Decompression sickness (DCS) results from a sudden decrease in ambient pressure leading to super-saturation of tissues with inert gas and subsequent bubble formation within both tissues and blood. Perfluorocarbons (PFC) are able to dissolve vast amounts of non-polar gases. The administration of intravenous (I.V.) PFC emulsions reduce both morbidity and mortality of DCS, but the mechanism of this protective effect has not yet been demonstrated. Juvenile Dorper cross sheep between 16 and 24 kg (n=31) were anaesthetized and instrumented for physiological monitoring, the administration of I.V. fluids and sampling of arterial and mixed venous blood. Animals were placed in a hyperbaric chamber and compressed to 6.0 atmospheres absolute for 30 minutes, then rapidly decompressed. Upon chamber exit animals were randomly assigned to receive 6cc/kg of either PFC or saline control over 5 minutes beginning immediately after chamber exit. They were also randomized to receive one of 4 breathing gases post-chamber: 100% O2, 80/20 N2/O2, 50/50 HeO2, or 80/20 HeO2. Blood samples were drawn at 5, 10, 15, 30, 60, and 90 minutes to examine whole-body oxygenation. Respiratory gases were monitored and recorded in real-time using mass spectroscopy to examine nitrogen washout. PFC administration increased arterial oxygen content (16.30±0.27 vs. 14.75±0.25 mL/dL, p<0.0001), oxygen delivery (14.83±0.28 vs. 13.44±0.25 mL/minute/kg, p=0.0004), and tissue oxygen consumption (3.37±0.14 vs. 2.76±0.13 mL/minute/kg, p=0.0018) over saline control, but did not increase mixed venous oxygen content (12.45±0.26 vs. 11.74±0.24 mL/dL, p=0.0558) or extraction ratio (0.23±0.012 vs. 0.21±0.011, p=0.1869). PFC administration lowered the plateau of the curve, increasing the amount of nitrogen washout vs. saline control (22.22±1.566 vs. 15.98±1.380 mmHg, p= 0.0074). Breathing 80/20 HeO2 increased the decay constant of the curve, increasing the rate of washout vs. breathing 100% O2 (0.03176±0.001044 vs. 0.03096±0.0009402, p=0.5777). PFC improves whole-body oxygenation after severe DCS and increases the amount of nitrogen washout. Although the effects of both PFC and 80/20 HeO2 breathing were statistically significant the magnitude of the nitrogen washout effect is quite small, and unlikely to be clinically significant. Thus it is likely that the improved oxygenation is responsible for the previously-observed therapeutic effects of PFC in treating DCS.

<p>The work presented in this dissertation is focused on applying engineering methods to develop and explore probabilistic survival models for the prediction of decompression sickness in US NAVY divers. Mathematical modeling, computational model development, and numerical optimization techniques were employed to formulate and evaluate the predictive quality of models fitted to empirical data. In Chapters 1 and 2 we present general background information relevant to the development of probabilistic models applied to predicting the incidence of decompression sickness. The remainder of the dissertation introduces techniques developed in an effort to improve the predictive quality of probabilistic decompression models and to reduce the difficulty of model parameter optimization.</p><p>The first project explored seventeen variations of the hazard function using a well-perfused parallel compartment model. Models were parametrically optimized using the maximum likelihood technique. Model performance was evaluated using both classical statistical methods and model selection techniques based on information theory. Optimized model parameters were overall similar to those of previously published Results indicated that a novel hazard function definition that included both ambient pressure scaling and individually fitted compartment exponent scaling terms. </p><p>We developed ten pharmacokinetic compartmental models that included explicit delay mechanics to determine if predictive quality could be improved through the inclusion of material transfer lags. A fitted discrete delay parameter augmented the inflow to the compartment systems from the environment. Based on the observation that symptoms are often reported after risk accumulation begins for many of our models, we hypothesized that the inclusion of delays might improve correlation between the model predictions and observed data. Model selection techniques identified two models as having the best overall performance, but comparison to the best performing model without delay and model selection using our best identified no delay pharmacokinetic model both indicated that the delay mechanism was not statistically justified and did not substantially improve model predictions.</p><p>Our final investigation explored parameter bounding techniques to identify parameter regions for which statistical model failure will not occur. When a model predicts a no probability of a diver experiencing decompression sickness for an exposure that is known to produce symptoms, statistical model failure occurs. Using a metric related to the instantaneous risk, we successfully identify regions where model failure will not occur and identify the boundaries of the region using a root bounding technique. Several models are used to demonstrate the techniques, which may be employed to reduce the difficulty of model optimization for future investigations.</p> / Dissertation

