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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
401

Ferramentas quimiom?tricas aplicadas a classifica??o de amostras de leite em p? e quantifica??o de prote?nas / Ferramentas quimiom?tricas aplicadas a classifica??o de amostras de leite em p? e quantifica??o de prote?nas

In?cio, Maria Raquel Cavalcanti 24 February 2010 (has links)
Made available in DSpace on 2014-12-17T15:41:52Z (GMT). No. of bitstreams: 1 MariaRCI_DISSERT.pdf: 3251511 bytes, checksum: ea24e2034f12435ffe63fbcaee9ff544 (MD5) Previous issue date: 2010-02-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work we used chemometric tools to classify and quantify the protein content in samples of milk powder. We applied the NIR diffuse reflectance spectroscopy combined with multivariate techniques. First, we carried out an exploratory method of samples by principal component analysis (PCA), then the classification of independent modeling of class analogy (SIMCA). Thus it became possible to classify the samples that were grouped by similarities in their composition. Finally, the techniques of partial least squares regression (PLS) and principal components regression (PCR) allowed the quantification of protein content in samples of milk powder, compared with the Kjeldahl reference method. A total of 53 samples of milk powder sold in the metropolitan areas of Natal, Salvador and Rio de Janeiro were acquired for analysis, in which after pre-treatment data, there were four models, which were employed for classification and quantification of samples. The methods employed after being assessed and validated showed good performance, good accuracy and reliability of the results, showing that the NIR technique can be a non invasive technique, since it produces no waste and saves time in analyzing the samples / Neste trabalho foram utilizadas ferramentas quimiom?tricas para classificar e quantificar o teor de prote?nas em amostras de leite em p?. Empregou-se a espectroscopia NIR com reflect?ncia difusa associada a t?cnicas multivariadas. Primeiramente, realizou-se um m?todo explorat?rio das amostras atrav?s da an?lise das componentes principais (PCA),em seguida a classifica??o de modelagem independente para analogia de classes (SIMCA). Dessa forma se tornou poss?vel classificar as amostras que se agruparam por semelhan?as em sua composi??o. Por fim, as t?cnicas de regress?o por m?nimos quadrados parciais (PLS) e regress?o por componentes principais (PCR) permitiram a quantifica??o do teor de prote?nas nas amostras de leite em p?, comparadas com o m?todo de refer?ncia Kjeldahl. Um total de 53 amostras de leite em p? comercializadas nas regi?es metropolitanas de Natal, Salvador e Rio de Janeiro foram adquiridas para an?lise, em que ap?s pr?-tratamento dos dados obtidos, foram encontrados quatro modelos, os quais empregaram-se para a classifica??o e quantifica??o das amostras. Os m?todos empregados ap?s serem avaliados e validados apresentaram bom desempenho, demonstrando exatid?o e confiabilidade nos resultados obtidos, mostrando que a t?cnica NIR pode ser uma t?cnica n?o invasiva, uma vez que n?o produz res?duos e ainda economiza tempo na an?lise das amostras
402

Constru??o de modelos multivariados para determina??o de lip?dios totais e unidade em leite em p? comercial utilizando espectroscopia no infravermelho pr?ximo

