114 research outputs found

    A new competitive implementation of the electromagnetism-like algorithm for global optimization

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    The Electromagnetism-like (EM) algorithm is a population- based stochastic global optimization algorithm that uses an attraction- repulsion mechanism to move sample points towards the optimal. In this paper, an implementation of the EM algorithm in the Matlab en- vironment as a useful function for practitioners and for those who want to experiment a new global optimization solver is proposed. A set of benchmark problems are solved in order to evaluate the performance of the implemented method when compared with other stochastic methods available in the Matlab environment. The results con rm that our imple- mentation is a competitive alternative both in term of numerical results and performance. Finally, a case study based on a parameter estimation problem of a biology system shows that the EM implementation could be applied with promising results in the control optimization area.Acknowledgments This work has been supported by FCT (Funda¸c˜ao para a Ciˆencia e Tecnologia, Portugal) in the scope of the project PEst-UID/CEC/00319/2013

    Cancro do colo do útero: que rastreio?

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    O cancro do colo do útero é um dos cancros evitáveis mais frequente nas mulheres, Ferlay (2004) e Parkin(2005). O padrão epidemiológico da doença, caracterizado por um período longo entre a detecção das primeiras lesões e a instalação da doença, favorece a sua inclusão em programas de rastreio organizado, por serem custo-eficientes e terem ganhos de saúde associados, ver Anttila (2004), Castellsague (2006) e Koutsky (1998). O presente estudo teve como objectivo auxiliar os elementos da Comissão de Rastreio do Cancro do Colo do Útero na Região Norte na tomada de decisões relativas aos aspectos mais controversos dos rastreios ao cancro do colo do útero: limite de idade das mulheres rastreadas, intervalo entre exames e método utilizado. Assim, construiu-se um modelo matemático, com o intuito de simular os impactos económicos e de saúde, das combinações das várias alternativas de rastreio. Por fim, foi feita uma análise custo-benefício das soluções encontradas e determinou-se a solução, i.e. a opção de rastreio, mais vantajosa.Cervical cancer is one of the most frequent avoidable cancers in women, Ferlay (2004) and Parkin(2005). The natural history of the disease, characterized for a long period between the detection of the rst injuries and invasive cancer, favours its inclusion in organized screening programs, since they are cost-e ective and have clear advantages for the health of the population, see Anttila (2004), Castellsague (2006) and Koutsky (1998). The aim of this study is to construct a mathematical model that can help the elements of the Commission delegated for planning the screening program, to decide about the most controversial aspects: target population, interval between examinations and method to be used. The mathematical model allows to simulate the economical and health impact of all the possible solutions. Finally, a cost-bene t analysis of the combined screening alternatives was done to determine the solution, i.e, the more advantageous screening program

    Higher number of Helicobacter pylori CagA EPIYA C phosphorylation sites increases the risk of gastric cancer, but not duodenal ulcer

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    <p>Abstract</p> <p>Background</p> <p><it>Helicobacter pylori </it>infection is one of the most common infections worldwide and is associated with gastric cancer and peptic ulcer. Bacterial virulence factors such as CagA have been shown to increase the risk of both diseases. Studies have suggested a causal role for CagA EPIYA polymorphisms in gastric carcinogenesis, and it has been shown to be geographically diverse. We studied associations between <it>H. pylori </it>CagA EPIYA patterns and gastric cancer and duodenal ulcer, in an ethnically admixed Western population from Brazil. CagA EPIYA was determined by PCR and confirmed by sequencing. A total of 436 patients were included, being 188 with gastric cancer, 112 with duodenal ulcer and 136 with gastritis.</p> <p>Results</p> <p>The number of EPIYA C segments was significantly associated with the increased risk of gastric carcinoma (OR = 3.08, 95% CI = 1.74 to 5.45, p < 10<sup>-3</sup>) even after adjustment for age and gender. Higher number of EPIYA C segments was also associated with gastric atrophy (p = 0.04) and intestinal metaplasia (p = 0.007). Furthermore, patients infected by <it>cag</it>A strains possessing more than one EPIYA C segment showed decreased serum levels of pepsinogen I in comparison with those infected by strains containing one or less EPIYA C repeat. Otherwise, the number of EPIYA C segments did not associate with duodenal ulcer.</p> <p>Conclusions</p> <p>Our results demonstrate that infection with <it>H. pylori </it>strains harbouring more than one CagA EPIYA C motif was clearly associated with gastric cancer, but not with duodenal ulcer.</p> <p>Higher number of EPIYA C segments was also associated with gastric precancerous lesions as demonstrated by histological gastric atrophic and metaplastic changes and decreased serum levels of pepsinogen I.</p

    Cryptorchidism in Children with Zika-Related Microcephaly.

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    The genitourinary tract was recently identified as a potential site of complications related to the congenital Zika syndrome (CZS). We provide the first report of a series of cryptorchidism cases in 3-year-old children with Zika-related microcephaly who underwent consultations between October 2018 and April 2019 as part of the follow-up of the children cohort of the Microcephaly Epidemic Research Group, Pernambuco, Brazil. Of the 22 males examined, eight (36.4%) presented with cryptorchidism. Among 14 undescended testis cases, 11 (78.6%) could be palpated in the inguinal region. Seven of the eight children had severe microcephaly. Conventional risk factors for cryptorchidism were relatively infrequent in these children. We hypothesize that cryptorchidism is an additional manifestation of CZS present in children with severe microcephaly. As in our cases, for most of the children, the testes were located in the inguinal region, and the possible mechanisms for cryptorchidism were gubernaculum disturbance or cremasteric abnormality

    ChEVAR technique for emergent aneurysm repair - a retrospective case series

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    INTRODUCTION: Chimney EVAR (ChEVAR) for the treatment of complex abdominal aortic aneurysm (AAA) has been largely relegated for when fenestrated endografts are unavailable, especially due to durability concerns. However, the off-the-shelf nature of ChEVAR makes it a good option for emergent AAA repair. We report our institutional experience in ChEVAR in an urgent setting. METHODS: ChEVAR procedures were collected from 2019 to 2023 in a tertiary hospital, and a retrospective analysis was performed. This includes gathered information from electronic medical records, surgical reports and the picture archiving system. Descriptive statistics were applied. The main endpoints were technical success, 30-day and 1-year survival. RESULTS: Five patients were submitted to urgent aneurysm repair using the chEVAR technique. Average age was 73,4 years and all patients were male. Arterial hypertension was present in 100% patients and all patients were ASA 4. Indications for surgery were post EVAR type 1a endoleak with associated rupture or abdominal pain in two patients; symptomatic/contained rupture of pararenal AAA in two patients; and contained rupture of a thoracoabdominal aneurysm in one patient. A total of eight target vessels were catheterized: two patients required single-vessel chimney and the remainder two-vessel chimney. Target vessels were two superior mesenteric arteries and six renal arteries. Technical success rate was 100% and 30-day mortality was 0%. There were no major complications. Follow-up time is 20.2 months (4.7-38). Target vessel patency during the follow-up period was 87.5%. Three patients (60%) died due to non-aortic related pathologies, on average 18 months after surgery (4.7-38), with a 1-year survival of 80%. CONCLUSION: Our experience with ChEVAR for emergent AAA repair is satisfactory, with high technical success rates and low short-term mortality. Sac regression, low rates of target vessel occlusion and type 1a endoleaks reveal a favourable profile for aneurysm exclusion. ChEVAR is a viable option in emergent setting for patients unfit for open repair
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