262 resultados para SETÚBAL
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Tese de Doutoramento em Ciências da Educação - Especialidade em Filosofia da Educação
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Dissertação de mestrado em Engenharia Industrial (área de especialização em Qualidade, Segurança e Manutenção)
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Sabedores da realidade tecnológica que envolve as crianças, sentimos necessidade de conhecer aprofundadamente como é que as crianças aprendem, ou seja, como estruturam e desenvolvem o seu pensamento, nesta relação com as tecnologias e através da programação. A presente investigação revela-se inovadora, quer no contexto em que vai ser implementado, quer nos objetivos da própria investigação. Pretendemos consolidar conhecimento sobre as teorias de aprendizagem, através da introdução da programação de forma lúdica e criativa nas atividades no jardim de infância. Compreender como as crianças reagem na utilização das tecnologias e da programação revela-se importante para conhecer o seu comportamento, o seu estilo de aprendizagem e permitir aos profissionais de educação antecipar ou não esta integração, nos seus contextos educativos. Conhecer como todo este processo de aprendizagem é vivenciado pelas crianças irá permitir avaliar quais os benefícios e riscos da utilização das tecnologias e da aprendizagem da programação em idade pré-escolar.
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Tese de Doutoramento em Engenharia Industrial e de Sistemas
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This study was designed to analyse the clinical and epidemiological data from human parvovirus B19 cases in a six-year study of rash diseases conduct in an urban area in Brazil (Niterói city area, State of Rio de Janeiro). A total of 673 patients with acute rash diseases were seen at two primary health care units and at a general hospital. A clotted blood sample was collected from all subjects at the time of consultation. Forty-nine per cent (330 cases) of the patients were negative for dengue, rubella and measles IgM or for low avidity IgG to HHV-6. Of these 330, 105 (31.8%) were identified as IgM positive to parvovirus B19 by using an antibody capture EIA. During the study period, three distinct peaks of parvovirus infection were detected, suggesting that the disease appears to cycle in approximately 4-5 years. B19 infection was characterized by variable combinations of fever, flu-like symptoms, arthropathy, and gastrointestinal symptoms. Frequency of fever and arthropathy was substantially higher in adults, 75% [chi2 (1 D.F.) = 11.39, p = 0.0007] and 62.5% [chi2 (1 D.F.) = 29.89, p = 0.0000], respectively. "Slapped-cheek" appearance and reticular or lace-like rash were seen in only 30.1% of the children. No adult presented this typical rash. The lack of the typical rash pattern in a large proportion of parvovirus B19 and the similarity of clinical manifestations to other rash diseases, specially to rubella, highlight the difficulty of diagnosing B19 infection on clinical grounds alone.
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Erythrovirus B19 infection is usually benign but may have serious consequences in patients with hemolytic anemia (transient aplastic crisis), immunodeficiency (in whom persistent infection can lead to chronic bone marrow failure with anemia), or who are in the first or second trimester of gestation (spontaneous abortion, hydrops fetalis, and fetal death). Being non-enveloped, B19 resists most inactivation methods and can be transmitted by transfusion. B19 is difficult to cultivate and native virus is usually obtained from viremic blood. As specific antibodies may be absent, and there is no reliable immunological method for antigen detection, hybridization or polymerase chain reaction are needed for detecting viremia. A rapid method, gel hemagglutination (Diamed ID-Parvovirus B19 Antigen Test), can disclose highly viremic donations, whose elimination lessens the viral burden in pooled blood products and may even render them non-infectious. In order to obtain native antigen and to determine the frequency of viremic donors, we applied this test to blood donors in a period of high viral activity in our community. Positive or indeterminate results were re-tested by dot-blot hybridization. We tested 472 donors in 1998 and 831 ones in 1999. One viremic donor was found in 1999. We suggest that in periods of high community viral activity the gel hemagglutination test may be useful in avoiding highly viremic blood being added to plasma pools or directly transfused to patients under risk.
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This study was designed to determine the seroprevalence of herpes simplex virus type 2 (HSV-2) and to evaluate its association with age, sex as well as other demographic and behavioural factors in 150 human immunodeficiency virus (HIV) positive adults patients attending the general medical outpatient ward for routine care of Niterói, state of Rio de Janeiro, Brazil. Serum samples were screened for HSV-2 antibodies using an indirect ELISA. Eighty-three patients were men (mean age: 38.8) and 67 were women (mean age: 35.4). The estimated prevalence of HSV-2 was 52% (95% CI: 44-60%) and it was higher among men (53%) than among women (50.7%). Overall, the age of first sexual intercourse and past history of genital herpes were associated with HSV-2 seropositivity. Analysis by gender disclosed significant association of number of lifetime sex partners only among men. Although HSV-2 antibodies were frequent in the study group, genital herpes was reported by 21.8% of the HSV-2 positive subjects, indicating low awareness of the HSV-2 infection. These results may have public health importance for Brazil as the high rate of HSV-2 infection may act as a cofactor of HIV transmission.