Cabral, Alessandra Miranda 15 August 2011 (has links)
Made available in DSpace on 2014-12-17T15:41:56Z (GMT). No. of bitstreams: 1 AlessandraMC_DISSERT.pdf: 3533058 bytes, checksum: de92ff683335d9aa6c119013acb5b5d0 (MD5) Previous issue date: 2011-08-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work calibration models were constructed to determine the content of total lipids and moisture in powdered milk samples. For this, used the near-infrared spectroscopy by diffuse reflectance, combined with multivariate calibration. Initially, the spectral data were submitted to correction of multiplicative light scattering (MSC) and Savitzsky-Golay smoothing. Then, the samples were divided into subgroups by application of hierarchical clustering analysis of the classes (HCA) and Ward Linkage criterion. Thus, it became possible to build regression models by partial least squares (PLS) that allowed the calibration and prediction of the content total lipid and moisture, based on the values obtained by the reference methods of Soxhlet and 105 ? C, respectively . Therefore, conclude that the NIR had a good performance for the quantification of samples of powdered milk, mainly by minimizing the analysis time, not destruction of the samples and not waste. Prediction models for determination of total lipids correlated (R) of 0.9955, RMSEP of 0.8952, therefore the average error between the Soxhlet and NIR was ? 0.70%, while the model prediction to content moisture correlated (R) of 0.9184, RMSEP, 0.3778 and error of ? 0.76% / Neste trabalho foram constru?dos modelos de calibra??o para determinar os teores de lip?dios totais e umidade em amostras de leite em p?. Para isso, utilizou-se a espectroscopia no infravermelho pr?ximo por reflect?ncia difusa, aliado ? calibra??o multivariada. Inicialmente, os dados espectrais foram submetidos ? corre??o multiplicativa do espalhamento da luz (MSC) e alisamento de Savitzsky-Golay. Em seguida, as amostras foram divididas em subgrupos por aplica??o da an?lise por agrupamento hier?rquico das classes (HCA) e crit?rio de Ward Linkage. Desta forma, tornou-se poss?vel construir modelos de regress?o por m?nimos quadrados parciais (PLS) que permitiu a calibra??o e previs?o dos teores de lip?dios e umidade, com base nos valores obtidos por m?todos de refer?ncia de Soxhlet e secagem a 105 ? C, respectivamente. Portanto, conclui-se que o NIR apresentou um bom desempenho para quantifica??o de amostras de leite em p?, principalmente pela minimiza??o do tempo das an?lises, n?o destrui??o das amostras e n?o gera??o de res?duos. Os modelos de previs?o para determina??o de lip?dios totais apresentaram correla??o (R) de 0,9955, RMSEP de 0,8952, por conseguinte, o erro m?dio entre o Soxhlet e o NIR foi ? 0,70%, enquanto o modelo de previs?o para teor de umidade apresentou correla??o (R) de 0,9184, RMSEP, 0,3778 e erro de ? 0,76%
403

Espectroscopia no infravermelho pr?ximo e m?todos de calibra??o multivariada aplicados ? determina??o simult?nea de par?metros bioqu?micos em plasma sangu?neo

Neves, Ana Carolina de Oliveira 04 February 2013 (has links)
Made available in DSpace on 2014-12-17T15:42:05Z (GMT). No. of bitstreams: 1 AnaCON_DISSERT.pdf: 2560306 bytes, checksum: 01b4c26da4748508add3442c02e1b43b (MD5) Previous issue date: 2013-02-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work, the quantitative analysis of glucose, triglycerides and cholesterol (total and HDL) in both rat and human blood plasma was performed without any kind of pretreatment of samples, by using near infrared spectroscopy (NIR) combined with multivariate methods. For this purpose, different techniques and algorithms used to pre-process data, to select variables and to build multivariate regression models were compared between each other, such as partial least squares regression (PLS), non linear regression by artificial neural networks, interval partial least squares regression (iPLS), genetic algorithm (GA), successive projections algorithm (SPA), amongst others. Related to the determinations of rat blood plasma samples, the variables selection algorithms showed satisfactory results both for the correlation coefficients (R?) and for the values of root mean square error of prediction (RMSEP) for the three analytes, especially for triglycerides and cholesterol-HDL. The RMSEP values for glucose, triglycerides and cholesterol-HDL obtained through the best PLS model were 6.08, 16.07 e 2.03 mg dL-1, respectively. In the other case, for the determinations in human blood plasma, the predictions obtained by the PLS models provided unsatisfactory results with non linear tendency and presence of bias. Then, the ANN regression was applied as an alternative to PLS, considering its ability of modeling data from non linear systems. The root mean square error of monitoring (RMSEM) for glucose, triglycerides and total cholesterol, for the best ANN models, were 13.20, 10.31 e 12.35 mg dL-1, respectively. Statistical tests (F and t) suggest that NIR spectroscopy combined with multivariate regression methods (PLS and ANN) are capable to quantify the analytes (glucose, triglycerides and cholesterol) even when they are present in highly complex biological fluids, such as blood plasma / No presente trabalho, a an?lise quantitativa de glicose, triglicer?deos e colesterol (total e HDL) em plasma sangu?neo de ratos e humanos foi realizada sem necessidade de pr?tratamentos de amostras, atrav?s do uso da espectroscopia no infravermelho pr?ximo (NIR), aliada a m?todos multivariados. Para tanto, foram comparadas diferentes t?cnicas e algoritmos utilizados para pr?-processamentos de dados, sele??o de vari?veis e regress?es multivariadas, tais como a regress?o por m?nimos quadrados parciais (PLSR), regress?o n?o linear via redes neurais artificiais (ANN), regress?o por m?nimos quadrados parciais por intervalos (iPLS), algoritmo gen?tico (GA), algoritmo das proje??es sucessivas (SPA), entre outros. Para as determina??es em sangue de ratos, os algoritmos de sele??o de vari?veis apresentaram resultados satisfat?rios tanto em rela??o aos coeficientes de correla??o (R?) quanto para os valores de erro quadr?tico m?dio de previs?o (RMSEP) para os tr?s analitos, especialmente para triglicer?deos e colesterol-HDL. Os valores de RMSEP para glicose, triglicer?deos e colesterol-HDL atrav?s do melhor modelo PLS foram de 6,08, 16,07 e 2,03 mg dL-1, respectivamente. Para as determina??es em sangue de humanos, as previs?es atrav?s de modelos PLS apresentaram resultados insatisfat?rios, com comportamento n?o linear e presen?a de bias. A regress?o ANN foi investigada como uma alternativa ao PLS, por sua habilidade de modelar sistemas n?o lineares. O erro quadr?tico m?dio de monitoramento (RMSEM) para glicose, triglicer?deos e colesterol total, para os melhores modelos ANN, foram de 13,20, 10,31 e 12,35 mg dL-1, respectivamente. Testes estat?sticos (F e t) sugerem que a espectroscopia NIR aliada a m?todos de regress?o multivariados (PLS e ANN) possuem capacidade de quantificar os analitos (glicose, triglicer?deos e colesterol) mesmo quando os mesmos est?o presentes em fluidos biol?gicos altamente complexos, como o plasma sangu?neo
404