Resumo: Propósito: Investigar a efetividade da descompressão no tratamento inicial de ameloblastomas e os efeitos desse tipo de tratamento conservador nas características histopatológicas e de proliferação celular do tumor. Materiais e Métodos: Foram estudados retrospectivamente 8 pacientes portadores de ameloblastoma de mandíbula procedentes da Faculdade de Odontologia de Araçatuba-UNESP e do Hospital das Clínicas da FMUSP, sendo 4 ameloblastomas unicísticos e 4 multicísticos que tiveram como tratamento inicial pré-cirúrgico a descompressão. Foram avaliados o dados clínicos e imaginológicos antes e depois da descompressão. Foram definidos critérios para a indicação da descompressão. Fez-se também o estudo comparativo histopatológico antes e depois da descompressão. Os efeitos da descompressão sobre a proliferação celular do tumor foram investigados por meio da contagem de AgNORs e avaliação da expressão de PCNA e Ki-67. Resultados: Em todos os casos a descompressão foi efetiva promovendo considerável redução do tumor. O caráter cístico do tumor foi comprovado por punção aspirativa prévia em todos os pacientes. Aspecto radiográfico unilocular foi visto em 5 casos e multilocular com grande loja radiolúcida em 2. O período de descompressão foi de 5 a 12 meses e a técnica mostrou ser bem aceita pelo paciente, de baixo custo e de fácil execução. A avaliação comparativa histopatológica revelou que em alguns casos a descompresssão pode modificar o clássico padrão do epitélio odontogênico do ameloblastoma para um epitélio do tipo ameloblastomatoso com abrandamento dos critérios de Vickers & Gorlin. Não observamos significativa diferença na contagem do AgNOR e na expressão do PCNA e do Ki-67 do epitélio tumoral antes e depois da descompressão. Conclusão: Nossos resultados indicam que a descompressão é um valioso método no tratamento inicial de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Purpose: To investigate the effectiveness of decompression in ameloblastoma initial treatment and its action on histopathologic characteristics and cellular proliferation of the tumor. Materials e Methods: A retrospective study of 4 unicystic and 4 multicystic mandible ameloblastoma submitted to decompression was realized with. Clinical and radiologic informations before and after decompression were obtained from the records of the Faculty of Dentistry of Araçatuba, UNESP and of the Hospital das Clínicas of the School of Medicine, USP. Criterions for decompression indication were determined and a histopathologic comparative study before and after decompression was realized. The effect of decompression on cellular proliferation was investigated by AgNOR count and expression of PCNA and Ki-67 evaluation. Results: Decompression was effective in all the studied cases presenting a considerable decrease of the tumor. The cystic aspect was confirmed by previous aspirate punction. Unilocular radiologic aspect was observed in 5 cases and multilocular with great radiolucent region in 2 cases. The decompression period lasted from 5 to 12 months and the technique was well accepted by the patients, with low cost and easy accomplishment. In some cases the histopathological comparative evaluation showed an alteration of the classical odontogenic epithelium pattern of the ameloblastoma to an ameloblastomatous epithelium with lightening of Vickers & Gorlin criterions. Significative difference in the cellular proliferation to the tumoral epithelium was not observed between before and after the decompression. Conclusion: Our results consider decompression as a valuable method for initial treatment of unicystic and multicystic ameloblastoma with great cystic degeneration. It decreases the tumor size and increases the bone support reducing the necessity of mandibulectomy... (Complete abstract, click electronic address below) / Orientador: Norberto Perri Moraes / Coorientador: Marcelo Macedo Crivelini / Banca: Idelmo Rangel Garcia Júnior / Banca: Antônio Francisco Durighetto Júnior / Banca: Norberto Perri Moraes / Mestre

Real-time rendering of static volumetric data is generally known to be a memory and computationally intensive process. With the advance of graphic hardware, especially GPU, it is now possible to do this using desktop computers. However, with the evolution of real-time CT and MRI technologies, volumetric rendering is an even bigger challenge. The first one is how to reduce the data transmission between the main memory and the graphic memory. The second one is how to efficiently take advantage of the time redundancy which exists in the time-varying volumetric data. Most previous researches either focus on one problem or the other. In this thesis, we implemented a system which efficiently deals with both of the challenges. We proposed an optimized compression scheme that explores the time redundancy as well as space redundancy of time-varying volumetric data. The compressed data is then transmitted to graphic memory and directly rendered by GPU, so the data transfer between main memory and graphic memory is significantly reduced. With our implemented system, we successfully reduce more than half of the time of transferring the whole data directly. We also compare our proposed compression scheme with the one without exploiting time redundancy. The optimized compression scheme shows a reduce compression distortion over time. With usability, portability and extensibility in mind, the implemented system is also quite flexible.

