785 resultados para Lighter trivalent lanthanides


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A procura por alternativas ao atual paradigma energético, que se caracteriza por uma predominância indiscutível das fontes combustíveis fósseis, é o motivo primário desta investigação. A energia emitida pelo Sol que chega à Terra diariamente ultrapassa em várias ordens de grandeza a energia que a nossa sociedade atual necessita. O efeito chaminé é uma das formas de aproveitar essa energia. Este efeito tem origem no diferencial de temperaturas existente entre o interior e o exterior de uma chaminé, que provoca um gradiente nas massas volúmicas do fluido entre o interior e o exterior da chaminé, induzindo assim um fluxo de ar. Esta diferença de temperaturas radica na exposição da face exterior da chaminé à radiação solar. No sistema que nos propomos estudar, o ar entra na chaminé por pequenos orifícios situados na sua base, e, ao tomar contacto com as paredes internas da chaminé, aquece desde a temperatura ambiente, Ta, até à temperatura interna, Ti . Este aumento de temperatura torna o ar dentro da chaminé mais “leve” em comparação com o ar mais frio do exterior levando-o a ascender ao longo do interior da chaminé. Este escoamento contém energia cinética que pode, por exemplo, ser transformada em energia elétrica por intermédio de turbinas. A eficiência de conversão da energia será tanto maior quanto menor for a velocidade do ar a jusante da turbina. Esta tecnologia poderá ser instalada de forma descentralizada, como acontece com as atuais centrais concentradoras solares térmicas e fotovoltaicas localizadas na periferia de grandes cidades ou, alternativamente, poderá ser inserida no próprio tecido urbanístico. A investigação demonstra que as dimensões da chaminé, a irradiação e a temperatura do ar são os fatores com maior impacto na potência hidráulica gerada.

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Dissertação para obtenção do Grau de Doutor em Química Sustentável

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In the context of this dissertation several studies were developed resulting in submission and publication “Evaluation of mechanical soft-abrasive blasting and chemical cleaning methods on alkyd-paint graffiti made on calcareous stones” to Journal of Cultural Heritage. (http://dx.doi.org/10.101 /j.culher.2014.10.004)

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ABSTRACTINTRODUCTION:While no single factor is sufficient to guarantee the success of influenza vaccine programs, knowledge of the levels of immunity in local populations is critical. Here, we analyzed influenza immunity in a population from Southern Brazil, a region with weather conditions that are distinct from those in the rest of country, where influenza infections are endemic, and where greater than 50% of the population is vaccinated annually.METHODS:Peripheral blood mononuclear cells were isolated from 40 individuals. Of these, 20 had received the H1N1 vaccine, while the remaining 20 were unvaccinated against the disease. Cells were stimulated in vitro with the trivalent post-pandemic influenza vaccine or with conserved major histocompatibility complex I (MHC I) peptides derived from hemagglutinin and neuraminidase. Cell viability was then analyzed by [3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide)]-based colorimetric assay (MTT), and culture supernatants were assayed for helper T type 1 (Th1) and Th2-specific cytokine levels.RESULTS:Peripheral blood lymphocytes from vaccinated, but not unvaccinated, individuals exhibited significant proliferation in vitro in the presence of a cognate influenza antigen. After culturing with vaccine antigens, cells from vaccinated individuals produced similar levels of interleukin (IL)-10 and interferon (IFN)-γ, while those from unvaccinated individuals produced higher levels of IFN-γ than of IL-10.CONCLUSIONS:Our data indicate that peripheral blood lymphocytes from vaccinated individuals are stimulated upon encountering a cognate antigen, but did not support the hypothesis that cross-reactive responses related to previous infections can ameliorate the immune response. Moreover, monitoring IL-10 production in vaccinated individuals could comprise a valuable tool for predicting disease evolution.