Avaliação do processo de fabricação de comprimidos de Captopril (25 mg): aplicação da tecnologia analítica de processo e de ferramentas da qualidade e estatística / Manufacturing process evaluation of Captopril (25 mg) tablets: application of process analytical technology and quality tools and statistical

Cátia Panizzon Dal Curtivo 09 November 2011 (has links)
As Boas Práticas de Fabricação de Medicamentos (BPFM) enfatizam que a indústria farmacêutica deve dirigir seus esforços no sentido de compreender a variação do processo, incluindo as fontes, o grau de variação e o impacto dessa variação nas características de qualidade do produto. O processo de fabricação de medicamentos tem apresentado significativas mudanças, em especial no que se refere à introdução de tecnologias analíticas que permitem o controle do processo em tempo real. A abordagem baseada na análise de risco e no novo Sistema de Qualidade Farmacêutica constitui ponto central das BPFM para o século XXI. Os órgãos regulatórios têm exigido da indústria farmacêutica sua adesão na melhoria contínua relativa ao desempenho de seus processos e, por consequência, na qualidade do produto. O objetivo do presente trabalho foi o desenvolvimento e validação de método analítico empregando espectroscopia no infravermelho próximo, assim como a avaliação do processo de fabricação de comprimidos de Captopril 25 mg, empregando abordagem racional-científica. Com referência à avaliação do processo, foram adotadas as seguintes ferramentas: análise de modos e efeitos de falhas (FMEA); gráficos de controle; índices de capacidade e análise de variância (ANOVA). A espectroscopia por infravermelho próximo (NIR) foi selecionada por apresentar maior rapidez na obtenção dos resultados, maior simplicidade na preparação das amostras, multiplicidade das análises a partir de uma única leitura e por apresentar característica não invasiva. Os resultados comprovaram a adequação dessa tecnologia na avaliação quantitativa do Captopril nas etapas de mistura de pós e de compressão. Os desvios padrão relativos na determinação da uniformidade de Captopril na mistura de pós e nos comprimidos empregando método no NIR foram, respectivamente 3,15 e 0,18%. No que se refere à avaliação da estabilidade e da capacidade do processo, as ferramentas adotadas permitiram a compreensão das fontes de variabilidade, assim como a determinação de seu grau, nas diferentes etapas do processo. Os índices de capacidade (CpK) relativos à uniformidade de Captopril (% p/v) na mistura de pós, ao peso médio do comprimido, à uniformidade de conteúdo e à % (p/v) dissolvida de Captopril, no ensaio de dissolução, foram 0,70, 1,94, 1,80 e 2,19, respectivamente. / The Good Manufacturing Practices (GMP) for Medicinal Products point out that the pharmaceutical industry must direct efforts to understand the variation of the processes, including the sources, the level of variation and the variation impact on the process in characteristics of the product. The manufacturing process has shown meaningful changes, especially in the introduction of new analytical technologies that allow the process control in real time. The approach based on risk analyses and on the new Pharmaceutical Quality System is a central key for the GMP for the XXI century. The Regulatory Agencies have demanded the pharmaceutical industry to adhere the continuous improvement related to the performance of its processes and, consequently, the product quality. Thus, the present paper aimed the development and validation of the analytical method employing NIR spectroscopy as the assessment of manufacturing process of Captopril 25 mg tablets, using rational scientific approach. Regarding the process assessment, the following tools were adopted: analysis of failure modes and effects analysis (FMEA), control charts, capability indexes, as well as analysis of variance (ANOVA). The near-infrared spectroscopy was selected due to its greater speed in getting the results, simplicity in sample preparation, and multiplicity of analysis from a single reading and provide non-invasive feature. The results confirmed the suitability of this technology in quantitative assessment of Captopril on the steps of mixing powders and compression. The relative standard deviations for the determination of Captopril uniformity in the post mixtures and in the tablets employing NIR were 3,15 e 0,18%, respectively. In reference to the stability assessment and process capacity, the tools adopted permitted the understanding of the sources of variability, as well as the determination of their level in different phases of the process. The capacity indexes relating to Captopril uniformity (% p/v) in the powder mixture, the average weight of the tablet, the content uniformity and the % (p/v) dissolved Captopril, in the dissolution assay were 0,70, 1,94, 1,80 and 2,19, respectively.
405

