Doctor of Philosophy / Department of Mechanical and Nuclear Engineering / Douglas S. McGregor / The microstructured semiconductor neutron detector (MSND) was investigated and previous designs were improved and optimized. In the present work, fabrication techniques have been refined and improved to produce three-dimensional microstructured semiconductor neutron detectors with reduced leakage current, reduced capacitance, highly anisotropic deep etched trenches, and increased signal-to-noise ratios. As a result of these improvements, new MSND detection systems function with better gamma-ray discrimination and are easier to fabricate than previous designs. In addition to the microstructured diode fabrication improvement, a superior batch processing backfill-method for 6LiF neutron reactive material, resulting in a nearly-solid backfill, was developed. This method incorporates a LiF nano-sizing process and a centrifugal batch process for backfilling the nanoparticle LiF material. To better transition the MSND detector to commercialization, the fabrication process was studied and enhanced to better facilitate low cost and batch process MSND production. The research and development of the MSND technology described in this work includes fabrication of variant microstructured diode designs, which have been simulated through MSND physics models to predict performance and neutron detection efficiency, and testing the operational performance of these designs in regards to neutron detection efficiency, gamma-ray rejection, and silicon fabrication methodology. The highest thermal-neutron detection efficiency reported to date for a solid-state semiconductor detector is presented in this work. MSNDs show excellent neutron to gamma-ray (n/γ) rejection ratios, which are on the order of 106, without significant loss in thermal-neutron detection efficiency. Individually, the MSND is intrinsically highly sensitive to thermal neutrons, but not extrinsically sensitive because of their small size. To improve upon this, individual MSNDs were tiled together into a 6x6-element array on a single silicon chip. Individual elements of the array were tested for thermal-neutron detection efficiency and for the n/γ reject ratio. Overall, because of the inadequacies and costs of other neutron detection systems, the MSND is the premier technology for many neutron detection applications.

Dizertační práce se zabývá mechanismy mazání v náhradách kyčelního kloubu. Byla provedena systematická studie formování proteinového filmu při zahrnutí různých materiálů a provozních podmínek. Hlavní pozornost je přitom věnována roli jednotlivých proteinů obsažených v synoviální kapalině při současné přítomnosti dalších proteinů. Jelikož metody aplikované v předchozích studiích neumožňovaly separovat jednotlivé složky maziva, byla vyvinuta optická měřící metoda na principu fluorescenční mikroskopie. Z důvodu verifikace metody byly provedeny dvě nezávislé studie zaměřené na měření tloušťky mazacího filmu a dělení maziva na výstupu mazaného kontaktu. Z důvodu určitých limitací fluorescenční mikroskopie byla dále využita i metoda optické interferometrie, jejíž využití je ilustrováno ve studii zabývající se formováním mazacího filmu v náhradách kyčelního klubu při uvažování reálné konformity třecích povrchů. Závěrečná část práce představuje nový metodologický přístup založený na in situ pozorování kontaktní oblasti umožňující popsat roli jednotlivých proteinů ve vztahu k vývoji tloušťky mazacího filmu. Práce obsahuje originální výsledky, které přináší nové poznání v oblasti biotribologie náhrad kyčelního kloubu vedoucí k dalšímu vývoji implantátů při snaze zabránit jejich selhání v důsledku omezené životnosti.

