Reverse Saturable Absorption
Mostrando 1-6 de 6 artigos, teses e dissertações.
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1. Reverse saturable absorption in 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphyrin with ruthenium outlying complexes
Modificações no sinal de absorção de estado excitado da 5,10,15,20-tetra(4-piridil)-21H,23H-porfirina, provocadas tanto pela substituição do íon central quanto pela adição de grupos periféricos, são investigadas empregando-se pulsos laser de 5 ns com 532 nm, juntamente com medidas de absorção linear e tempo de decaimento da fluorescência. A abs
Journal of the Brazilian Chemical Society. Publicado em: 2006-12
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2. "Estudo e desenvolvimento de limitadores ópticos" / Study and development of optical limiters
Neste trabalho, com objetivo de desenvolvermos dispositivos de limitação óptica, estudamos o processo de absorção de estado excitados em um grupo de tetrapiridil porfirinas com diferentes substituintes centrais (2H+, Zn2+, Ni2+, Cu2+). Para isso utilizamos a técnica de varredura Z com pulsos de femto e picossegundos bem como com trem de pulsos. Dest
Publicado em: 2005
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3. Optical limiting in porphyrin and metaloporphyrin complexes / Limitação óptica em complexos de porfirina e metaloporfirina
Optical limiters are devices with a high transmittance in the presence of low intensity light, and a considerable lower transmittance otherwise, been used as protectors against damage in optical sensors and human eyes. Aiming at searching for new materials and optical geometries efficient for optical limiting. We report on the development of an optical limit
Publicado em: 2001
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4. Jejunal and ileal absorption in patients with chronic renal disease. Effect of 1alpha-hydroxycholecalciferol.
Calcium absorption in 30-cm segments of small intestine was measured by constant perfusion of test solutions containing different concentrations of calcium gluconate. In both the jejunum and ileum, calcium absorption rates increased progressively as luminal calcium concentration was increased stepwise between 1 and 20 mM. Although calcium transport was not s
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5. Delta-aminolevulinic acid transport by intestinal and renal peptide transporters and its physiological and clinical implications.
Delta-aminolevulinic acid (ALA) is the precursor of porphyrin synthesis and has been recently used in vitro and in clinical studies as an endogenous photosensitizer for photodynamic therapy in the treatment of various tumors. For this purpose, ALA is given topically, systemically, or orally. When administered by the oral route, it shows excellent intestinal
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6. Non-ionic diffusion and carrier-mediated transport drive extracellullar pH regulation of mouse colonic crypts.
1. Extracellular pH (pHo) regulation within mouse colonic crypt lumens is stimulated by transepithelial gradients of short-chain fatty acids (SCFAs). Current work assesses underlying mechanisms contributing to pHo regulation. 2. Crypt luminal alkalinization was saturable by apical SCFA (substrate concentration activating half-maximal transport (KT) of isobut