Determinação simultânea de valsartana, hidroclorotiazida e besilato de anlodipino em formulação farmacêutica por infravermelho próximo e calibração multivariada

Becker, Natana 21 August 2015 (has links)
Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-21T20:29:32Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Natana Becker.pdf: 1266893 bytes, checksum: 018f6e1bf563008837c534403e5c801e (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-21T20:29:52Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Natana Becker.pdf: 1266893 bytes, checksum: 018f6e1bf563008837c534403e5c801e (MD5) / Made available in DSpace on 2016-09-21T20:29:52Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Natana Becker.pdf: 1266893 bytes, checksum: 018f6e1bf563008837c534403e5c801e (MD5) Previous issue date: 2015-08-21 / Os fármacos valsartana (VAL), hidroclorotiazida (HCT) e besilato de anlodipino (ANL) são utilizados em associação e comercializados no Brasil como agentes anti-hipertensivos. Geralmente a determinação simultânea destes fármacos é realizada por cromatografia líquida de alta eficiência (CLAE). Este trabalho teve por objetivo a determinação simultânea de VAL, HCT e ANL em uma formulação comercial de comprimidos através da técnica de espectroscopia no infravermelho próximo com transformada de Fourier e acessório de esfera de integração (FT-NIR) associadas a métodos de análise multivariada. Os modelos de calibração foram construídos utilizando mínimos quadrados parciais (PLS) e seleção de variáveis através dos algoritmos mínimos quadrados parciais por intervalo (iPLS) e mínimos quadrados parciais por sinergismo de intervalos (siPLS). Um total de 36 amostras sintéticas e 1 amostra real (26 amostras para o conjunto de calibração e 11 amostras para o conjunto de previsão), foram utilizadas as faixas de concentração de 261,9-500,0 mg g-1 para VAL; 20,2-83,3 mg g-1 para HCT e 11,6-49,6 mg g-1 para ANL. Os dados espectrais foram adquiridos na faixa de 4000 a 10000 cm-1 com resolução de 4 cm-1 por FT-NIR. Os melhores modelos foram obtidos através da utilização do pré-processamento centrado na média (CM) e do tratamento de correção do espalhamento de luz (MSC). O erro relativo de previsão (RSEP%) de 1,27% para VAL, 1,92% para HCT e 5,19%para ANL, foi obtido após seleção dos melhores intervalos por siPLS para dados obtidos por FT-NIR. Não foi encontrada diferença significativa (teste t-pareado, 95% de confiança) entre os valores do método de referência e do método proposto. Os resultados mostraram que modelos de regressão PLS (associados a métodos de seleção de variáveis, como iPLS e siPLS) combinados com FT-NIR são promissores no desenvolvimento de metodologias mais simples, rápidas e não destrutivas. Estes modelos permitem a determinação simultânea de VAL, HCT e ANL na formulação farmacêutica. / Valsartan (VAL), hydrochlorothiazide (HCT) and amlodipine besylate (ANL) drugs are used in combination and they are commercialized in Brazil as antihypertensive agents. Generally, the simultaneous determination of these drugs is carried out by high performance liquid chromatography (CLAE). This study aimed to the simultaneous determination of VAL, HCT, and ANL in a comercial tablet formulation through the technique near infrared spectroscopy with Fourier transform and integrating sphere accessory (FT- NIR) associated with methods of multivariate analysis. The calibration models were built using partial least squares (PLS) and variable selection through partial least squares algorithms for interval (iPLS) and partial least squares by synergism intervals (siPLS). A total of 36 synthetic samples 1 and commercial sample (26 samples for the calibration sample set and 11 for the prediction set), were used the concentration ranges of 261.9-500.0 mg g-1 for VAL; 20.2-83.3 mg g-1 for HCT and 11.6-49.6 mg g-1 for ANL. The spectral data were acquired in the range 4000-10000 cm-1 with resolution of 4 cm-1 by FT-NIR. Multiplicative scatter correction (MSC) and the data centered in the media (CM) produced the best models. A relative standard error of prediction (RSEP%) of 1.27% for VAL, 1.92% for HCT and 5.19% for ANL was obtained after selection of the best intervals for data obtained by siPLS FT-NIR. There was no significant difference (paired t-test, 95% confidence) between the values of the reference method and the proposed method. Results showed that PLS models regression (associated with iPLS and siPLS regression models) combined with FT-NIR are promising in the development of simpler methods, rapid and non-destructive. These models allow simultaneous determination of VAL, HCT, and ANL in the pharmaceutical formulation.
406