Le cancer du sein est un problème majeur de santé publique en Amérique Latine (AL). Il a été montré que le surpoids, l'obésité, et les traitements hormonaux sont des facteurs de risque majeurs pour le développement du cancer du sein. Toutefois ces associations restent incertaines dans les populations d'AL. Le but de cette Thèse est donc de contribuer à combler ces lacunes en développant des études sur l'impact du surpoids et de l'obésité, ainsi que des traitements hormonaux, dans des populations latino-américaines. Nous avons donc utilisé les données originales d'une étude cas-témoins basée sur la population Mexicaine. Préalablement à cette étude, nous avons conduit une méta-analyse sur l'obésité et le cancer du sein chez la femme pré-ménopausée à travers le monde. Cette méta-analyse montre qu'à l'exception des Asiatiques, les personnes qui ont un indice de masse corporelle (IMC) élevé ont un risque diminué de cancer du sein pré-ménopausique tandis que celles qui ont un rapport tour de taille/hanches (RTH) élevé ont un risque du cancer du sein accru. L'étude cas-témoins montre une association inverse entre l'IMC élevé et le risque de cancer du sein en pré-ménopause tandis qu'en post ménopause aucune association n'a été observée. Cependant, le tour de taille, de hanche, et le RTH s'avèrent également inversement associés au risque de cancer du sein en pré et post-ménopause. D'autre part, l'augmentation de la silhouette tout au long de la vie est associée à un risque accru de cancer du sein. L'utilisation des traitements hormonaux substitutifs à la ménopause est également associée à un risque accru de cancer du sein. Cette étude apporte de nouvelles informations sur l'impact de ces facteurs sur le risque de cancer du sein / Breast cancer is a major public health problem in Latin America (LA). It has been shown that, overweight, obesity, and hormonal treatments are major risk factors for breast cancer development. However, these associations remain uncertain among Latin American populations. The aim of this thesis is to contribute to fill these gaps by developing studies on the impact of overweight and obesity, and hormonal treatments in Latin American populations. We used the original data from a multi-center population-based case–control study conducted in Mexico. Prior to this study, we conducted a dose-response meta-analysis on obesity and premenopausal breast cancer. This meta-analysis shows that, in the exception of Asians, increase in body mass index was inversely associated with the risk of premenopausal breast cancer; whereas, increase in waist-to-hip ratio are associated with an increase of this risk. The results of the case-control study show an inverse association between high BMI and the risk of breast cancer in pre-menopausal women, whereas no association was observed among post-menopausal. However, other anthropometric measures (waist and hip circumference, and waist hip ratio) are also inversely associated with risk of breast cancer in pre and post-menopausal women. Further analysis of body shape evolution throughout life showed significant increase in risk of breast cancer among women with increasing silhouettes size over time. With regards to menopausal hormone replacement therapy, users have a significant increased risk of breast cancer. This study provides new information about the effects of these factors on breast cancer risk, which may be of relevance for the population of LA as a whole

No description available.

L’insuffisance rénale chronique (IRC) terminale est une situation peu fréquente chez l’enfant mais a des conséquences importantes sur la survie et la qualité de vie. De nos jours, la majorité des enfants en IRC terminale en Europe vont recevoir une greffe de rein après un traitement de suppléance par dialyse ou de manière préemptive après un traitement conservateur de l’insuffisance rénale. Les objectifs de cette thèse sont de décrire l’épidémiologie de l’IRC chez l’enfant, d’évaluer les différences de pratiques et d’accès à la greffe rénale entre pays Européens, et d’investiguer le devenir clinique après transplantation, notamment la survie du greffon, la croissance, et la récidive de la maladie initiale sur le greffon. Premièrement, une revue de littérature sur l’épidémiologie de l’IRC chez l’enfant a été réalisée. Deuxièmement, nous avons mis en évidence par une enquête d’importantes variations de pratiques, de politiques d’allocation des greffons rénaux et d’accès à la greffe rénale pédiatrique à travers l’Europe. Des facteurs tels que le taux de greffe avec donneur vivant, la priorité nationale donnée aux enfants pour les donneurs décédés, ou un indicateur de richesse tel que le produit intérieur brut étaient associés à un meilleur accès à la greffe par pays. Troisièmement, l’étude du devenir après greffe par des études observationnelles a montré une amélioration de de la survie des greffons et de la taille à l’âge adulte après IRC terminale dans l’enfance. En utilisant l’oxalose comme exemple de maladie à haut risque de révidive, nous avons trouvé que le pronostic des enfants atteints d’oxalose en IRCT s’est amélioré au cours du temps. Il a été possible de déterminer quelles pratiques cliniques sont associées avec le meilleur devenir. L’ensemble de ces résultats suggère une augmentation de la prévalence et une meilleure prise en charge des enfants transplantés du rein en Europe. / Although end-stage renal disease (ESRD) is a rare condition in children, it has major consequences on their survival and quality of life. Most children with ESRD in Europe nowadays receive a renal transplant after variable periods of renal replacement therapy (RRT) with dialysis, or preemptively after conservative treatment of chronic kidney disease (CKD). The objectives of this thesis are to describe the epidemiology of CKD in children, to evaluate the differences of practices and access to transplant in Europe, and to investigate post transplant outcomes including graft survival, final height and disease recurrence. First, a literature review of the available data on pediatric CKD epidemiology was performed. Second, we analyzed the differences in transplantation practices, kidney allocation policies and access to transplantation between European countries in a survey study. Living donor transplant rate, national priority given to children, and an economic indicator like gross domestic product were found to be associated with a better access to transplantation by country. Third, we assessed post transplantation outcomes in longitudinal observational studies, including data from the European registry. We showed an improvement of graft survival and of adult height after childhood RRT over the years. Using oxalosis as an example of a rare disease with high risk of recurrence, we also found that the prognosis on RRT of children with such a disease improved over time. Some practices associated with better outcomes could be identified. Overall, our findings suggest an increasing prevalence and progress in the management of pediatric kidney transplant recipients in Europe.

