978 resultados para Reações alérgicas


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Pós-graduação em Química - IQ

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Cosmic radiation has been identi ed as one of the main hazard to crew, aircraft and sensitive equipments involved in long-term missions and even high-altitude commercial ights. Generally, shields are used in spatial units to avoid excessive exposure, by holding the incident radiation. Unfortunatelly, shielding in space is problematic, especially when high-energy cosmic particles are considered, due to the production of large number of secondary particles, mainly neutrons, protons and alpha particles, caused by spallation reactions and quasi-elastic processes of the corpuscular radiation with the shield. Good parameters for checking the secondary particle production at target material are diferential cross section and energy deposited in the shield. Addition experiments, some computer codes based on Monte Carlo method show themselves a suitable tool to calculate shield parameters, due to have evaluated nuclear data libraries implemented on the algorithm. In view of this, the aim of this work is determining the parameters evaluated in shielding materials, by using MCNPX code, who shows good agreement with experimental data from literature. Among the materials, Aluminium had lower emission and production of secondary particles

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Multicomponent Reactions are defined as reactions between three or more reagents in a single reaction step in the same reaction vial, forming a product that includes the majority of atoms and structural characteristics of the reagents. Thus these reactions save time and energy. One of the ways to improve the yield and reaction time of a multicomponent reaction is to use different catalysts, an example of catalyst that shows great potential and has been studied in recent years is the molecular iodine is known to be a Lewis acid with high catalytic power. The functionalized piperidines, also known as tetrahydropyridines, are alkaloids that have pharmacological potential, this is due to the piperidine ring present in many natural product structures with muscarinic activity, nicotine, analgesic, antipsychotic, anti-proliferative, among others. In this paper we describe studies about on the application of molecular iodine (I2) in the multicomponent reaction between aniline derivatives, benzaldehyde and β-ketoester (methyl acetoacetate) for the synthesis of functionalized piperidines and the synthesis of a corresponding piperidone by acid hydrolysis. Data analysis allowed us to demonstrate the efficacy of molecular iodine in the synthesis of functionalized piperidines, obtaining results with yields 44-87% and short reaction time of 8 to 24 hours, and the efficacy of acid hydrolysis of enamine in the structure of the tetrahydropyridine derivative in a yield of 81%

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The biocompatibility of two dentin adhesives (Scotchbond MultiPurpose- 3M and Optibond Multi-Use - Kerr) was evaluated in rats subcutaneous connective tissue implants. Polyethylene tubes filled with the adhesives were surgically implanted into the dorsal subcutaneous tissues of rats. The tubes were left implanted for periods of 14, 30, 60 and 84 days, following wich the animais were killed and the implants, together with the surrounding tissue, were excised. The specimens were then fixed in 10 per cent formalin, sectioned serially and stained with hematoxylin and eosin and then, examined by light microscopy. After 14 and 30 days the tubes were surrounded by a mild to moderate inflammatory infiltration. After 60 and 84 days microscopic examination revealed the formation of a connective tissue capsule around each tube. The microscopic examination of the biopsy specimens allowed to conclude that: a) both dentin adhesives are considered biologically acceptable when placed in contact with rats subcutaneous connective tissue; b) in the observation period of 30 days there were moderate tissue reaction to the Optibond Multi-Use -light cure- (Kerr); c) after 60 and 84 days the use of both dentine adhesives did not interfere in the healing of the surrounding connective tissue

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Pós-graduação em Física - IFT

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Enfermagem (mestrado profissional) - FMB

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Undergraduate students on the first year of Chemistry Courses are unfamiliar with the representation of acid-base reactions using the ionic equation H+ + OH- → H2O. A chemistry class was proposed about acid-base reactions using theory and experimental evaluation of neutralization heat to discuss the energy involved when water is formed from H+ and OH- ions. The experiment is suggested using different strong acids and strong base pairs. The presentation of the theme within a chemistry class for high school teachers increased the number of individuals that saw the acid-base reaction from this perspective.

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Determinou-se incidência de reações adversas a medicamentos (RAM) que levaram crianças a atendimento de emergência em um hospital universitário de São Paulo, SP. Foram analisadas, retrospectivamente, 23.286 fichas de atendimento (FA) em emergência pediátrica, a partir de código CID que indicasse possível RAM. Observaram-se 83 (0,36%) RAMs. A maioria ocorreu na faixa etária entre 1 a 5 anos com leve predominância no sexo masculino (51,8%). Os medicamentos mais implicados foram antibacterianos para uso sistêmico (53,0%), vacinas (9,6%) e analgésicos (7,2%). A maior parte das RAMs foram manifestações dérmicas (54,2%) ou gastrointestinais (22,9%). Duas RAMs foram consideradas graves (2,4%) e levaram a internação; enquanto 61,4% foram leves e 36,1% foram moderadas. A incidência foi inferior à literatura, provavelmente por ser estudo retrospectivo, utilizando-se o CID para seleção das FA. Observou-se que, no Brasil, as RAMs levam crianças a atendimento de emergência, com características semelhantes às de outros países. Intervenções são necessárias para melhorar o diagnóstico e a utilização de antimicrobianos, uma vez que foram os medicamentos mais implicados nas RAMs observadas. A pesquisa no setor de emergência hospitalar é importante para se conhecer as RAMs que ocorrem fora do contexto hospitalar, podendo contribuir para identificar aquelas de maior gravidade. A metodologia utilizada, apesar das limitações, requer poucos recursos humanos e materiais, sendo uma boa alternativa para um diagnóstico inicial, que deve ser sucedido por estudos mais elaborados e de maior sensibilidade para detectar essas reações e propor medidas dirigidas à sua prevenção.

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