961 resultados para 2-methyl-1,3-propanediamine


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Experimental studies on phase equilibria and liquidus in the multicomponent system PbO-ZnO-CaO-SiO2-FeO-Fe2O3 in air have been conducted over the temperature range between 1323 K (1050 degreesC) and 1623 K (1350 degreesC) to characterize the phase relations of the complex slag systems encountered in lead and zinc blast furnace sinters. The liquidus in two pseudoternary sections ZnO-Fe2O3-(PbO + CaO + SiO2) with the CaO/SiO2 weight ratio of 0.933 and PbO/(CaO + SiO2) weight ratios of 2.0 and 3.2 have been constructed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We present two integrable spin ladder models which possess a general free parameter besides the rung coupling J. The models are exactly solvable by means of the Bethe ansatz method and we present the Bethe ansatz equations. We analyze the elementary excitations of the models which reveal the existence of a gap for both models that depends on the free parameter. (C) 2003 American Institute of Physics.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The crystal structures of a pair of cis and trans isomers of the macrocyclic chloropentaamine title complex, as their tetrachlorozincate(II) salts, [CoCl(C11H27N5)][ZnCl4], are reported. The two distinct isomeric forms lead to significant variations in the Co-N bond lengths and, furthermore, hydrogen bonding between the complex ions is influenced by the folded (cis) or planar (trans) conformations of the coordinated ligand.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A disciplina teve como principais conte??dos: as principais dimens??es institucionais que comp??em o Sistema Pol??tico Brasileiro e seus impactos sobre o funcionamento da Democracia no Brasil. Modelos de democracia em perspectiva comparada. O sistema de governo e as rela????es entre executivo e legislativo. Representa????o pol??tica, partidos e elei????es. O federalismo e as rela????es intergovernamentais. O papel pol??tico das institui????es de justi??a. Reforma Pol??tica. Os condicionamentos decorrentes das caracter??sticas do Sistema Pol??tico Brasileiro no processo decis??rio sobre pol??ticas p??blicas

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Diagn??stico geral a respeito das institui????es pol??ticas brasileiras. Sistema eleitoral e seus impactos sobre o sistema partid??rio. Rela????es Executivo-Legislativo e a Organiza????o Congressual no Brasil. O federalismo e seus impactos sobre o processo decis??rio. Judici??rio e Pol??tica no Brasil

Relevância:

100.00% 100.00%

Publicador:

Resumo:

New K/Ar dating and geochemical analyses have been carried out on the WNW-ESE elongated oceanic island of S. Jorge to reconstruct the volcanic evolution of a linear ridge developed close to the Azores triple junction. We show that S. Jorge sub-aerial construction encompasses the last 1.3 Myr, a time interval far much longer than previously reported. The early development of the ridge involved a sub-aerial building phase exposed in the southeast end of the island and now constrained between 1.32 +/- 0.02 and 1.21 +/- 0.02 Ma. Basic lavas from this older stage are alkaline and enriched in incompatible elements, reflecting partial melting of an enriched mantle source. At least three differentiation cycles from alkaline basalts to mugearites are documented within this stage. The successive episodes of magma rising, storage and evolution suggest an intermittent reopening of the magma feeding system, possibly due to recurrent tensional or trans-tensional tectonic events. Present data show a gap in sub-aerial volcanism before a second main ongoing building phase starting at about 750 ka. Sub-aerial construction of the S. Jorge ridge migrated progressively towards the west, but involved several overlapping volcanic episodes constrained along the main WNW-ESE structural axis of the island. Malic magmas erupted during the second phase have been also generated by partial melting of an enriched mantle source. Trace element data suggest, however, variable and lower degrees of partial melting of a shallower mantle domain, which is interpreted as an increasing control of lithospheric deformation on the genesis and extraction of primitive melts during the last 750 kyr. The multi-stage development of the S. Jorge volcanic ridge over the last 1.3 Myr has most likely been greatly influenced by regional tectonics, controlled by deformation along the diffuse boundary between the Nubian and the Eurasian plates, and the increasing effect of sea-floor spreading at the Mid-Atlantic Ridge.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We present a palaeomagnetic study on 38 lava flows and 20 dykes encompassing the past 1.3 Myr on S. Jorge Island (Azores ArchipelagoNorth Atlantic Ocean). The sections sampled in the southeastern and central/western parts of the island record reversed and normal polarities, respectively. They indicate a mean palaeomagnetic pole (81.3 degrees N, 160.7 degrees E, K= 33 and A95= 3.4 degrees) with a latitude shallower than that expected from Geocentric Axial Dipole assumption, suggesting an effect of non-dipolar components of the Earth magnetic field. Virtual Geomagnetic Poles of eight flows and two dykes closely follow the contemporaneous records of the Cobb Mountain Subchron (ODP/DSDP programs) and constrain the age transition from reversed to normal polarity at ca. 1.207 +/- 0.017 Ma. Volcano flank instabilities, probably related to dyke emplacement along an NNWSSE direction, led to southwestward tilting of the lava pile towards the sea. Two spatially and temporally distinct dyke systems have been recognized on the island. The eastern is dominated by NNWSSE trending dykes emplaced before the end of the Matuyama Chron, whereas in the central/western parts the eruptive fissures oriented WNWESE controlled the westward growth of the S. Jorge Island during the Brunhes Chron. Both directions are consistent with the present-day regional stress conditions deduced from plate kinematics and tectonomorphology and suggest the emplacement of dykes along pre-existing fractures. The distinct timing and location of each dyke system likely results from a slight shift of the magmatic source.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mushroom strains contain complex nutritional biomolecules with a wide spectrum of therapeutic and prophylactic properties. Among these compounds, β-d-glucans play an important role in immuno-modulating and anti-tumor activities. The present work involves a novel colorimetric assay method for β-1,3-d-glucans with a triple helix tertiary structure by using Congo red. The specific interaction that occurs between Congo red and β-1,3-d-glucan was detected by bathochromic shift from 488 to 516 nm (> 20 nm) in UV–Vis spectrophotometer. A micro- and high throughput method based on a 96-well microtiter plate was devised which presents several advantages over the published methods since it requires only 1.51 μg of polysaccharides in samples, greater sensitivity, speed, assay of many samples and very cheap. β-d-Glucans of several mushrooms (i.e., Coriolus versicolor, Ganoderma lucidum, Pleurotus ostreatus, Ganoderma carnosum, Hericium erinaceus, Lentinula edodes, Inonotus obliquus, Auricularia auricular, Polyporus umbellatus, Cordyseps sinensis, Agaricus blazei, Poria cocos) were isolated by using a sequence of several extractions with cold and boiling water, acidic and alkaline conditions and quantified by this microtiter plate method. FTIR spectroscopy was used to study the structural features of β-1,3-d-glucans in these mushroom samples as well as the specific interaction of these polysaccharides with Congo red. The effect of NaOH on triple helix conformation of β-1,3-d-glucans was investigated in several mushroom species.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação para obtenção do grau de Mestre em Engenharia Civil

