993 resultados para 3D dose distribution


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A hanseníase, doença crônica, granulomatosa, infecto-contagiosa, transmitida pelo Mycobacterium leprae, ainda se mantém prevalente nos dias atuais, principalmente em países subdesenvolvidos e a sua forma paucibacilar com lesão única, vem sendo tratada através da administração de rifampicina (600mg), ofloxacina (400mg) e minociclina (100mg), em dose única (esquema ROM). Assim, o objetivo deste trabalho foi investigar a correlação dose/concentração plasmática versus alterações bioquímicas na administração da rifampicina, ofloxacina e minociclina a ratos machos Wistar, em regime de dose única em mono e politerapia. Concluímos que a rifampicina e a ofloxacina sofreram um aumento na concentração plasmática quando administrados em politerapia, enquanto que a minociclina sofreu uma redução, provavelmente por interferências na biotransformação e excreção. Constatamos através das análises bioquímicas que a rifampicina provavelmente é a responsável por alterações hepáticas e renais, e que as interações medicamentosas envolvendo o fármaco exigem estudos individualizados principalmente quando o fármaco é usado associado a ofloxacina e minociclina.

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Two mucocutaneous leishmaniasis cases resistant to therapy are reported here. After the failure of initial therapies (antimony, amphotericin B and/or pentamidine) patients received a low-dose schedule: one ampoule of meglumine antimoniate (405mg of pentavalent antimony [Sb v]) by intramuscular injection, three times a week until complete healing of the lesions. One patient was cured with a total of 30 ampoules in 10 weeks and the other received 36 ampoules in 12 weeks. Both remain clinically cured after one year of follow-up.

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Some epidemiological characteristics of head lice, Pediculus capitis, were studied using two procedures: cut hair analysis and head inspection. Higher prevalence rates were observed in the middle and at the end of the school terms. Both procedures indicated that children were the main reservoir for this type of pediculosis in Uberlândia.

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Breast cancer is the most common cancer among women, being a major public health problem. Worldwide, X-ray mammography is the current gold-standard for medical imaging of breast cancer. However, it has associated some well-known limitations. The false-negative rates, up to 66% in symptomatic women, and the false-positive rates, up to 60%, are a continued source of concern and debate. These drawbacks prompt the development of other imaging techniques for breast cancer detection, in which Digital Breast Tomosynthesis (DBT) is included. DBT is a 3D radiographic technique that reduces the obscuring effect of tissue overlap and appears to address both issues of false-negative and false-positive rates. The 3D images in DBT are only achieved through image reconstruction methods. These methods play an important role in a clinical setting since there is a need to implement a reconstruction process that is both accurate and fast. This dissertation deals with the optimization of iterative algorithms, with parallel computing through an implementation on Graphics Processing Units (GPUs) to make the 3D reconstruction faster using Compute Unified Device Architecture (CUDA). Iterative algorithms have shown to produce the highest quality DBT images, but since they are computationally intensive, their clinical use is currently rejected. These algorithms have the potential to reduce patient dose in DBT scans. A method of integrating CUDA in Interactive Data Language (IDL) is proposed in order to accelerate the DBT image reconstructions. This method has never been attempted before for DBT. In this work the system matrix calculation, the most computationally expensive part of iterative algorithms, is accelerated. A speedup of 1.6 is achieved proving the fact that GPUs can accelerate the IDL implementation.