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Erythrovirus B19 infects erythrocytic progenitors, transiently interrupting erythropoiesis. In AIDS patients it causes chronic anemia amenable to treatment. We looked for evidences of B19 infection in stored bone marrow material from patients with acquired immunodeficiency syndrome. Histological sections were made from stored paraffin blocks from 33 autopsies (39 blocks) and 35 biopsies (45 blocks, 30 patients) performed from 1988 to 2002. They were examined after hematoxylin-eosin (HE) staining, immunohistochemical (IHC), and in situ hybridization. HE revealed intra-nuclear inclusion bodies ("lantern cells") suggesting B19 infection in 19 sections corresponding to 19 of 63 patients examined with this test. Seven of 78 sections subjected to immunohistochemistry were positive, corresponding to 7 of 58 patients examined with this test. Fourteen sections corresponding to 13 of the 20 HE and/or IHC positive patients were subjected to in situ hybridization, with six positives results. Among the 13 patients subjected to the three techniques, only one gave unequivocal positive results in all and was considered a true positive. The frequency of B19 infection (1/63 patients) in the material examined can be deemed low.
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Parvovirus B19 (B-19) may cause chronic anaemia in immunosuppressed patients, including those infected with human immunodeficiency virus (HIV). We studied single serum samples from 261 consecutive HIV-infected patients using an enzyme immunoassay to detect IgG antibodies to B-19. The seroprevalence of B-19-IgG was 62.8%. The differences in seroprevalence across gender, age, educational categories, year of collection of the serum samples, clinical and antiretroviral therapy characteristics, CD4+ count, CD4+ and CD8+ percentage and CD4+/CD8+ ratios were neither substantial nor statistically significant. There was a non-significant, inverse association between B-19 seropositivity and plasma HIV load and haemoglobin level. Our results indicated that 37.1% of patients might be susceptible to B-19 infection and remained at risk for being infected, mainly during epidemic periods. As B-19 infection can be treated with immune globulin preparations, it may be included in the diagnostic approach toward chronic anaemia in HIV-infected patients.
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Dengue virus (DENV) and parvovirus B19 (B19V) infections are acute exanthematic febrile illnesses that are not easily differentiated on clinical grounds and affect the paediatric population. Patients with these acute exanthematic diseases were studied. Fever was more frequent in DENV than in B19V-infected patients. Arthritis/arthralgias with DENV infection were shown to be significantly more frequent in adults than in children. The circulating levels of interleukin (IL)-1 receptor antagonist (Ra), CXCL10/inducible protein-10 (IP-10), CCL4/macrophage inflammatory protein-1 beta and CCL2/monocyte chemotactic protein-1 (MCP-1) were determined by multiplex immunoassay in serum samples obtained from B19V (37) and DENV-infected (36) patients and from healthy individuals (7). Forward stepwise logistic regression analysis revealed that circulating CXCL10/IP-10 tends to be associated with DENV infection and that IL-1Ra was significantly associated with DENV infection. Similar analysis showed that circulating CCL2/MCP-1 tends to be associated with B19V infection. In dengue fever, increased circulating IL-1Ra may exert antipyretic actions in an effort to counteract the already increased concentrations of IL-1β, while CXCL10/IP-10 was confirmed as a strong pro-inflammatory marker. Recruitment of monocytes/macrophages and upregulation of the humoral immune response by CCL2/MCP-1 by B19V may be involved in the persistence of the infection. Children with B19V or DENV infections had levels of these cytokines similar to those of adult patients.
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Erythrovirus B19 (B19V) infection may cause red cell aplasia in patients infected with human immunodeficiency virus (HIV). The introduction of highly active antiretroviral therapy (HAART) has improved the immune function of these patients by modifying the course of B19V infection. The purpose of this study was to estimate the frequency of B19 seroconversion in a cohort of HIV-infected patients and evaluate the occurrence of B19V-related anaemia during the seroconversion period. Adult HIV-infected patients were studied at a public hospital in Niterói, state of Rio de Janeiro, Brazil. IgG and IgM antibodies against B19V were detected by an enzyme-linked immunosorbent assay and B19 viraemia was assayed by polymerase chain reaction. Medical records were reviewed for any clinical evaluation of anaemia. Seroconversion was detected in 31.8% of the 88 individuals who began the study as anti-B19V IgG-negative. No clinical manifestations of B19V infection were detected during the period of seroconversion. Patients who seroconverted were 5.40 times more likely to have anaemia than those who did not [odds ratio 5.40 (95% confidence interval: 1.33-22.93)]. Anaemia was detected in eight patients. All patients recovered from anaemia by either beginning or continuing HAART, without requiring blood transfusions. In the HAART era, B19V infection may only be associated with a course of disease characterised by less severe chronic anaemia. This milder course of B19V-associated disease is likely due to the increased immune function of HAART-treated patients.
