial tissue damage induced by MI in vivo. The results of the spectral analysis suggest that connective tissue proliferation induced by MI significantly alter the characteristics of diffuse reflectance and fluorescence spectra. The magnitudes of the alterations could be quantitatively related to the severity and extensiveness of connective tissue proliferation.