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Ventilator-dependent premature infants are often treated with dexamethasone. Several trials showed that steroids while improve pulmonary compliance and facilitate extubation, some treated infants may have adverse effects, such as alterations of growth curves. We conducted this retrospective study to evaluate the effects of steroids on mechanical ventilation, oxygen therapy, hospital length stay and mortality, in ventilator-dependent infants with bronchopulmonary dysplasia (BPD) (defined as the need of oxygen supplementation at 28 days of life). Twenty-six newborns with BPD were evaluated during 9 -- 42 days postpartum (mean = 31 days) and were divided into two groups: Group I - 14 newborns that did not receive dexamethasone, and Group II - 12 newborns that received dexamethasone at 14 --21 days of life. Dexamethasone was given at a dose of 0.25 mg per kilogram of body weight twice daily intravenously for 3 days, after which the dose was tapered. RESULTS: There were no statistically significant differences in the mean length of mechanical ventilation (Group I - 37 days, Group II - 35 days); oxygen supplementation (Group I - 16 days, Group II - 29 days); hospital stay (Group I - 72 days, Group II - 113 days); mortality (Group I - 35.7%, Group II - 41.6%). At birth, Group II was lighter (BW: Group I - 1154 grams ± 302, Group II - 791 grams ± 165; p < 0.05) and smaller (height: Group I - 37.22 cm ± 3.3, Group II - 33.5 ± 2.4; p< 0.05) than Group I. At 40 weeks, there were no statistically significant differences between groups in relation to anthropometric measurements. CONCLUSIONS: The use of corticosteroids in bronchopulmonary dysplasic infants may influence the somatic growth during its use. However, after its suspension, a recovery seems to occur, suggesting that its influence could be transitory.

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The subject of study of this Thesis aims to highlight and recognize as an object of reflection the undoubted relationship between the Internet and the Justice System, based on the issue of digital evidence. The simultaneously crossing of the juridical-legal implications and the more technical computer issues is the actual trigger for the discussion of the issues established. The Convention on Cybercrime of the Council of Europe of 23rd November 2001 and the Council Framework Decision n.° 2005/222/JHA of 24th February 2005 were avant-garde in terms of the international work about the crimes in the digital environment. In addition they enabled the harmonization of national legislations on the matter and, consequently, a greater flexibility in international judicial cooperation. Portugal, in compliance with these international studies, ratified, implemented and approved Law n. º 109/2009 of 15th September concerning the Cybercrime Act, establishing a more specific investigation and collection of evidence in electronic support when it comes to combating this type of crime, as it reinforced the Substantive Criminal Law and Procedural Nature. Nevertheless, the constant debates about the New Technologies of Information and Communication have not neglected the positive role of these tools for the user. However, they express a particular concern for their counterproductive effects; a special caution prevails on the part of the judge in assessing the digital evidence, especially circumstantial evidence, due to the its fragility. Indisputably, the practice of crimes through the computer universe, given its inexorable technical complexity, entails many difficulties for the forensic investigation, since the proofs hold temporary, changeable, volatile, and dispersed features. In this pillar, after the consummation of iter criminis, the Fundamental Rights of the suspects may be debated in the course of the investigation and the construction of iter probatorium. The intent of this Thesis is to contribute in a reflective way on the issues presented in order to achieve a bigger technical and legal awareness regarding the collection of digital proof, looking for a much lighter approach to its suitability in terms of evidentiary value.

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Tese de Doutoramento Ciência e Engenharia de Polímeros e Compósitos.

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Dissertação de mestrado em Engenharia Mecânica

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Among the most important factors influencing beer quality is the presence of well-adjusted amounts of higher alcohols and esters; as well as the successful reduction of undesirable by-products such as diacetyl. While higher alcohols and esters contribute rather positively to the beer aroma, diacetyl is mostly unwelcome for beer types with lighter taste. Thus, the complex metabolic pathways in yeast responsible for the synthesis of both pleasant and unpleasant by-products of fermentation were given special attention in this last chapter.

