Accurately assessing the extent of myocardial tissue injury induced by Myocardial infarction (MI) is critical to the planning and optimization of MI patient management. With this in mind, this study investigated the feasibility of using combined fluorescence and diffuse reflectance spectroscopy to characterize a myocardial infarct at the different stages of its development. An animal study was conducted using twenty male Sprague-Dawley rats with MI. In vivo fluorescence spectra at 337 nm excitation and diffuse reflectance between 400 nm and 900 nm were measured from the heart using a portable fiber-optic spectroscopic system. Spectral acquisition was performed on - (1) the normal heart region; (2) the region immediately surrounding the infarct; and (3) the infarcted region - one, two, three and four weeks into MI development. The spectral data were divided into six subgroups according to the histopathological features associated with various degrees / severities of myocardial tissue injury as well as various stages of myocardial tissue remodeling, post infarction. Various data processing and analysis techniques were employed to recognize the representative spectral features corresponding to various histopathological features associated with myocardial infarction. The identified spectral features were utilized in discriminant analysis to further evaluate their effectiveness in classifying tissue injuries induced by MI. In this study, it was observed that MI induced significant alterations (p < 0.05) in the diffuse reflectance spectra, especially between 450 nm and 600 nm, from myocardial tissue within the infarcted and surrounding regions. In addition, MI induced a significant elevation in fluorescence intensities at 400 and 460 nm from the myocardial tissue from the same regions. The extent of these spectral alterations was related to the duration of the infarction. Using the spectral features identified, an effective tissue injury classification algorithm was developed which produced a satisfactory overall classification result (87.8%). The findings of this research support the concept that optical spectroscopy represents a useful tool to non-invasively determine the in vivo pathophysiological features of a myocardial infarct and its surrounding tissue, thereby providing valuable real-time feedback to surgeons during various surgical interventions for MI.

No description available.

Orientador: Carlos Roberto de Souza Filho / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-26T19:58:27Z (GMT). No. of bitstreams: 1 CorreaPabon_RosaElvira_D.pdf: 10125024 bytes, checksum: 73b222e9787711d668d1cc3b8a2845ba (MD5) Previous issue date: 2015 / Resumo: Essa pesquisa compreende a aplicação de técnicas de espectroscopia de refletância e imageamento hiperespectral aeroportado visando o aprimoramento de métodos e sistemas de monitoramento de solos expostos à vazamentos de hidrocarbonetos (HCs), em instalações petrolíferas. O trabalho compreendeu um experimento em ambiente de laboratório, onde contaminações controladas foram realizadas buscando-se simular, em escala reduzida, solos impactados por vazamentos de HCs. Os principais objetivos do experimento foram os seguintes: (i) caracterizar as assinaturas espectrais dos solos impregnados com HCs, em diferentes proporções, no intervalo do espectro visível e infravermelho (350 ¿ 2500 nm); (ii) descrever as principais feições de absorção espectral diagnósticas da presença do HC; (iii) estabelecer os limites de detecção do HC na mistura; (iv) gerar modelos matemáticos de simples aplicação, que permitam estimar o tipo e volume de HCs envolvido na contaminação. Considerando a base gerada nas investigações experimentais, em um segundo passo, técnicas digitais de extração de informações espectrais foram aplicadas a um conjunto de imagens hiperespectrais adquiridas sobre instalações petrolíferas e áreas experimentais de vazamentos de HCs líquidos em escala real. Como resultado, foi possível identificar a distribuição espacial de solos e outros alvos potencialmente contaminados nessas áreas, cujos principais focos foram comprovados no campo. O estudo sugere o grande potencial de aplicação destas tecnologias ultraespectrais e hiperespectrais no monitoramento de solos em torno das linhas de transporte de petróleo e de refinarias, o que pode contribuir para aquilatar a segurança e desempenho operacional de dutos de transporte e armazenamento de HCs na indústria do petróleo / Abstract: This research involves the application of reflectance and imaging spectroscopy techniques to improve methods and systems to monitor bare soils contaminated by hydrocarbon (HC) leaks in petroleum refinaries and pipelines. The study involves an experiment, conducted under laboratory conditions; where controlled contaminations were made aiming to simulate, in a small scale, soils contaminated with hydrocarbon leaks. The main objectives of the experiment are the following: (i) to characterize the spectral signature of contaminated soils, with several proportions of HCs, within visible and infrared wavelengths (350 ¿ 2500 nm); (ii) to describe the main, diagnostic absorption bands linked to the presence of HCs, (iii) to establish concentration limits for the detection of HCs in substrate mixtures; (iv) to generate simple models to estimate the HC type and impregnation level involved in the contamination. The comprehensive spectral libraries yielded during the laboratory experiments were used, in a second step, as an input for the application of digital information extraction techniques to hyperspectral image datasets acquired on real petroleum facilities and field experimental areas of liquid HC leaks. Given such representative scenarios, it was possible to identify the spatial distribution of soils and other potentially contaminated targets in these areas, which were verified further in the field and corresponded to sites with leaks. The study suggests the great potential for intelligent use of ultraspectral and hyperspectral technologies for monitoring soils around pipelines and refineries, adding to the safety and operational performance of oil pipelines and storage in the petroleum industry / Doutorado / Geologia e Recursos Naturais / Doutora em Ciências