Introdução: As mucopolissacaridoses (MPSs) são doenças de deposito lisossômico causadas por deficiências enzimáticas envolvidas na degradação das glicosaminoglicanas. O catabolismo das glicosaminoglicanas pode ser bloqueado isoladamente ou em combinações, podendo ocorrer o acúmulo de dermatan sulfato, heparan sulfato, queratan sulfato, e o acido hialurônico. Existem sete tipos de MPSs (tipos I, II, III, IV, VI, VII e IX) causados por onze deficiências enzimáticas conhecidas; o comprometimento multissistêmico progressivo é uma característica comum à maioria dos tipos. O espectro de manifestações neurológicas é amplo e o diagnóstico precoce de tais manifestações é fundamental para um melhor prognóstico. A terapia de reposição enzimática (TRE) é atualmente disponível para o tratamento de alguns tipos de MPS, entretanto não há evidências de melhorias dos sintomas neurológicos com o uso da TRE. Objetivo: O objetivo deste estudo foi descrever as alterações neurológicas e de neuroimagem nos diversos tipos de MPSs. Métodos: Vinte pacientes com diagnóstico de mucopolissacaridoses (MPS) foram incluídos no estudo e avaliados conforme o protocolo clínico e de neuroimagem pré-estabelecido. Os pacientes foram submetidos à ressonância magnética (RM) de crânio e coluna em aparelhos de 1,5 Tesla. Resultados: Dentre os 20 pacientes da amostra, dois pacientes apresentavam MPS I (10%), três MPS II (15%), nove MPS IV (45%) e seis MPS VI (30%). As idades variaram de três a 26 anos (12,5 ± 6,1) e 13 (65%) pacientes eram do sexo masculino. Os pacientes com MPSs tipo I e II apresentaram uma ampla diversidade clínica e de neuroimagem. Desde casos oligossintomáticos com exame neurológico normal até um atraso significativo do desenvolvimento neuropsicomotor (DNPM), com alterações cognitivas, motoras e sensitivas persistentes foram encontrados. Os exames de RM dos pacientes com MPSs I e II apresentaram alterações tais como espessamento da díploe, alargamento dos espaços perivasculares, dilatação ventricular e comprometimento da substância branca. Alterações degenerativas na coluna vertebral estiveram presentes em todos os pacientes com MPSs I e II, a despeito da maioria estar em regime de TRE. Compressão medular foi observada em apenas um paciente com MPS I e em nenhum paciente MPS II. Dos nove pacientes com MPS IV, dois apresentaram atraso do DNPM, um deles com alterações cognitivas persistentes; em todos os pacientes encontramos déficits motores e seis dentre os nove apresentaram alterções de sensibilidade profunda. Na RM dos pacientes com MPS IV, observamos hipoplasia do processo odontóide em todos os pacientes, e em oito foram encontrados sinais de compressão medular. Subluxação atlanto-axial foi vista em seis pacientes. Estenose do canal e lipomatose epidural também contribuíram para compressão medular, e três pacientes apresentaram dois níveis de compressão. Na RM do crânio, dois pacientes com MPS IV apresentaram alterações da substância branca. Nos pacientes com MPS VI, a cognição esteve preservada e alterações de reflexos e sensibilidade profunda foram encontradas. Além das alterações clássicas encontradas em outros pacientes com outros tipos de MPSs, a RM dos pacientes com MPS VI mostrou alterações morfológicas dos diâmetros do crânio e da fossa média. Mesmo apresentando força muscular normal, todos os pacientes com MPS VI apresentaram algum grau de compressão medular. Em quatro pacientes encontramos subluxação atlanto-axial e em três estenose do canal medular. Conclusões: A heterogeneidade clínica e de neuroimagem foram marcantes nos pacientes com MPSs tipos I e II. Alterações degenerativas do coluna vertebral estiveram presentes em todos os pacientes destes grupo, a despeito da TRE. Os achados clínicos e de neuroimagem nos pacientes com MPS IV reforçam o comprometimento primário do sistema nervoso central neste tipo de MPS. Além disso, os efeitos secundários da doença sobre o medula requerem avaliação neurológica e RM da coluna total periodicamente. Nos pacientes com MPS VI, apesar do exame clínico mostrar apenas alterações sutis, o comprometimento do neuroeixo foi um achado universal pela RM, demonstrando a necessidade de seguimento radiológico mesmo em pacientes oligossintomáticos em regime de TRE / Introduction: Mucopolysaccharidosis (MPS) are lisosomal storage disorders caused by deficiencies of glycosaminoglycans catabolism enzymes, leading to deposition of mucopolysaccharides; over time, there is cellular damage affecting several organs and systems. There are seven distinct phenotypes of MPS (types I, II, III, IV, VI, VII e IX) with eleven known enzymatic defects, which may result in accumulation of dermatan sulfate, heparan sulfate, queratan sulfate, and hyaluronic acid. Neurological manifestations are broad, and an early detection of these manifestations is essential to ensure a better prognosis of MPS patients. Enzymatic replacement therapy (ERT) is currently available to treat some types of MPS, albeit there is no evidence of direct neurological improvement with ERT. Objective: The objective of this study was to describe the clinical neurological abnormalities and neuroimaging findings in a sample of patients with diagnosis of MPS. Methods: Twenty patients previously diagnosed with distinct types of MPS were enrolled in the clinical and MRI protocol. Brain and spinal cord MRI were performed in 1.5 Tesla machines. Results: Amongst the 20 patients, two had diagnosis of MPS I (10%), three had MPS II (15%), nine had MPS type IV (45%), and six had MPS type VI (30%). The ages ranged between three and 26 years-old (mean 12,5 ± 6,1) and 13 pacients (65%) were male. Clinical findings in patients with MPS I and II were broad, ranging from an unremarkable neurologic examination to severe milestones delay, and cognitive, motor, and sensitive impairment. Neuroimaging features in patients with MPS I and II showed diploe thickness, enlargement of perivascular spaces, hydrocephalus and white matter abnormalities. Degenerative abnormalities in the spine were present in all patients with MPS I and MPS II. On the other hand, spinal cord compression was found in only one patient with MPS I and in none of the MPS II patients. Among the nine MPS IV patients, two had delayed milestones and one of those exhibited persistent cognitive impairment. All patients with MPS IV had motor deficits and six of them presented impairment of deep sensory modalities. Neuroimaging of patients with MPS IV showed white matter abnormalities in two and spinal cord compression in eight patients, with three of them presenting two levels of spinal cord compression. The main mechanism of compression was atlantoaxial subluxation; in addition, other abnormalities such as spinal stenosis and epidural lipomatosis also contributed to spinal cord compression in MPS IV patients. Patients with MPS VI had preserved cognition, but sensory exam and deep tendon reflex were abnormal. Other than classical brain MRI abnormalities, patients with MPS type VI also presented with changes in the middle cranial fossa and increased anteroposterior skull diameter. Even though all six patients with MPS VI presented normal muscle strength, all of them had some degree of spinal cord compression; four patients had atlantoaxial subluxation and three had spinal stenosis. Conclusions: Clinical and neuroimaging heterogeneity was remarkable in patients with MPS types I and II. Degenerative features in vertebrae were found in all patients with MPS I and II, despite ERT. Our clinical and neuroimaging findings in patients with MPS IV support the central nervous system impairment in these patients; additionally, it was possible to understand the underlying spinal cord compression mechanisms in MPS. Although clinical abnormalities were not meaningful in patients with MPS VI, they presented significant MRI abnormalities despite ERT. Routine assessments including neurologic examination and spinal cord MRI is extremely important in MPS patients

INTRODUÇÃO: Após a cirurgia pancreática, a função exócrina é determinada pela extensão da ressecção e a quantidade de tecido pancreático remanescente, sendo recomendável a avaliação da insuficiência pancreática exócrina (IPE) em todos os pacientes. A reposição de enzimas pancreáticas é o pilar do tratamento da IPE, pois melhora a absorção de gordura, diminui os sintomas relacionados com a má absorção e melhora a qualidade de vida (QV). OBJETIVO: Sabendo que o ajuste da dose de enzimas pancreáticas é realizado com base nos sinais clínicos relatados pelo paciente, o presente estudo visa aprofundar a avaliação clínica destes e avaliar o atual protocolo de tratamento, mantendo ou melhorando a QV dos pacientes. MÉTODOS: Estudo transversal em que foram avaliados adultos com histórico de ressecção pancreática há 6 meses ou mais. No tempo 1 foi realizada avaliação nutricional antropométrica e recordatório alimentar, avaliação clínica de qualidade de vida (questionário SF-36), investigação hábitos intestinais e exames laboratoriais. No tempo 2 foi realizada nova consulta para discussão dos resultados e orientação nutricional