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Nowadays, existing 3D scanning cameras and microscopes in the market use digital or discrete sensors, such as CCDs or CMOS for object detection applications. However, these combined systems are not fast enough for some application scenarios since they require large data processing resources and can be cumbersome. Thereby, there is a clear interest in exploring the possibilities and performances of analogue sensors such as arrays of position sensitive detectors with the final goal of integrating them in 3D scanning cameras or microscopes for object detection purposes. The work performed in this thesis deals with the implementation of prototype systems in order to explore the application of object detection using amorphous silicon position sensors of 32 and 128 lines which were produced in the clean room at CENIMAT-CEMOP. During the first phase of this work, the fabrication and the study of the static and dynamic specifications of the sensors as well as their conditioning in relation to the existing scientific and technological knowledge became a starting point. Subsequently, relevant data acquisition and suitable signal processing electronics were assembled. Various prototypes were developed for the 32 and 128 array PSD sensors. Appropriate optical solutions were integrated to work together with the constructed prototypes, allowing the required experiments to be carried out and allowing the achievement of the results presented in this thesis. All control, data acquisition and 3D rendering platform software was implemented for the existing systems. All these components were combined together to form several integrated systems for the 32 and 128 line PSD 3D sensors. The performance of the 32 PSD array sensor and system was evaluated for machine vision applications such as for example 3D object rendering as well as for microscopy applications such as for example micro object movement detection. Trials were also performed involving the 128 array PSD sensor systems. Sensor channel non-linearities of approximately 4 to 7% were obtained. Overall results obtained show the possibility of using a linear array of 32/128 1D line sensors based on the amorphous silicon technology to render 3D profiles of objects. The system and setup presented allows 3D rendering at high speeds and at high frame rates. The minimum detail or gap that can be detected by the sensor system is approximately 350 μm when using this current setup. It is also possible to render an object in 3D within a scanning angle range of 15º to 85º and identify its real height as a function of the scanning angle and the image displacement distance on the sensor. Simple and not so simple objects, such as a rubber and a plastic fork, can be rendered in 3D properly and accurately also at high resolution, using this sensor and system platform. The nip structure sensor system can detect primary and even derived colors of objects by a proper adjustment of the integration time of the system and by combining white, red, green and blue (RGB) light sources. A mean colorimetric error of 25.7 was obtained. It is also possible to detect the movement of micrometer objects using the 32 PSD sensor system. This kind of setup offers the possibility to detect if a micro object is moving, what are its dimensions and what is its position in two dimensions, even at high speeds. Results show a non-linearity of about 3% and a spatial resolution of < 2µm.

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Climate change is emerging as one of the major threats to natural communities of the world’s ecosystems; and biodiversity hotspots, such as Madeira Island, might face a challenging future in the conservation of endangered land snails’ species. With this thesis, progresses have been made in order to properly understand the impact of climate on these vulnerable taxa; and species distribution models coupled with GIS and climate change scenarios have become crucial to understand the relations between species distribution and environmental conditions, identifying threats and determining biodiversity vulnerability. With the use of MaxEnt, important changes in the species suitable areas were obtained. Laurel forest species, highly dependent on precipitation and relative humidity, may face major losses on their future suitable areas, leading to the possible extinction of several endangered species, such as Leiostyla heterodon. Despite the complexity of the biological systems, the intrinsic uncertainty of species distribution models and the lack of information about land snails’ functional traits, this analysis contributed to a pioneer study on the impacts of climate change on endemic species of Madeira Island. The future inclusion of predictions of the effect of climate change on species distribution as part of IUCN assessments could contribute to species prioritizing, promoting specific management actions and maximizing conservation investment.

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The results discussed in this thesis originated the following communications in International and National congresses: Sacramento JF, Coelho JC, Melo BF, Guarino MP and Conde SV. (2014) Assessment of caffeine dose and time of administration required for resetting insulin sensitivity in high sucrose diet in rats. 50th Meeting of EASD (European Association for the study of Diabetes), 14-19 September, Vienna, Austria Coelho JC, Melo BF, Sacramento JF, Guarino MP and Conde SV (2014). Establishing the caffeine dose that chronically restores insulin sensitivity in animal model of prediabetes. Fundação Astrazeneca Innovate Competition, iMed conference 6.0®, 10-12 October, Lisboa, Portugal Also, during the last year I was involved in other ongoing projects that originated the following communications: Coelho JC, Melo BF, Sacramento JF, Ribeiro MJ, Guarino MP and Conde SV (2014). Are the effects of carotid sinus nerve resection on insulin sensitivity mediated by an increase in Glut4 expression in skeletal muscle?. XLIV Reunião Anual da Sociedade Portuguesa de Farmacologia, XXXII Reunião de Farmacologia Clínica e XIII Reunião de Toxicologia, 5-7 February, Coimbra, Portugal Sacramento JF, Rodrigues T, Coelho JC, Matafome P, Ribeiro MJ, Seiça RM, Guarino MP, Conde SV (2014). Elucidating the mechanism by which carotid sinus nerve resection restores insulin sensitivity in pre-diabetes animal models. International Society for Arterial Chemoreception (ISAC) XIX University of Leeds, 29th June - 3rd July, Leeds, United Kingdom