Biomarqueurs fluorescents, marqueurs et instruments optiques dédiés pour le diagnostic in vivo des pathologies cornéennes / Fluorescent biomarkers, markers and dedicated optical instruments for the in vivo diagnosis of corneal diseases

Courrier, Emilie 27 September 2017 (has links)
Un déséquilibre dans les mécanismes de défense de la cornée peut entraîner une invasion par des micro-organismes (MO) et générer une kératite infectieuse (KI), ou encore un syndrome sec. Les KI sont la première cause de cécité monoculaire. Le syndrome sec, également fréquent, est sujet à de nombreuses études cliniques pour l’évaluation de nouveaux traitements. L’objectif de cette thèse est de mettre au point des méthodes d’imagerie pour le diagnostic et le suivi des pathologies de la surface oculaire au travers de deux projets innovants : 1/ le projet FLUOCOR consistant à développer une solution complète de diagnostic rapide in vivo des MO les plus souvent responsables des KI afin de débuter immédiatement le traitement adapté et améliorer le pronostic visuel final. Cette solution comprendra des BioMarqueurs fluorescents (BMfs) spécifiques des agents infectieux, fluorescents dans le rouge ou le proche infrarouge non éblouissant et un nouvel instrument optique de détection. Des BMfs basés sur le couplage de BODIPY innovant avec des molécules ciblant les MO ont été obtenus. Des tests in vitro ont montré une bonne spécificité mais les tests ex vivo sur cornées humaines ont montré une fixation non spécifique sur les cellules épithéliales. Pour pallier ce manque de spécificité, le couplage de ces BODIPY sur des anticorps dirigés contre les MO est en cours. 2/ le projet FLUOSCOPE qui a permis de développer une nouvelle stratégie d’imagerie de la surface oculaire pour le suivi du syndrome sec, de la méthode d’instillation des colorants jusqu’au traitement d’images, en passant par la conception d’un instrument optique désormais industrialisé par les laboratoires Théa. / An imbalance in the defence system of cornea can result in several diseases, like infectious keratitis (IK) in case of invasion by microorganisms (MO) or dry eye in case of insufficient tear quality and/or quality. IK are the first cause of unilateral blindness worldwide. Sicca syndrome, also frequent, is the subject of numerous clinical trials assessing new treatments. The aim of the PhD Thesis work is to develop new imaging methods for the diagnosis and follow-up of diseases of the ocular surface. Two innovative project were conducted: 1/ the FLUOCOR project consists in developing a complete solution of rapid in vivo etiologic diagnosis of IK, for the most frequent and/or severe infections to allow rapid starting of the most adapted treatment in order to improve the final visual prognosis. This solution will comprise fluorescent biomarkers (excitable by sustainable non blinding red or near infrared lights) specific to the target MO, and a new optical imaging device for their detection. Biomarkers based on new BODIPY coupled with molecules targeting the MO were obtained with a good in vitro specificity. Nevertheless, on ex vivo human corneas they stained superficial epithelial cells. In order to overcome this difficulty, the coupling of BODIPY on specific antibodies targeting the MO is ongoing; 2/ the FLUOSCOPE project that allowed development of a new strategy of ocular surface imaging for the diagnosis and follow up of sicca syndrome. The complete chain was revisited from the instillation of the dye to the objective quantification of staining by image analysis, through the development of a prototype of imaging device, now industrialized by les Laboratoires Thea.
407