Routine non-destructive analyses of rocks and minerals in slab or powder form maybe practicable by the application of the technique of attenuated total reflection [ATR] in infrared [IR] spectrophotometry. An atlas of spectra would serve the analytical chemist and geologist, who in turn would serve the miner, the lapidarist, and other groups interested in rocks and minerals. No effort has been made to produce an atlas of spectra of rocks and minerals by ATR. No ATR spectra of rocks and minerals were found in the literature. The history of ATR indicates that it is still in its early stages of development. The application of all phases of IR to the study of minerals has been employed much less than to the study of organics. For the analysis of rocks and minerals, ATR is more versatile and more convenient than most methods. It is applicable for both opaque and transparent materials of thick or thin films. It is often requires no sample preparation. This study of ATR of minerals involves the development of an atlas of mineral powder spectra and of mineral slab spectra, the comparison of the two sets of spectra with each other, and the comparison of powder spectra from ATR with transmission spectra in the literature. the study is confined to the spectral range of 0.5 - 15.5 microns.

Optical spectroscopy is a real-time technique that holds promise as a potential surgical guidance tool. Fiber-optic diffuse reflectance spectroscopy (DRS) is a technique capable of intraoperative tissue differentiation. The common DRS focuses on estimating chromophore concentrations in the visible (VIS) wavelength range (400-1000 nm), where spectroscopic features of the blood, pigments, and tissue densities are present between 400 and 700 nm. Recently, extended-wavelength DRS (EWDRS), which extends the spectral window from the VIS through the short wave-infrared region (SWIR) up to 1800 nm, has emerged as a promising approach for identifying nerves and nerve bundles due to the SWIR including robust tissue absorption features associated with nerve-tissue related chromophores, including lipids, water and collagen proteins. One potential application of EWDRS is guiding minimally invasive surgical techniques, such as laparoscopy, where inadvertent injury to pelvic autonomic nerves (PANs) is a primary complication that can result in over 70% of patients suffering long-term side effects, including urinary incontinence and sexual dysfunction. There is a need for objective laparoscopic surgical guidance to precisely identify PANs from other tissues, and an improved basis for EWDRS development could assist clinical translation. Prior development of Fiber-optic DRS for tissue classification in the VIS greatly benefited from the application of modeling techniques for simulation of optical measurements, analysis, and fiber-probe design. Model-based analysis can inform fundamental understanding of measured signals in different measurement scenarios, such as the varying tissue morphologies possible in laparoscopic procedures, and guide application-specific fiber-probe design through comparison of unique illumination/collection geometries; however, the demonstration of these approaches in EWDRS is not widely reported. This dissertation focuses on the advancement of platforms for model-driven analysis of EWDRS for nerve identification. In order to advance the current state of EWDRS, a model-based characterization platform for analysis of a custom-developed fiber-optic EWDRS system was developed in Aim 1, which demonstrated agreement between data collected from optical phantoms, ex vivo microsurgical model, and Monte Carlo (MC) computational simulations of EWDRS measurements. In Aim 2, the model-based platform was used to perform a detailed analysis of two similar EWDRS fiber-optic probes, which indicated subtle differences in the depth-dependent measurement performance. Finally, in Aim 3, the custom EWDRS was prepared for adapting laparoscopic use to demonstrate laparoscopic measurement feasibility, including evaluation of placement variance and customized EWDRS package for short-distance transportation. The successful completion of this dissertation will enable improved analyses of EWDRS devices for a variety of future intraoperative applications. / Bioengineering

No description available.