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Micro/nano wrinkled patterns on cross-linked urethane/urea polymeric flexible free standing films with two soft segments, polypropylene oxide and polybutadiene, can be induced by UV-irradiation. The ability to write/erase these 3D structures, in a controlled manner, is the main focus of this work. The imprinting of the wrinkled structures was accomplished by swelling in an appropriate solvent followed by drying the membranes after the cross-linking process and UV irradiation. The surface tailoring of the elastomeric membranes was imaged by optical microscopy, scanning electronic microscopy and by atomic force microscopy. To erase the wrinkled structures the elastomers were swollen. The swelling as well as the sol/gel fraction and the UV radiation were tuned in order to control the wrinkles characteristics. It was found that the wrinkles wavelength, in the order of microns (1±0,25μm), was stamped by the UV radiation intensity and exposure time while the wrinkles' amplitude, in the order of nanometers (150-450 nm), was highly dependent on the swelling and sol/gel fraction. A prototype for volatile organic compounds detection was developed taking advantage of the unique 3D micro/nano wrinkles features.

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INTRODUCTION: Human T cell lymphotropic virus types 1 and 2 (HTLV-1/2) are endemic in Brazil and are screened for in transfusion services since 1993. This study evaluated the evolution of the prevalence of HTLV-1 and 2 in blood donors of the Hemominas Foundation from 1993 to 2007, and its geographical distribution in State of Minas Gerais, Brazil. METHODS: The Hemominas Foundation is a centralized blood center in Minas Gerais, Brazil. The sources of data were the Hemominas Foundation Technical Bulletin and files from the centralized serological laboratory. Donors were tested in the period using enzyme linked immuno sorbent assays (ELISA), followed by Western blot, when repeatedly reactive. The data were analyzed by EPIINFO 6.2 and TABWIN 3.5 softwares. RESULTS: The average seroprevalence in the period 1993-2007 was 0.1%. A steady decline occurred from 0.4% in 1993 to below 0.1% in 2002 and later, with a transient peak of 0.5% in 1994. HTLV reactivity distribution was asymmetrical in the state, with regions of higher prevalence, interspersed with low prevalence areas. Comparison of positive and negative donors verified that increasing age was proportional to virus positivity. Odds ratio for age ranged from 1.43 (30 to 39 years-old) to 3.09 (50 to 65 years-old). Women had a greater chance of being positive (OR-1.64), as previously described. CONCLUSIONS: Possible explanations for HTLV-1/2 prevalence decline are the exclusion of positive donors from the donor pool, an increase in repeat donors and ELISA test improvement, with reduction in the number of false positive results.

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INTRODUÇÃO: Em 1997, após a realização de estudo multicêntrico, duplo cego e randomizado, em nove centros de tratamento de hanseníase na Índia, o Ministério da Saúde adotou o esquema alternativo dose única ROM para casos de lesão única, paucibacilar, sem nervo periférico afetado, índice baciloscópico negativo, em Centros de Referência da doença no Brasil. O estudo se propôs a avaliar a efetividade do esquema ROM em pacientes tratados no período de 1997 a 1999 no Serviço de Dermatologia da Santa Casa de Vitória. MÉTODOS: Foram selecionados e tratados com o esquema ROM, 54 pacientes das formas indeterminada e tuberculóide. Estes pacientes foram convocados de março a outubro de 2006 para reavaliação clínica. RESULTADOS: Vinte e nove pacientes avaliados (85,2%; IC95%: 70-100,4) estavam curados, cinco (14,7%; IC95%: 7,4-22,0) recidivaram e 20 pacientes não retornaram; porém, não havia outra notificação de reingresso ao tratamento no banco de dados da Secretaria Estadual de Saúde. CONCLUSÕES: O estudo evidenciou taxa de cura de 90,8% e taxa bruta de recidiva de 9,2%, após período de sete a nove anos da dose ROM. O tratamento alternativo ROM demonstrou melhor efetividade para lesão única menor que quatro centímetros e aparecimento há menos de cinco anos.