individualizada. Para análise de correlações foi usado o teste de Pearson, para associações o teste de Fisher e para comparação de médias o teste Mann-Whitney. RESULTADOS: Foram avaliados 39 pacientes, 22 (56,4%) do sexo feminino; 33 (84,6%) >=60 anos; tempo pós operatório 14,1± 6,8 anos; exames bioquímicos: em todas as dosagens a maioria dos pacientes apresenta resultados dentro dos valores de referência, mas há alta prevalência de deficiência de vitaminas lipossolúveis; os pacientes têm bom estado nutricional já que grande parte apresenta eutrofia segundo o IMC (46,1%) e segundo a porcentagem de gordura (35,9%); no geral não relatam sintomas gastrointestinais adversos: 61,5% com fezes formadas, 53,8% sem dor abdominal, 84,6% sem esteatorreia; adequação no consumo de macronutrientes: 51,3% consumo adequado de carboidratos e lipídios, e 64,1% de consumo excessivo de proteínas; correlações positivas: a dose de enzimas se correlaciona com a dor (p= 0,004) e o IMC (p= 0,009), ou seja, pacientes que relatam mais dor e que pesam mais são os que recebem as maiores doses de enzimas pancreáticas; correlações negativas: capacidade funcional e parâmetros de avaliação nutricional como IMC (p=0,004), e porcentagem de gordura (p=0,028), e também parâmetros clínicos como a dose de enzimas (p=0,022) e o número de evacuações por dia (p=0,024); associações: a inadequação do consumo de lipídios na dieta está associada com importantes sintomas gastrointestinais como a consistência amolecida das fezes (p=0,005) e flatulência (p=0,012) e ressalta a importância da orientação nutricional aos pacientes em reposição de enzimas pancreáticas. CONCLUSÃO: A maioria dos pacientes apresentou bons resultados de exames bioquímicos, qualidade de vida, consumo de macronutrientes, estado nutricional e sintomas gastrointestinais. Observaram-se importantes correlações e associações que demonstram que o estado nutricional, o consumo alimentar e a dose de enzimas interferem nos sintomas gastrointestinais e na auto-percepção de qualidade de vida dos pacientes. Sendo assim, o atual protocolo é válido, mas deve ser associado a orientação nutricional individualizada / BACKGROUND: After pancreatic surgery, exocrine function is determined by the extent of resection and the amount of remaining pancreatic tissue, and all patients should be evaluated for exocrine pancreatic insufficiency (EPI). Pancreatic enzyme replacement is the mainstay of EPI treatment, since it improves fat absorption, reduces symptoms related to malabsorption and improves quality of life (QoL). OBJECTIVE: Knowing that the adjustment of pancreatic enzymes dose is based on the clinical signs reported by the patient, the present study aims to deepen the clinical evaluation and to evaluate the current protocol of treatment, maintaining or improving patients quality of life. METHODS: A cross-sectional study in which adults were evaluated 6 months or more after pancreatic resection. At time 1, anthropometric evaluation and food recall, clinical evaluation of quality of life (SF-36 questionnaire), intestinal habits and laboratory tests were performed. At time 2 a new consultation was conducted to discuss the results and to provide individualized nutritional guidance. For the correlations analysis the Pearson test was used, for associations the Fisher test and for comparison of means the Mann-Whitney test. RESULTS: 39 patients were evaluated, 22 (56.4%) female; 33 (84.6%) >= 60 years; Time after surgery 14.1 ± 6.8 years; Biochemical tests: at all dosages most patients present results within the reference values, but there is a high prevalence of fat-soluble vitamins deficiency; The patients have good nutritional status since a great part presents eutrophy according to the BMI (46.1%) and according to the percentage of body fat (35.9%); In general they do not report adverse gastrointestinal symptoms: 61.5% with feces formed, 53.8% without abdominal pain, 84.6% without steatorrhea; Adequacy in macronutrient consumption: 51.3% adequate consumption of carbohydrates and lipids, and 64.1% excessive consumption of proteins; Positive correlations: enzyme dose correlates with pain (p = 0.004) and BMI (p = 0.009); that is, patients who report more pain and who weigh more are those who receive the highest doses of pancreatic enzymes; Negative correlations: functional capacity and nutritional assessment parameters such as BMI (p = 0.004), and body fat percentage (p = 0.028), as well as clinical parameters such as enzyme dose (p = 0.022) and number of bowel movements per