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Immunocompromised patients may develop severe chronic anaemia when infected by human parvovirus B19 (B19V). However, this is not the case in human immunodeficiency virus (HIV)-infected patients with good adherence to highly active antiretroviral treatment (HAART). In this study, we investigated the clinical evolution of five HIV-infected patients receiving HAART who had B19V infections confirmed by serum polymerase chain reaction. Four of the patients were infected with genotype 1a strains and the remaining patient was infected with a genotype 3b strain. Anaemia was detected in three of the patients, but all patients recovered without requiring immunoglobulin and/or blood transfusions. In all cases, the attending physicians did not suspect the B19V infections. There was no apparent relationship between the infecting genotype and the clinical course. In the HAART era, B19V infections in HIV-positive patients may be limited, subtle or unapparent.
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Foram estudados dois clones de Eucalyptus com densidades básicas de 447 e 552 kg/m³. O processo kraft foi utilizado para a produção de celulose, tendo sido aplicadas diferentes cargas de álcali para se obterem polpas com número kappa 18 ± 0,5. As polpas foram branqueadas pela seqüência ODEopDD, a alvuras de 90 ± 1% ISO, e refinadas, sendo suas propriedades físico-mecânicas e ópticas analisadas. A madeira de baixa densidade mostrou-se mais recomendável para a produção de celulose, por ter apresentado maior rendimento depurado, viscosidade da polpa mais elevada, ter requerido menor carga de álcali no cozimento, ter proporcionado menor teor de sólidos no licor residual e menor consumo de reagentes químicos no branqueamento. As propriedades mecânicas e estruturais das polpas não foram afetadas significativamente pela densidade básica das madeiras.
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Este artículo pertenece a una sección de la revista dedicada a estudios de caso
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O presente trabalho apresenta o estudo palinológico e mineralógico da camada superficial do solo, de dois Distritos de Portugal (Coimbra e Setúbal), com vista à determinação do potencial forense da utilização de amostras de solo, no que respeita à identificação do tipo de comunidade vegetal e material mineralógico da qual a amostra teve origem, que poderá ser utilizado para ligar pessoas e objectos ao local do crime. Para cumprir estes objectivos, foram recolhidas e estudadas amostras da camada superficial de solo, em locais com o mesmo tipo de comunidade vegetal (floresta mista) e diferente tipo de comunidade vegetal (dunas, matagal). Para o estudo polínico foram recolhidas 5 amostras de solo por local, totalizando 30 amostras, para o estudo da mineralogia foram recolhidas 2 amostras de solo por local, totalizando 12 amostras. Nas análises palinológicas das amostras identificaram-se 56 taxa sendo 5 de esporos, 2 de grãos de pólen de gimnospérmicas e 49 de grãos de pólen de angiospérmicas. Sempre que possível recorreu-se à caracterização das formas ao nível da espécie, contudo na maior parte dos casos a sua identificação foi feita ao nível do género. No que respeita ao estudo geológico foi realizada a análise granulométrica através da crivagem e por difracção a laser, originando como resultados a percentagem de minerais pesados contidos em cada amostra e a percentagem de minerais de fracção menor (argilas e siltes) e de fracção maior (areias, areão e seixo). A análise mineralógica foi efectuada através do estudo dos minerais por difracção de raios x em argilas, em lâminas glicoladas e pela fracção densa, resultando em valores quantitativos de minerais de quartzo, filossilicatos e feldspatos, em valores quantitativos e semi-quantitativos de minerais de ilite, moscovite, esmectite, clorite, interstratificados e caulinite e, por último, através do estudo da fracção densa, identificaram-se ao microscópio petrográfico, para cada amostra, os minerais pesados transparentes, num total de 12 tipos (alteritos, andaluzite, anfíbola, biotite, distena, epídoto, estaurolite, granada, moscovite, silimanite, turmalina e zircão). Por fim, contabilizaram-se os minerais opacos presentes em cada amostra.Os resultados obtidos sugerem que estes dois Distritos são extremamente díspares em termos palinológicos e mineralógicos, o que vem apoiar a ideia que numa cena de crime, o estudo do solo tem uma importância crucial, salientando assim o seu valor probatório e o seu potencial forense, sendo uma extraordinária ferramenta da investigação criminal, aliando pessoas aos locais do crime e/ou pessoas com pessoas, possibilitando assim, uma maior fiabilidade na caracterização do tipo de ambiente de onde uma amostra é originária.