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OBJECTIVE: To compare the heart weight and the heart weight/body weight coefficient of adults with and without chronic malnutrition. METHODS: In an initial case series of 210 autopsies performed in adults, we recorded body and heart weights and calculated the heart weight/body weight coefficients (HW/BW x 100). The exclusion criteria were as follows: positive serology for Chagas' disease, edema, obesity, heart diseases, hepatopathies, nephropathies, and systemic arterial hypertension. Malnutrition was characterized as a body mass index <18.5kg/m². Differences with p<0.05 were considered significant. RESULTS: Individuals in the malnourished (n=15) and control (n=21) groups were statistically different, respectively, in regard to body mass index (15.9±1.7 versus 21.3±2.5kg/m²), heart weight (267.3±59.8 versus 329.1±50.4g), and the HW/BW coefficient (0.64±0.12 versus 0.57±0.09%). A positive and significant correlation was observed between heart weight and body mass index (r=0.52), and between heart weight and body weight (r=0.65). CONCLUSION: Malnourished individuals have lighter hearts and a greater HW/BW coefficient than non-malnourished individuals do. These findings indicate a possible preservation of the myocardium in relation to the intensity of weight loss associated with the probable relative increase in cardiac connective tissue and heart blood vessels.

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The reproductive capacity of females of Apanteles galleriae (Wilkinson, 1932) was evaluated in fifth instar caterpillars of Galleria mellonella (Linnaeus, 1758) and Achroia grisella (Fabricius, 1754) fed on standard diet and diets enriched with protein. The reproductive capacity of parasitoid females on fifth instar caterpillars of G. mellonella and A. grisella with variable weight was also evaluated. The host weight interfered in the sex ratio of the obtained parasitoids. In heavier caterpillars, the investment in female descendants was greater than in males, and in lighter caterpillars the inverse occurred.

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Based on the available data from the Hospital responsible for the care of paralitic poliomyelitis cases in Rio de Janeiro City (Guanabara State) and adjacent areas, and the laboratory studies carried out on these patients, the authors analize epidemiological aspects of poliomyelitis in a period of ten years (1961 to 1970). Paralitic poliomyelitis remains a public health problem, with a typical incidence in the less than 4 year age group. All three poliovirus types have been prevalent for at least one period of time during the last ten years. Trivalent oral vaccine has been used since 1961 but the vaccination levels achieved were not enough to a permanent control of the disease. A definite seasonal distribution of cases could not be observed with the available data. Active mass campaign vaccinations with previous motivation of all segments of the population, specially the low-income groups instead of passive waiting of children in Vaccination Centers seems to be the best aproach to control poliomyelitis in this area.

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Toddia França, 1912 under the light microscope occurs as inclusion corpuscles in the cytoplasm of erythrocytes of cold-blooded vertebrates sometimes accompanied by crystalloid bodies. Its position among the protozoans or the viruses has been discussed by some authors, but remained unclear. To elucidate this problem we studied Toddia from a Brazilian frog (Leptodactylus ocellatus) by electron microscopy. In the cytoplasm of the infected cells we found no protozoan, but rather virus-like particles often hexagonal in outline, averaging 195 nm excluding their two involving membranes, and presenting a central area of variable electron density. Particles at different stages of development were generally found around or on area lighter density than the cytoplasm. which resembled a virus synthesis site. At high magnification, the nuclear or cytoplasmic crystals allied to Toddia resembled the crystalline lattice of the inclusion bodies associated with the polyhedrosis viruses and poxviruses from insects, of the capsules of granulosis viruses and of other protein crystals in ultrathin sections. Cytochemical tests in Toddia corpuscles displayed exclusively the presence of deoxyribonucleic acid. These findings indicate that Toddia is not a protozoan and demonstrate that it is in all probability a viral inclusion corpuscle. Taking into account the nucleic acid type found in its structure (DNA) and the hexagonal shape usually shown in ultrathin sections by its component particles, which have a cytoplasmic site of synthesis and assembly, we tentatively relate Toddia with the so-called "Icosahedral Cytoplasmic Deoxyriboviruses". We believe that the present paper gives the first report of virus-like particles in L. ocellatus.