day p=0.024); Associations: the dietary lipid consumption inadequacy is associated with important gastrointestinal symptoms such as soft stool consistency (p=0.005) and flatulence (p=0.012), and emphasizes the importance of nutritional guidance to patients on pancreatic enzyme replacement therapy. CONCLUSION: Most patients presented good results of biochemical tests, quality of life, macronutrient consumption, nutritional status and gastrointestinal symptoms. Significant correlations and associations have been observed that evidence that nutritional status, food intake and enzyme dose interferes with gastrointestinal symptoms and self-perceived quality of life of patients. Therefore, the current protocol is valid, but should be associated with individualized nutritional guidance

No contexto da gerência de memória em sistemas operacionais, vários grupos de pesquisa desenvolvem trabalhos na área de algoritmos para gerência de memória virtual e alguns algoritmos para substituição de páginas têm sido propostos na literatura recente. No entanto, essas propostas não chegaram a um algoritmo que resolva satisfatoriamente o problema de desempenho na gerência de memória. Ainda não existe um consenso entre os pesquisadores de como essa questão deve ser tratada de maneira eficiente, e as propostas de algoritmos desenvolvidas possuem grande sobrecarga devido à sua complexidade. O objetivo deste trabalho é propor uma forma eficiente de gerenciar a memória com a composição de técnicas de busca, posicionamento e substituição de páginas. A hipótese aqui adotada é que para tratar o problema da gerência da memória é melhor consumir recursos computacionais determinando quais páginas deveriam estar na memória em um determinado instante de tempo do que gastar recursos determinando qual página será retirada da memória. A tese apresenta uma reanálise dos principais trabalhos que têm como objetivo o desempenho da gerência de memória, tornando possível retirar conclusões e ideias sobre quais fatores influenciam de maneira positiva com relação ao desempenho do sistema. A partir deste estudo, é determinado o conceito de qualidade do conteúdo da memória e criada uma métrica para medi-la. Aplicando tal conceito, formula-se um método sistêmico de construção de algoritmos de gerência de memória. Realiza-se uma aplicação desse método, criando-se então, os algoritmos RR+ng e RRlock+ng. A métrica é aplicada em simulações na fase final do método, mostrando-se adequada para realizar as análises. Os resultados obtidos mostram que a hipótese tratar o problema da gerência da memória, consumindo recursos computacionais determinando quais páginas devem estar na memória ao invés de quais devem deixá-la mostrou-se válida e parece promissora. / When it comes to memory management in operating systems, many research groups have been developing works in the memory management algorithms area and some page replacement algorithms have been proposed in the recent literature. Such proposals were not successful in developing algorithms that worked well as far as the performance in memory management is concerned. There is no consensus among the researches about how this problem can be treated efficiently, and the algorithms proposed have high overhead because of their complexity. The objective of this work is to propose an efficient memory management with the composition of page fetch, placement and replacement techniques. This thesis hypothesis is that to treat the memory management problem it is better to consume computational resources determining which pages must be in the memory in a given time than to waste resources defining which pages would be evicted from the memory. This work presents a reanalysis of the main works whose objective is memory management performance, making it possible to draw different conclusions and ideas about what factors may have a positive influence with respect to system performance. This study develops both the concept of quality of memory contents and a metric to measure it. Besides, a systemic method to create memory management algorithms is devised, applying the concept just created. Then, the method is followed, creating the RR+ng and RRlock+ng algorithms. In the final phase of the method, the metric is applied in simulations, proving to be adequate to perform the analysis. The results show that the idea of treating the memory management problem, consuming computational resources to determine which pages must be in the memory instead of which ones must leave it, hold true and seems to be promising.