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A new biomimetic sensor for leucomalachite green host-guest interactions and potentiometric transduction is presented. The artificial host was imprinted in methacrylic acid or acrylamido-2-methyl-1-propanesulfonic acid-based polymers. Molecularly imprinted particles were dispersed in 2-nitrophenyloctyl ether and trapped in poly(vinyl chloride). The potentiometric sensors exhibited a near-Nernstian response in steady state evaluations, with slopes and detection limits ranging from 45.8 to 81.2 mV and 0.28 to 1.01 , respectively. They were independent from the pH of test solutions within 3 to 5. Good selectivity was observed towards drugs that may contaminate water near fish cultures, such as oxycycline, doxycycline, enrofloxacin, trimethoprim, creatinine, chloramphenicol, and dopamine. The sensors were successfully applied to field monitoring of leucomalachite green in river samples. The method offered the advantages of simplicity, accuracy, applicability to colored and turbid samples, and automation feasibility.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Os autores trataram 13 indivíduos com a doença de Chagas, 4 na fase aguda e 9 na fase crônica, forma indeterminada, com o CL 71.366 do Laboratório Lederle, usando diferentes esquemas terapêuticos nos dois grupos. Embora a droga fosse relativamente bem suportada pela maioria dos indivíduos, todos os chagásicos, após o tratamento, continuavam com parasitemia demonstrável pelos xenodiagnósticos, apesar do controle de cura não ter sido rigoroso. Concluem os autores pela ineficácia do medicamento no tratamento da doença de Chagas, nos esquemas utilizados.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Mestre em Bioorgânica

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A pneumonia por Pneumocystis jirovecii (PPc) é uma das principais causas de morte em doentes imunocomprometidos, revestindo-se assim de elevado interesse o diagnóstico precoce desta infecção, por forma a instaurar a terapêutica adequada. Actualmente, os meios laboratoriais de diagnóstico baseiam-se fundamentalmente na detecção directa deste microrganismo nas secreções pulmonares dos doentes, o que implica a realização de procedimentos invasivos. É nessa perspectiva que surge o doseamento do β-glucano no soro de doentes com presumível infecção, uma vez que, este composto é um dos principais componentes da parede dos quistos de P. jirovecii. Neste estudo procedeu-se ao doseamento do β-glucano em amostras de soro de 66 indivíduos e verificou-se que, nos 47 indivíduos que confirmaram o diagnóstico de PPc, a mediana de β-glucano obtida foi de 314,5 pg/mL, enquanto nos restantes 19 foi de 63,7 pg/mL. Estatisticamente obteve-se uma forte correlação entre níveis elevados de β-glucano no soro de doentes e a presença de infecção por P. jirovecii. Em relação ao diagnóstico clínico, os resultados obtidos demonstraram correlação entre um diagnóstico clinico sugestivo de PPc e níveis elevados de β-glucano no soro. Constatou-se ainda que, para a infecção por P. jirovecii o cut-off que apresentou melhores resultados para o teste Fungitell® situa-se nos 100 pg/mL, obtiveram-se resultados de sensibilidade de 89% e especificidade de 74%. Estudos preliminares apontaram para o facto de níveis elevados de β-glucano no soro corresponderem a níveis elevados de parasitémia e uma evolução clínica negativa da doença.