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This thesis proposes an approach to improve test compression using sequential linear decompressors by using retained free variables. Sequential linear decompressors are inherently efficient and attractive for encoding test vectors with high percentages of don't cares (i.e., test cubes). The encoding of these test cubes is done by solving a system of linear equations. In streaming decompression, a fixed number of free variables are used to encode each test cube. The non-pivot free variables used in Gaussian Elimination are wasted when the decompressor is reset before encoding the next test cube which is conventionally done to keep computational complexity manageable. In this thesis, a technique for retaining the non-pivot free variables when encoding one test cube and using them in encoding the subsequent test cubes is explored. This approach retains most of the non-pivot free variables with a minimal increase in runtime for solving the equations. Also, no additional control information is needed. Experimental results are presented showing that the encoding efficiency and hence compression, can be significantly boosted. / text

No description available.

XML is a widely used data exchange format. The verbose nature of XML leads to the requirement to efficiently store and process this type of data using compression. Various general-purpose transforms and compression techniques exist that can be used to transform and compress XML data. More compact alternatives to XML data have been developed, namely JSON due to the verbosity of XML data. Similarly, there is a requirement to efficiently store and process SMILES data used in Chemoinformatics. General-purpose transforms and compressors can be used to compress this type of data to a certain extent, however, these techniques are not specific to SMILES data. The primary contribution of this research is to provide developers that use XML, JSON or SMILES data, with key knowledge of the best transformation techniques to use with certain types of data, and which compression techniques would provide the best compressed output size and processing times, depending on their requirements. The main study in this thesis, investigates the extent of which using data transforms prior to data compression can further improve the compression of XML and JSON data. It provides a comparative analysis of applying a variety of data transform and data transform variations, to a number of different types of XML and JSON equivalent datasets of various sizes, and applying different general-purpose compression techniques over the transformed data. A case study is also conducted, to investigate data transforms prior to compression to improve the compression of data within a data-specific domain.

Made available in DSpace on 2014-06-11T19:25:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-21Bitstream added on 2014-06-13T20:13:37Z : No. of bitstreams: 1 bernabe_dg_me_araca.pdf: 7019228 bytes, checksum: e0f61885765ce32b3656f184e94c9a2b (MD5) / Universidade Estadual Paulista (UNESP) / Propósito: Investigar a efetividade da descompressão no tratamento inicial de ameloblastomas e os efeitos desse tipo de tratamento conservador nas características histopatológicas e de proliferação celular do tumor. Materiais e Métodos: Foram estudados retrospectivamente 8 pacientes portadores de ameloblastoma de mandíbula procedentes da Faculdade de Odontologia de Araçatuba-UNESP e do Hospital das Clínicas da FMUSP, sendo 4 ameloblastomas unicísticos e 4 multicísticos que tiveram como tratamento inicial pré-cirúrgico a descompressão. Foram avaliados o dados clínicos e imaginológicos antes e depois da descompressão. Foram definidos critérios para a indicação da descompressão. Fez-se também o estudo comparativo histopatológico antes e depois da descompressão. Os efeitos da descompressão sobre a proliferação celular do tumor foram investigados por meio da contagem de AgNORs e avaliação da expressão de PCNA e Ki-67. Resultados: Em todos os casos a descompressão foi efetiva promovendo considerável redução do tumor. O caráter cístico do tumor foi comprovado por punção aspirativa prévia em todos os pacientes. Aspecto radiográfico unilocular foi visto em 5 casos e multilocular com grande loja radiolúcida em 2. O período de descompressão foi de 5 a 12 meses e a técnica mostrou ser bem aceita pelo paciente, de baixo custo e de fácil execução. A avaliação comparativa histopatológica revelou que em alguns casos a descompresssão pode modificar o clássico padrão do epitélio odontogênico do ameloblastoma para um epitélio do tipo ameloblastomatoso com abrandamento dos critérios de Vickers & Gorlin. Não observamos significativa diferença na contagem do AgNOR e na expressão do PCNA e do Ki-67 do epitélio tumoral antes e depois da descompressão. Conclusão: Nossos resultados indicam que a descompressão é um valioso método no tratamento inicial de... / Purpose: To investigate the effectiveness of decompression in ameloblastoma initial treatment and its action on histopathologic characteristics and cellular proliferation of the tumor. Materials e Methods: A retrospective study of 4 unicystic and 4 multicystic mandible ameloblastoma submitted to decompression was realized with. Clinical and radiologic informations before and after decompression were obtained from the records of the Faculty of Dentistry of Araçatuba, UNESP and of the Hospital das Clínicas of the School of Medicine, USP. Criterions for decompression indication were determined and a histopathologic comparative study before and after decompression was realized. The effect of decompression on cellular proliferation was investigated by AgNOR count and expression of PCNA and Ki-67 evaluation. Results: Decompression was effective in all the studied cases presenting a considerable decrease of the tumor. The cystic aspect was confirmed by previous aspirate punction. Unilocular radiologic aspect was observed in 5 cases and multilocular with great radiolucent region in 2 cases. The decompression period lasted from 5 to 12 months and the technique was well accepted by the patients, with low cost and easy accomplishment. In some cases the histopathological comparative evaluation showed an alteration of the classical odontogenic epithelium pattern of the ameloblastoma to an ameloblastomatous epithelium with lightening of Vickers & Gorlin criterions. Significative difference in the cellular proliferation to the tumoral epithelium was not observed between before and after the decompression. Conclusion: Our results consider decompression as a valuable method for initial treatment of unicystic and multicystic ameloblastoma with great cystic degeneration. It decreases the tumor size and increases the bone support reducing the necessity of mandibulectomy... (Complete abstract, click electronic address below)