INTRODUÇÃO: A artroplastia total do quadril é um dos procedimentos mais frequentes na ortopedia. O risco de infecção varia de 1 a 5%, e acarreta grande impacto negativo na qualidade de vida do paciente, além de envolver custos expressivos. O diagnóstico e tratamento precoce da infecção permite um tratamento mais rápido e efetivo, o que pode melhorar o resultado clínico final. Sabe-se que germes patogênicos podem contaminar o campo cirúrgico durante a cirurgia, apesar de rigorosa técnica asséptica, mas existe debate na literatura sobre a existência de benefício em identificar tais germes já na artroplastia primária em pacientes não infectados. Embora a coleta de múltiplas amostras para cultura seja prática bem estabelecida em procedimentos de revisão, permanece controversa a coleta de culturas em artroplastias primárias. Diversas bactérias podem contaminar o campo operatório durante a cirurgia, mas somente seriam capazes de causar infecção aquelas que contaminarem os planos anatômicos mais profundos. O objetivo deste estudo foi investigar se há valor prognóstico na realização de cultura de amostras profundas de tecido ósseo e de partes moles durante a realização da artroplastia total primária do quadril, buscando correlação entre a positividade das culturas e de infecção periprotética subsequente. MÉTODOS: Estudo retrospectivo, utilizando informações obtidas do prontuário médico e do sistema informatizado de consulta de exames laboratoriais. Foram colhidas amostras profundas (osso femoral, acetabular e cápsula) de 426 casos consecutivos de artroplastia total primária eletiva do quadril. Os pacientes foram seguidos por no mínimo três anos e foram identificados os pacientes que evoluíram com infecção. O perfil microbiológico das culturas nas cirurgias primárias foi comparado com aquele dos pacientes infectados. Adicionalmente, os prontuários foram revisados para a identificação de fatores de risco associados a maior risco de infecção periprotética. RESULTADOS: 54 cirurgias (12,6%) apresentaram culturas positivas. 16 casos (3,8%) evoluíram com infecção, dos quais cinco haviam apresentado cultura positiva na cirurgia primária. Os germes isolados nos pacientes infectados não coincidiram com os identificados na cirurgia índice. A taxa de infecção foi de 9,3% nos pacientes com cultura positiva e 3% naqueles com cultura negativa (p < 0,05), com um \"odds ratio\" de 3,34 (IC95% 1,09-10,24). Pacientes submetidos a alguma cirurgia prévia no quadril apresentaram taxa de infecção de 8,5%, sendo que tal percentual foi de 2,9% nos pacientes sem cirurgia prévia (p < 0,05). O único fator de risco associado a uma maior positividade de culturas foi o tabagismo (10,5% vs 23,6%, p < 0,05). CONCLUSÃO: Dentre os pacientes submetidos à artroplastia total primária do quadril, aqueles com cultura positiva apresentaram maior risco de desenvolvimento de infecção periprotética (IPP). Pacientes submetidos a algum procedimento cirúrgico prévio no mesmo quadril apresentaram maior risco de IPP / INTRODUCTION: The total hip arthroplasty is one of the most frequent procedures in orthopedics. The risk of infection usually varies from 1% to 5% and has a great negative impact on patients\' quality of life, while also involving significant costs. The diagnosis and early treatment of infection allows a faster and more effective treatment, which can improve the final clinical result. It is known that pathogenic germs can contaminate the surgical theater, despite strict aseptic technique, but there is debate in the literature regarding the benefit of identifying such germs during the primary arthroplasty in non-infected patients. Although the obtainment of multiple samples for culture is a well-established practice in revision procedures, the obtainment of cultures in primary arthroplasties remains controversial. Several bacteria can contaminate the operative field during surgery, but only those that contaminate the deeper anatomical layers should be capable of causing infection. The aim of this study was to investigate if there is prognostic value in the culture of deep samples of bone and soft tissues during primary total hip arthroplasty, seeking a correlation between the positivity of the cultures and subsequent periprosthetic infection. METHODS: This was a retrospective study, using information