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INTRODUCTION: Epidemiological studies concerning HCV genotypic distribution in the Brazilian Amazon are scarce. Thus, this study determined the patterns of distribution of HCV genotypes among different exposure categories in the State of Pará, Brazilian Amazon. METHODS: A cross-sectional study was conducted on 312 HCV-infected individuals belonging to different categories of exposure, who were attended at the HEMOPA, CENPREN and a private hemodialysis clinic in Belém. They were tested for HCV antibodies using an immunoenzymatic test, RNA-HCV, using real-time PCR and HCV genotyping through phylogenetic analysis of the 5' UTR. The population groups were epidemiologically characterized according to data collected in a brief interview or medical consultation. RESULTS: Genotype 1 predominated in all the different categories of HCV exposure. HCV genotypic distribution among blood donors comprised genotypes 1 (94%) and 3 (6%). All patients with chronic hematologic diseases had HCV genotype 1. The genotypic distribution in illicit-drug users comprised genotypes 1 (59.6%) and 3 (40.4%). In patients under hemodialysis, genotypes 1 (90.1%), 2 (3.3%), and 3 (6.6%) were detected. Finally, the frequency of genotypes 1 and 3 was significantly different between the groups: BD and DU, PUH and DU, PUH and PCHD and PCHD and DU. CONCLUSIONS: The genotypic frequency and distribution of HCV in different categories of exposure in the State of Pará showed a predominance of genotype 1, regardless of the possible risk of infection.

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RESUMO - Numa época de constrangimento orçamental, os hospitais do SNS vêm-se na obrigação de melhorar a eficiência de utilização dos recursos disponíveis, por forma a contribuir para o seu equilíbrio financeiro. Cabe a cada prestador analisar a sua posição, avaliar as suas oportunidades e adoptar estratégias que a curto, médio ou longo prazo se traduzam numa efetiva melhoria na eficiência. A análise e o controlo do desperdício associado à prestação de cuidados de saúde apresentam-se, globalmente, como uma dessas oportunidades. Neste trabalho são exploradas oportunidades de redução de desperdício em medicamentos, numa perspectiva meramente operacional, a nível das funções desempenhadas pelos Serviços Farmacêuticos (SF). No hospital em estudo acompanhou-se as diferentes linhas de produção dos SF, nomeadamente as tarefas envolvidas no processo de Distribuição Individual Diária em Dose Unitária, na distribuição de medicamentos para o Serviço de Urgências (SU) e na preparação de citotóxicos e imunomoduladores para o Hospital de Dia de Oncologia. Durante o ano de 2013, os SF devolveram aos fornecedores 0,07% e abateram 0,05% da despesa em medicamentos. A análise dos erros de medicação registados reflete o tipo de distribuição adotado para a maioria dos serviços de internamento do hospital. As melhorias encontradas a este nível passam pelo reforço de recursos humanos a desempenhar as tarefas de dispensa de medicamentos mas também pela implementação de uma cultura de registo de erros e acidentes, baseada no sistema de informação, para que se consiga quantificar o desperdício associado e agir com vista à optimização do circuito. A relação entre o método de distribuição adotado para o SU e a utilização do medicamento neste serviço foi apenas investigada para os medicamentos de registo individual de administração. Foi determinado um índice de eficiência de utilização de 67,7%, entre o dispensado e o administrado. Às discrepâncias encontradas está associado um custo de 32 229,6 € para o ano de 2013. Constatou-se também que, a nível do consumo de citotóxicos e imunomoduladores houve, durante o mês de abril de 2013, um índice de desperdício médio de 14,7%, entre o prescrito e o consumido, que se traduziu num custo do desperdício mensal de 13 070,9 €. Com base no desperdício mensal estimou-se que o desperdício anual associado à manipulação de citotóxicos e imunomoduladores deverá corresponder a 5,5% da despesa anual do serviço com estes medicamentos. Não obstante as limitações encontradas durantes o trabalho, e parte do desperdício apurado ser inevitável, demonstrou-se que o desperdício em medicamentos pode traduzir-se numa fatia não negligenciável mas controlável da despesa do hospital em estudo. No seguimento do seu conhecimento, a sua contenção pode ter um impacto na redução de despesa a curto-médio prazo, sem a necessidade de racionamento da utilização de medicamentos e sem alterar os padrões de qualidade assistencial exigidos pela tutela e pelos doentes. Por último, são apresentadas recomendações para a redução do desperdício em medicamentos, adequadas a cada uma das dimensões analisadas.

