12,127 research outputs found
IMUNOTERAPIA COM VENENO DE HIMENÓPTEROS: A EXPERIÊNCIA DE UMA CONSULTA
Resumo: Na Europa a prevalência de alergia ao veneno de himenópteros estima-se em 20%. As reacções sistémicas graves são indicação para imunoterapia específica com veneno de himenópteros após confirmação de atopia. Esta é eficaz em 91-100% dos casos de alergia ao veneno de vespa e 77-80% dos casos de alergia ao veneno de abelha. Apresentamos quatro casos clínicos de doentes com reacções sistémicas ao veneno de himenópteros que efectuaram imunoterapia. Três crianças apresentavam alergia ao veneno de abelha e uma ao veneno de vespa. Tinham IgE específica para o veneno de himenópteros, classes IV a VI. A duração da imunoterapia variou entre quatro e sete anos, com diminuição da classe de IgE específica em todos os doentes no final do tratamento. Três crianças tiveram contacto com o alergénio, durante ou após terminarem a imunoterapia, e nenhuma delas desencadeou uma reacção sistémica. A duração da imunoterapia continua a ser controversa. A ausência de reacção após contacto com o alergénio é sugestiva de sucesso do tratamento
Determination of the Blend Level of Mixtures of Biodiesel with Mineral Diesel Fuel Using Near Infrared Spectroscopy
Terra preta nova.
Amazonian soils are almost universally thought of as extremely forbidding. However, it is now clear that complex societies with large, sedentary populations were present for over a millenium before European contact. Associated with these are tracts of anomalously fertile, dark soils termed terra preta. These soils are presently an important agricultural resource within Amazonia. They provide a model for developing long-term future sustainability of food production simple carbon based soil technologies in tropical environments, particularly among small holders
Caracterização química e física da camada superficial do solo em clareiras com diferentes idades de revegetação na Província Petrolífera de Urucu, Coari-AM.
Este estudo tem por objetivo a caracterização química e física da camada superficial do solo em clareiras com diferentes idades do início de processo de revegetação na Província Petrolífera de Urucu, Coari - AM
New control algorithm for single-phase series active power filter
This paper presents a single-phase Series Active Power Filter (Series APF) for mitigation of the load voltage harmonic content, while maintaining the voltage on the DC side regulated without the support of a voltage source. The proposed series active power filter control algorithm eliminates the additional voltage source to regulate the DC voltage, and with the adopted topology it is not used a coupling transformer to interface the series active power filter with the electrical power grid. The paper describes the control strategy which encapsulates the grid synchronization scheme, the compensation voltage calculation, the damping algorithm and the dead-time compensation. The topology and control strategy of the series active power filter have been evaluated in simulation software and simulations results are presented. Experimental results, obtained with a developed laboratorial prototype, validate the theoretical assumptions, and are within the harmonic spectrum limits imposed by the international recommendations of the IEEE-519 Standard
Causal Anomalies in Kaluza-Klein Gravity Theories
Causal anomalies in two Kaluza-Klein gravity theories are examined,
particularly as to whether these theories permit solutions in which the
causality principle is violated. It is found that similarly to general
relativity the field equations of the space-time-mass Kaluza-Klein (STM-KK)
gravity theory do not exclude violation of causality of G\"odel type, whereas
the induced matter Kaluza-Klein (IM-KK) gravity rules out noncausal
G\"odel-type models. The induced matter version of general relativity is shown
to be an efficient therapy for causal anomalies that occurs in a wide class of
noncausal geometries. Perfect fluid and dust G\"odel-type solutions of the
STM-KK field equations are studied. It is shown that every G\"odel-type perfect
fluid solution is isometric to the unique dust solution of the STM-KK field
equations. The question as to whether 5-D G\"odel-type non-causal geometries
induce any physically acceptable 4-D energy-momentum tensor is also addressed.Comment: 16 page. LaTex file. To appear in Int. J. Mod. Phys. A (1998
Hg-supported phospholipid monolayer as rapid screening device for low molecular weight narcotic compounds in water
This study positions the fabricated Pt/Hg-supported phospholipid sensor element in the context of more conventional biomembrane-based screening platforms. The technology has been used together with immobilised artificial membrane (IAM) chromatography and COSMOmic simulation methods to screen the interaction of a series of low molecular weight narcotic organic compounds in water with phosphatidylcholine (PC) membranes. For these chemicals it is shown that toxicity to aquatic species is related to compound hydrophobicity which is associated with compound accumulation in the phospholipid membrane as modelled by IAM chromatography measurements and COSMOmic simulations. In contrast, the Hg-supported dioleoyl phosphatidylcholine (DOPC) sensor element records membrane damage/modification which is indirectly related to general toxicity and directly related to compound structure. Electrochemical limit of detection (LoD) values depend on molecular structure and range from 20 μmolL−1 for substituted phenols to 23 mmolL−1 for aliphatics. Rapid cyclic voltammetry (RCV) “fingerprints” showed that the major structural classes of compounds: alkyl/chlorobenzenes, substituted phenols, quaternary ammonium compounds and neutral amines interacted distinctively with the DOPC on Hg and that these observations correlated with and supported those predicted by the COSMOmic simulations of the compound/DMPC association. In addition, the compatibility of the electrochemical and COSMOmic methods validates the electrochemical device as a meaningful high throughput technology to screen compounds in water and report on the mechanistic details of their interaction with phospholipid layers
Efeito do floroglucinol na reação morfogênica in vitro de segmentos internodais de Citrus sinensis (Linn.) Osbeck cv. Pêra.
Conduziu-se este trabalho em condicoes controladas de laboratorios, com o objetivo de avaliar os efeitos do floroglucinol, em diferentes niveis, sobre a reacao morfologica in vitro de segmentos internodais, casca e cilindro central de Citrus sinensis (Linn.) Osbeck cv. Pera. Utilizou-se, para multiplicacao, o meio basico de MS Semi-solido com complementos organicos em mg L-1: mio-inositol 100, sacarose 30.000, extrato de malte 500, BAP (6-benzilaminopurina) 0,3 e floroglucinol em niveis 0, 30, 60, 90 e 120 incubados no escuro, por quatro semanas, e mais quatro semanas, sob luz com fotoperiodo de 16 horas. Brotacoes adventicias obtidas do explante casca foram submetidas ao enraizamento em meio semi-solido MS com os complementos organicos em mg L-1: mio-inositol 55, sacarose 87,600, ANA (acido x-naftalenoacetico) 0,09. O delineamento experimental foi inteiramente casualizado com cinco repeticoes, considerando-se, em cada uma, a media de quatro tubos de ensaio. Nas avaliacoes morfogenicas, observou-se que nos explantes casca nao ocorreu influencia sobre o percentual de culturas calejadas e com gemas adventicias, bem como comprimento das brotacoes adventicias, o mesmo nao ocorrendo com as caracteristicas numero de brotacoes adventicias por explante e percentagem de brotacoes enraizadas, que apresentaram reducao e aumento linear, respectivamente, nos explantes do cilindro central, nao houve influencia sobre o percentual de culturas calejadas e com gemas adventicias
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