obtained from medical records and a computerized system for consultation of laboratory tests. Deep samples (femoral bone, acetabular bone and capsule) were collected from 426 consecutive cases of elective primary total hip arthroplasty. Patients were followed up for at least three years and patients who had developed infection were identified. The microbiological profile of cultures in the primary surgeries was compared to that of the infected patients. In addition, the medical records were reviewed for the identification of risk factors associated with a higher risk of periprosthetic infection. RESULTS: 54 surgeries (12.6%) presented positive cultures. 16 cases (3.8%) developed infection, of which five had presented a positive culture in the primary surgery. Isolated germs in infected patients did not coincide with those identified in the index surgery. The infection rate was 9.3% in patients with positive culture and 3% in those with negative culture (p < 0.05), with an odds ratio of 3.34 (95% CI 1.09-10.24). Patients who had a previous hip surgery had an infection rate of 8.5%, and this percentage was 2.9% in patients with no previous surgery (p < 0.05). The only risk factor associated with a higher risk of culture positivity was smoking (10.5% vs. 23.6%, p < 0.05). CONCLUSION: Among patients undergoing primary total hip arthroplasty, those with a positive culture had a higher risk of developing periprosthetic infection (PPI). Patients who had undergone previous surgical procedures in the same hip also presented a higher risk of PPI

Bakgrund:Dialysbehandling är en livslång behandling och kräver att patienten följer upp behandlingsrytmen för att kunna uppnå högsta möjliga livskvalitet. Olika livsförändringar uppstår i samband med uppkomsten av njurinsufficiens och påbörjad dialysbehandling. Livet med dialys innebär ofta ett helt nytt liv för patienterna. Syfte: Att beskriva upplevelser av dialysbehandling hos vuxna patienter med njurinsufficiens. Metod:En litteraturöversikt har använts som metod för att besvara arbetets syfte. Tretton vetenskapliga artiklar har analyserats med hjälp av fem olika steg framtagna av Fribergs analysmetod.  Huvudresultat:patienterna upplevde brist på information, behov av egen kontroll, förlust av aktiviteter och sociala relationer. Ibland upplevde patienterna behandlingen som påfrestande och hade svårt att anpassa livet efter det. Rädsla upplevdes också av de flesta patienterna, men däremot kunde säkerhet och trygghet upplevas när patienterna fick sin behandling av vårdpersonal som hade tillräckligt med kunskap och erfarenhet och när de hade familjen och vänner runt om sig. Slutsats:Patienterna hade både positiva och negativa upplevelser i samband med dialysbehandlingen. Vårdpersonalen och familjen spelade en viktig roll i patienterna liv och deras existens gjorde en inverkan i hur patienterna upplevde sin dialysbehandling. / Background:Dialysis treatment is a lifelong treatment and requires the patient to follow up on the treatment rhythm in order to achieve the highest possible quality of life. Different life changes occur in connection with the onset of renal insufficiency and initiated dialysis treatment. Life with dialysis often means a completely new life for patients. Aim:To describe the experiences of dialysis treatment in adult patients with renal insufficiency. Method:A literature review has been used as method for answering the purpose of this work. Thirteen scientific articles have been analyzed using five different steps developed by Friberg’s analysis method. Results:Patients experienced a lack of information, a need of own control, loss of activities and social relations. Sometimes patients experienced the treatment as stressful and had difficulty adjusting life after that. Fear was also experienced by most patients, but on the other hand, safety and security could be experienced when patients received their treatment by healthcare professionals who had enough knowledge and experience and also when they had family and friends around them.Conclusion: The patients had both positive and negative experiences in connection to the dialysis treatment. The healthcare staff and the family had an important role in the patients' lives and their existence made an impact on how the patients experienced their dialysis treatment.