NONINVASIVE MULTIMODAL DIFFUSE OPTICAL IMAGING OF VULNERABLE TISSUE HEMODYNAMICS

Zhao, Mingjun 01 January 2019 (has links)
Measurement of tissue hemodynamics provides vital information for the assessment of tissue viability. This thesis reports three noninvasive near-infrared diffuse optical systems for spectroscopic measurements and tomographic imaging of tissue hemodynamics in vulnerable tissues with the goal of disease diagnosis and treatment monitoring. A hybrid near-infrared spectroscopy/diffuse correlation spectroscopy (NIRS/DCS) instrument with a contact fiber-optic probe was developed and utilized for simultaneous and continuous monitoring of blood flow (BF), blood oxygenation, and oxidative metabolism in exercising gastrocnemius. Results measured by the hybrid NIRS/DCS instrument in 37 subjects (mean age: 67 ± 6) indicated that vitamin D supplement plus aerobic training improved muscle metabolic function in older population. To reduce the interference and potential infection risk on vulnerable tissues caused by the contact measurement, a noncontact diffuse correlation spectroscopy/tomography (ncDCS/ncDCT) system was then developed. The ncDCS/ncDCT system employed optical lenses to project limited numbers of sources and detectors on the tissue surface. A motor-driven noncontact probe scanned over a region of interest to collect boundary data for three dimensional (3D) tomographic imaging of blood flow distribution. The ncDCS was tested for BF measurements in mastectomy skin flaps. Nineteen (19) patients underwent mastectomy and implant-based breast reconstruction were measured before and immediately after mastectomy. The BF index after mastectomy in each patient was normalized to its baseline value before surgery to get relative BF (rBF). Since rBF values in the patients with necrosis (n = 4) were significantly lower than those without necrosis (n = 15), rBF levels can be used to predict mastectomy skin flap necrosis. The ncDCT was tested for 3D imaging of BF distributions in chronic wounds of 5 patients. Spatial variations in BF contrasts over the wounded tissues were observed, indicating the capability of ncDCT in detecting tissue hemodynamic heterogeneities. To improve temporal/spatial resolution and avoid motion artifacts due to a long mechanical scanning of ncDCT, an electron-multiplying charge-coupled device based noncontact speckle contrast diffuse correlation tomography (scDCT) was developed. Validation of scDCT was done by imaging both high and low BF contrasts in tissue-like phantoms and human forearms. In a wound imaging study using scDCT, significant lower BF values were observed in the burned areas/volumes compared to surrounding normal tissues in two patients with burn. One limitation in this study was the potential influence of other unknown tissue optical properties such as tissue absorption coefficient (µa) on BF measurements. A new algorithm was then developed to extract both µa and BF using light intensities and speckle contrasts measured by scDCT at multiple source-detector distances. The new algorithm was validated using tissue-like liquid phantoms with varied values of µa and BF index. In-vivo validation and application of the innovative scDCT technique with the new algorithm is the subject of future work.
408