Orientador: Marcio de Moraes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T00:42:43Z (GMT). No. of bitstreams: 1 MauretteO¿Brien_PaulEdward_M.pdf: 2138527 bytes, checksum: 184b6be2a89636c5de2b0ea675777d7a (MD5) Previous issue date: 2004 / Resumo: O propósito deste estudo foi avaliar retrospectivamente os casos de queratocistos odontogênicos (QO) tratados pela Área de Cirurgia Buco-Maxilo-Facial da Faculdade de Odontologia de Piracicaba da Universidade Estadual de Campinas (FOP-Unicamp), entre os anos 1995 e 2004. Foram avaliadas as características clínicas, histológicas e a eficácia do protocolo de tratamento em 28 pacientes com diagnóstico histológico de queratocisto odontogênico. Observou-se maior prevalência em mulheres (67,9%) de cor branca (57,1%), com idade média de 30 anos. A maioria das lesões estavam localizadas na região de ângulo e ramo mandibular (53,3%) e tinham padrão histológico paraqueratinizado (70%). Do total dos 28 pacientes, 13 (46,4%) apresentavam dente incluso envolvido na lesão. Inicialmente todos os pacientes foram submetidos a biópsia e tratados principalmente por descompressão e posterior curetagem da lesão remanescente (67,85%). O tempo médio de descompressão foi de 9,27 meses. Houve recorrência em 4 pacientes (14,3%), os quais tinham sido tratados com descompressão e curetagem (2 casos) ou unicamente com descompressão (2 casos). Todos os casos de recorrência foram tratados por meio de enucleação e curetagem associado a ostectomia periférica da cavidade óssea remanescente. O tempo médio de proservação de todos os pacientes da amostra foi de 24 meses, (mais ou menos 9,74). De acordo com os resultados podemos concluir que, dentro das características da amostra atendida, os pacientes são em sua maioria, mulheres adultas de cor branca, tratadas principalmente por meio de descompressão da lesão e apresentando taxas de recorrência similares à relatadas na literatura, demonstrando que o tratamento conservador do queratocisto odontogênico por meio do protocolo utilizado mostrou-se eficaz, de baixa morbidade e com índices de recorrências dentro da média relatada na literatura. No entanto, é necessário a contínua proservação buscando os resultados em longo prazo / Abstract: The aim of our study was to retrospectively evaluate all odontogenic keratocysts (OKC) cases treated in the Oral and Maxillofacial Surgery Department of Piracicaba Dental School at Campinas State University in Sao Paulo, Brazil between 1995 and 2004. This study evaluated clinical and histological characteristics of 28 patients all diagnosed with OKC by histopathology analysis and compared the data with that published in the literature. OKC was more prevalent in white (57.1%) and young (average age 30 years) females (67.9%). Most of the lesions (53.3%) occurred in the angle of the mandible and mandibular ramus. The most common histological pattern of OKC was parakeratinazed (70%) and 13 (46.4%) out of 28 patients presented impacted teeth associated with the lesion. Initial biopsy was performed in all patients and all cases were treated according to the Department of Oral and Maxillofacial Surgery Protocol, which consists mainly of decompression followed by curettage of the remaining lesion. The mean time for decompression was 9.27 months. Recurrence occurred in 4 patients (14.3%), who were initially treated with decompression and curettage (2 cases), or with decompression only (2 cases). All recurrent cases were submitted to enucleation and curettage of the remaining bone cavity. The average follow-up time for the 28 cases was 24 months (more or less 9,74). According to these results, we can conclude that adult white females treated for OKC with decompression, present similar recurrence rates to those reported in the literature. This Department of Oral and Maxillofacial Surgery¿s treatment protocol for OKC offers a conservative and effective option with low morbidity and similar recurrence rates to those reported in the literature. However, a long term follow-up is necessary to confirm these conclusions / Mestrado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Mestre em Clínica Odontológica