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Background: Although smokers tend to have a lower body-mass index (BMI) than non-smokers, smoking may affect body fat (BF) distribution. Some studies have assessed the association between smoking, BMI and waist circumference (WC), but, to our knowledge, no population-based studies assessed the relation between smoking and BF composition. We assessed the association between amount of cigarette smoking, BMI, WC and BF composition. Method: Data was analysed from a cross-sectional population-based study including 6'187 Caucasians aged 32-76 and living in Switzerland. Height, weight and WC were measured. BF, expressed in percent of total body weight, was measured by electrical bioimpedance. Abdominal obesity was defined as a WC 0102 cm for men and 088 cm for women and normal WC as <94 cm for men and <80 cm for women. In men, excess BF was defined as %BF 028.1, 28.7, 30.6 and 32.6 for age groups 32-44, 45-54, 55-64 and 65-76, respectively; the corresponding values for women were 35.9, 36.5, 40.5 and 44.4. Cigarette smoking was assessed using a self-reported questionnaire. Results: 29.3% of men and 25.0% of women were smokers. Prevalence of obesity, abdominal obesity, and excess of BF was 16.9% and 26.6% and 14.2% in men and 15.0%, 33.0% and 27.5% in women, respectively. Smokers had lower age-adjusted mean WC and percent of BF compared to non-smokers. However, among smokers, mean age-adjusted WC and BF increased with the number of cigarettes smoked per day: among light (1-10 cig/day), moderate (11-20) and heavy smokers (>20), mean ± SE %BF was 22.4 ± 0.3, 23.1 ± 0.3 and 23.5 ± 0.4 for men, and 31.9 ± 0.3, 32.6 ± 0.3 and 32.9 ± 0.4 for women, respectively. Mean WC was 92.9 ± 0.6, 94.0 ± 0.5 and 96.0 ± 0.6 cm for men, and 80.2 ± 0.5, 81.3 ± 0.5 and 83.3 ± 0.7 for women, respectively. Compared with light smokers, the age-adjusted odds ratio (95% Confidence Interval) for excess of BF was 1.04 (0.58 to 1.85) for moderate smokers and 1.06 (0.57 to 1.99) for heavy smokers in men (p-trend = 0.9), and 1.35 (0.92 to 1.99) and 2.26 (1.38 to 3.72), respectively, in women (p-trend = 0.04). Odds ratio for abdominal obesity vs. normal WC was 1.32 (0.81 to 2.15) for moderate smokers and 1.95 (1.16 to 3.27) for heavy smokers in men (p-trend <0.01), and 1.15 (0.79 to 1.69) and 2.36 (1.41 to 3.93) in women (p-trend = 0.03). Conclusion: WC and BF were positively and dose-dependently associated with the number of cigarettes smoked per day in women, whereas only WC was dose dependently and significantly associated with the amount of cigarettes smoked per day in men. This suggests that heavy smokers, especially women, are more likely to have an excess of BF and to accumulate BF in the abdomen compared to lighter smokers.

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Current methods for the control of the cattle tick Boophils microplus and the agent of bovine babesiosis, Babesia bovis are unsatisfactory. Effective immunological control of both parasites would have great advantages. However, naturally acquired immunity to the tick is generally unable to prevent serious production losses. A vaccine against the tick, based on a novel form of immunization, is being developed. A protective antigen has been isolated from the tick, characterized and produced as an effective, recombinant protein. A vaccine incorporating this antigen is currently undergoing field trials. In the Australian situation, improved tick control will probably increase endemic instability with respect to B. bovis. Fortunately, a trivalent, recombinant B. bovis vaccine has also been developed. This too is now undergoing pre-registration field trials.