The multi-coloured universe of 2S 0114+650

Farrell, Sean Adam, Physical, Environmental & Mathematical Sciences, Australian Defence Force Academy, UNSW January 2007 (has links)
This thesis presents the results of a comprehensive multi-wavelength study of the high mass X-ray binary 2S 0114+650. This enigmatic source has previously been proposed to be the first in a new class of super-slow X-ray pulsars, containing a neutron star revolving once every 2.7 h. The 11.6 d orbital period of this system has been well established in both X-ray and optical wavelengths. During the initial stages of the research presented in this thesis we discovered an additional 30.7 d ???super-orbital??? modulation in the X-ray emission from this source. While similar periodicities seen in other X-ray binaries are commonly attributed to the precession of a warped accretion disc, the observational evidence suggests the absence of such a disc in 2S 0114+650. The purpose of this project is thus to determine the nature of the super-orbital modulation and to better constrain the astrophysical parameters of this system. To investigate the long-term variability we analysed ~8.5 yr of archived data from the Rossi X-ray Timing Explorer space telescope. The problem of the spurious ~24 h periods in this data was solved as a by-product of these studies. Follow-up pointed observations were obtained with this satellite in order to examine the spectral and temporal behaviour over the spin, orbital and super-orbital timescales. Independent confirmation of the super-orbital modulation was performed using ~2 yr of data from the INTEGRAL satellite obtained during a long-term monitoring campaign of the Cassiopeia region. The evolution of the spin, orbital and super-orbital periods over ~10 yr was examined using archived data from the Rossi X-ray Timing Explorer satellite. Radio observations were performed with the Giant Meterwave Radio Telescope to search for any radio emission associated with this source and to determine whether it is variable over the known periodicities. Near infrared observations were performed with the Mt Abu telescope to determine whether a Be star nature can be ruled out for the optical component. Finally, a statistical analysis of the properties of the confirmed super-orbital X-ray binaries was performed in order to search for commonalities between these systems.
409

Thoracic Aortic Surgery : Epidemiology, Outcomes, and Prevention of Cerebral Complications

Olsson, Christian January 2006 (has links)
<p>The mortality of thoracic aortic diseases (mainly aneurysms and dissections) is high, even with surgical treatment. Epidemiology and long-term outcomes are incompletely investigated. Stroke is a major complication contributing to mortality, morbidity, and possibly to reduced quality of life. </p><p><i>Study I</i> Increasing incidence of thoracic aortic diseases 1987 – 2002 was demonstrated (n=14229). Annual number of operations increased eight-fold. Overall long-time survival was 92%, 77%, and 57% at 1, 5, and 10 years. Risk of operative and long-term mortality was reduced across time.</p><p><i>Study II</i> 2634 patients operated on the proximal thoracic aorta (Swedish Heart Surgery register) were examined. Aortic valve replacement, coronary revascularization, emergency operation, and age were independently associated with surgical death. Long-term mortality was similar for aneurysms and dissections. Operative mortality was reduced (13.7% vs 7.2%) for aneurysms but remained unchanged (22.3% vs 22.4%) for dissections across time.</p><p><i>Study III</i> 65 patients underwent selective antegrade cerebral perfusion (SACP) uni- or bilaterally. Stroke was significantly more common after unilateral SACP (29% vs 8%, p=0.045), confirmed by propensity score-matched analysis. Subclavian artery cannulation with Seldinger-technique entailed vascular complication in one case (1.5%).</p><p><i>Study IV</i> Near-infrared spectroscopy (NIRS) was used to monitor cerebral tissue saturation (rSO2) during SACP in 46 patients. Lower rSO2 were encountered (1) in patients suffering a stroke (2) with unilateral SACP, and (3) in the affected hemisphere of stroke victims. A decrease of rSO2 by 14 – 21% from baseline increased the risk of stroke significantly.</p><p><i>Study V</i> Quality of life (QoL) in 76 survivors of thoracic aortic surgery was examined with the SF-36 health questionnaire. Except for pain, QoL was reduced in all dimensions. QoL was not affected by acuity of operation. Tendencies of lower QoL after descending aortic operations, after major complications, and with persistent dysfunction were non-significant.</p>
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Nanoparticles for Targeted Drug Delivery

Chow, Gan-Moog 01 1900 (has links)
Nanoparticles were synthesized and modified for target drug delivery. The research involved the aqueous synthesis of near infrared (NIR) sensitive Au-Au<sub>2</sub>S nanoparticles. An anti-cancer drug (<i>cis-platin</i>) was subsequently adsorbed onto the Au-Au<sub>2</sub>S nanoparticle surface via the 11-mercaptoundecanoic acid layers. The results showed that the degree of adsorption of cis-platin onto Au-Au<sub>2</sub>S nanoparticles was controlled by the pH value of solution, and the rate of drug release was sensitive to NIR irradiation. The results of the synthesis, drug-release properties and nanoparticle-cell interactions will be discussed. / Singapore-MIT Alliance (SMA)

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