Imaging instruments are required for accurate tumor resection during neurosurgery, especially in the case of glioblastoma multiforme (GBM) - the most common and aggressive malignant glioma. However, current intraoperative imaging techniques for detection of glioma either suffer low sensitivity and low specificity or require a significant capital cost. Advances in diffuse reflectance spectroscopy and fluorescence spectroscopy have offered high sensitivity and high specificity in differentiating tumors from normal tissues with much lower capital cost. Whereas diffuse reflectance spectroscopy alone and fluorescence spectroscopy alone has been used in limited studies to differentiate normal brain tissues from brain tumors with moderate sensitivity and specificity, low specificity and sensitivity were usually observed when studying high grade glioma (HGG) such as GBM. Furthermore, optical properties and diffuse reflectance signal of HGG and low grade glioma (LGG) have not been observed separately, and thus a relation between optical properties and glioma progression has not been established. Intraoperative differentiation of GBM and LGG can be helpful in making treatment plan at the first surgery. This thesis focuses on characterizing a previous integrated system of diffuse reflectance spectroscopy and fluorescence spectroscopy to extract optical properties and fluorescence properties of LGG and GBM. First, tissue-simulating phantom models were developed to calibrate the integrated system. The direct method and Mie theory were used to calculate optical scattering of the phantoms while Beer-Lambert’s law was used to calculate optical absorption. Second, an experimental method was introduced to recover intrinsic fluorescence because the measured fluorescence signal is likely distorted by the presence of scatterers and absorbers in tissue (i.e. hemoglobin). Third, an experimental method was developed to recover optical properties of both GBM and LGG. In addition, the sensitivity and specificity of the integrated system was optimized. / Thesis / Doctor of Philosophy (PhD)

No description available.

Sustainability of the soybean industry relies on the growth of new industries and the continued improvement of seeds for utilization. Grower adoption and growth of the edamame industry has been slow in part due to insufficient information on its potential profitability and marketability. As such, the first and second objectives of this thesis aimed at 1) determining production costs of hand-harvested fresh edamame enterprise and 2) exploring consumer willingness-to-pay (WTP) for fresh, local, organic, and "on-the-stalk" marketed edamame. Sucrose, raffinose, and stachyose sugars hold tremendous implications for utilization of soybean seeds in livestock, soyfood, and probiotics industries. Current sugar phenotyping methods using high-performance liquid chromatography (HPLC) are costly and inefficient. Therefore, the third objective of this study was to develop calibrations to predict sugar content using near-infrared reflectance spectroscopy (NIRS). Results showed that labor accounted for 72% of production costs for edamame pods, which largely limits its profit potential. Mean WTP for fresh and local edamame exceeded their frozen and non-local counterparts by 94 and 88 cents, respectively. In addition, mean WTP for organic edamame exceeded non-GMO edamame by 33 cents. Pro-environmental attitudes appeared to be a consistent driver of WTP these three attributes. Meanwhile, a 40-cent discount for "on-the-stalk" edamame compared to pods indicates convenience may also be a factor in edamame marketability. Calibration development for sucrose and stachyose was successful, with R2cal, R2cv, RMSEC, and RMSECV of 0.901, 0.869, 0.516, and 0.596, and 0.911, 0.891, 0.361, and 0.405, respectively. Alternative methods should be investigated for quantification of raffinose. / Master of Science / Sustainability of the soybean industry relies on the growth of new industries and the continued improvement of seeds for utilization. Grower adoption and growth of the edamame industry has been slow in part due to insufficient information on its potential profitability and marketability. As such, the first and second objectives of this thesis aimed at 1) determining production costs of hand-harvested fresh edamame and 2) exploring relative marketing potential of fresh, local, organic, and "on-the-stalk" edamame. Sucrose, raffinose, and stachyose sugars hold tremendous implications for utilization of soybean seeds in livestock, soyfood, and probiotics industries. Current methods of quantifying sugar are costly and time inefficient. Therefore, the third objective of this study was to develop prediction models to estimate sugar content using near-infrared reflectance spectroscopy (NIRS). Results showed that labor accounted for 72% of production costs for edamame pods, which largely limits its profit potential. Fresh and local edamame showed considerable marketing potential over frozen and non-local edamame. In addition, organic edamame showed marginal marketing benefit over non-GMO. Pro-environmental attitudes were an important driver of these results. Meanwhile, on-the-stalk edamame shows poor marketing potential, likely due to preference for convenience of food preparation in the U.S. NIRS prediction models for sucrose and stachyose showed strong predictive accuracy and low error, suggesting potential for implementation. The prediction model for raffinose, however, remained poor.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Science. / Microfiche copy available in Archives and Science. / Bibliography: leaves 111-114. / Ph.D.