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INTRODUCTION: In this study, we aimed at identifying Candida isolates obtained from blood, urine, tracheal secretion, and nail/skin lesions from cases attended at the Hospital Universitário de Londrina over a 3-year period and at evaluating fluconazole susceptibilities of the isolates. METHODS: Candida isolates were identified by polymerase chain reaction (PCR) using species-specific forward primers. The in vitro fluconazole susceptibility test was performed according to EUCAST-AFST reference procedure. RESULTS: Isolates were obtained from urine (53.4%), blood cultures (19.2%), tracheal secretion (17.8%), and nail/skin lesions (9.6%). When urine samples were considered, prevalence was similar in women (45.5%) and in men (54.5%) and was high in the age group >61 years than that in younger ones. For blood samples, prevalence was high in neonates (35%) and advanced ages (22.5%). For nail and skin samples, prevalence was higher in women (71.4%) than in men (28.6%). Candida albicans was the most frequently isolated in the hospital, but Candida species other than C. albicans accounted for 64% of isolates, including predominantly Candida tropicalis (33.2%) and Candida parapsilosis (19.2%). The trend for non-albicans Candida as the predominant species was noted from all clinical specimens, except from urine samples. All Candida isolates were considered susceptible in vitro to fluconazole with the exception of isolates belonging to the intrinsically less-susceptible species C. glabrata. CONCLUSIONS: Non-albicans Candida species were more frequently isolated in the hospital. Fluconazole resistance was a rare finding in our study.

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A Engenharia de Tecidos surge da necessidade recorrente de regenerar ou recriar órgãos e tecidos danificados devido a vários tipos de trauma. A carência de funcionalidades resultante pode ser resolvida através da implantação de substitutos bio-sintéticos. O presente trabalho consiste na produção de matrizes porosas 3D baseadas em réplicas invertidas de cristais coloidais com futura aplicação em substituintes ósseos sintéticos para fraturas de não-união. O substituinte ósseo consiste numa estrutura denominada Inverse colloidal crystal (ICC), em que a sua organização singular resulta numa homogénea proliferação celular e num aumento das propriedades mecânicas, quando comparada com outros substituintes. O primeiro passo para a obtenção desta estrutura é a produção de microesferas de poliestireno, por uma técnica baseada em microfluídica. Posteriormente as microesferas são empacotadas resultando numa estrutura coesa com ligações entre microesferas vizinhas. O preenchimento dos espaços vazios entre microesferas pelo biomaterial pretendido e posterior remoção das microesferas dá origem à estrutura porosa do ICC. ICCs poliméricos (ϕCs = 1,00) e compósitos (ϕCs = 0,86 e ϕHA = 0,14; ϕCs = 0,67 e ϕHA = 0,33; ϕCs = ϕHA = 0,50) são produzidos e as suas propriedades mecânicas são testadas através de ensaios de compressão e comparadas com outros substituintes sintéticos. Para avaliação do comportamento dos materiais em contacto com meio biológico, foram realizados testes de citotoxicidade que revelaram uma viabilidade celular acima dos 80% em todos os ICCs.