56 resultados para Pigmento nanométrico


Relevância:

10.00% 10.00%

Publicador:

Resumo:

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

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Algae bloom is one of the major consequences of the eutrophication of aquatic systems, including algae capable of producing toxic substances. Among these are several species of cyanobacteria, also known as blue-green algae, that have the capacity to adapt themselves to changes in the water column. Thus, the horizontal distribution of cyanobacteria harmful algae blooms (CHABs) is essential, not only to the environment, but also for public health. The use of remote sensing techniques for mapping CHABs has been explored by means of bio-optical modeling of phycocyanin (PC), a unique inland waters cyanobacteria pigment. However, due to the small number of sensors with a spectral band of the PC absorption feature, it is difficult to develop semi-analytical models. This study evaluated the use of an empirical model to identify CHABs using TM and ETM+ sensors aboard Landsat 5 and 7 satellites. Five images were acquired for applying the model. Besides the images, data was also collected in the Guarapiranga Reservoir, in São Paulo Metropolitan Region, regarding the cyanobacteria cell count (cells/mL), which was used as an indicator of CHABs biomass. When model values were analyzed excluding calibration factors for temperate lakes, they showed a medium correlation (R²=0.81, p=0.036), while when the factors were included the model showed a high correlation (R²=0.96, p=0.003) to the cyanobacteria cell count. The empirical model analyzed proved useful as an important tool for policy makers, since it provided information regarding the horizontal distribution of CHABs which could not be acquired from traditional monitoring techniques.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Melanin is a very important pigment to human species, and besides defining skin, eyes and hair color, it is also involved in sun exposure protection. This pigment is classified into two subtypes: pheomelanin, which is responsible for lighter pigmentation and eumelanin, the dark pigment related. Due to this type of melanin variation it is possible to found different phenotypes of hair and skin color. The genetics MC1R variations are described as the most important for diversity in pigmentation, and this gene is directly related to the complex process of melanin synthesis. The use of these variations to phenotype prediction using genetic information has been used in Europe countries to infer physical features from biological samples, with the purpose of directing searches of criminal suspects and victims identification. The aim of this study was to analyze 8 major MC1R polymorphisms in a sample of Brazilian individuals. Analyzing 91 individuals, we observed with higher frequencies the polymorphisms rs1805005:G>T, rs2228479:G>A and rs885479:G>A, which are related to skin and hair colors, as previously showed in literature. These data suggest the possibility of predicting phenotype from genetic polymorphisms in Brazilian population. However it will be necessary to analyze a larger number of individuals to be able to confirm these associations and to perform a more detailed statistical analysis

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Violacein is a deeply violet pigment produced by Chromobacterium violaceum, an ubique tropical and subtropical bacterium. This molecule presents many biological activities including antimicrobial, antimycotic, antiviral, antiprotozoal and antitumoral. Important reports pointed to a considerable bactericide activity, which brings an extremely necessary quest. This work evaluated the resistance of some bacterias of interest veterinary. It was obtained significant inhibition activity against Staphylococcus aureus came from bovine mastitis. It was also obtained important synergic relations when violacein and penicillin or cloranphenicol are combined

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A curcumina, um pigmento natural extraído do rizoma da Curcuma longa L. é utilizada em alimentos, principalmente aqueles condimentados com curry e açafrão. Vários estudos demonstram seu efeito benéfico em diversas doenças, tais como: diabetes, hepatopatias, câncer, entre outras. Uma de suas propriedades é a atividade antioxidante, pois em pequenas quantidades é capaz de inibir ou retardar processos oxidativos. Para substanciar o estudo desta propriedade, comparou-se a capacidade de captura de espécies reativas radicalares e não radicalares pela curcumina, com padrões (biomoléculas, exceto o trolox) antioxidantes: ascorbato, crocina, glutationa, quercetina, rutina, trolox e urato, em sistemas-modelo in vitro, sobre a captura dos radicais: 2-2'-azino-bis (3-etilbenzotiazolina-6-ácido sulfônico) (ABTS●+ ); 2,2-difenil-1 picril-hidrazila (DPPH● ); ânion radical superóxido (O2 ●-); HOCl/OCl- e H2O2. Investigou-se também seu efeito inibitório na geração do HOCl no sistema, mieloperoxidase (MPO)/H2O2/Cl- (via clorinante) e na inibição da oxidação do guaiacol MPO/H2O2/Guaiacol (via peroxidativa). A curcumina nos ensaios com ABTS●+ ou O2 ●-, apresentou o 3° menor IC50, 4,93 e 99,66 µmol/L, respectivamente; com o DPPH● apresentou o 6° menor IC50, 24,70 µmol/L; com o HOCl/OCl- apresentou o menor IC50, 1,12µmol/L e no ensaio com o H2O2 não atingiu o IC50. No ensaio com o sistema MPO/H2O2/Cl-, observou-se alteração da banda de absorção (bleaching) da curcumina (420 nm), além disso, nos ensaios com a via clorinante (MPO/H2O2/Cl-) e revelados com 3, 3’, 5, 5’- tetrametilbenzidina (TMB) e iodeto de potássio em meio ácido, observou-se aumento da absorbância (650 nm), o que impossibilitou o estudo de sua inibição nesta via. Entretanto, na via peroxidativa, observou-se uma diminuição significativa da absorbância do produto de oxidação... (Resumo completo, clicar acesso eletrônico abaixo)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The ceramic pigments are colored inorganic substances that during the process of dispersion in the ceramic glazes and subsequent calcination, are stable against physical and chemical attack. Therefore, they are crystalline compounds applied in the ceramic industry for coloring vitreous base. In this study, the Pechini method was used for obtaining the pigment CuCr2O4 with heat treatment at the temperatures of 800, 900 and 1000 ° C. The powder pigments were characterized on their structural, morphological and colorimetric aspects. The thermal analysis conducted on an amorphous precursor in a TG / DTA indicates the weight loss in the entire temperature range investigated, with characteristic exothermic peak of the elimination of the organic composition of the precursor around 300°C. The development of the crystalline phases were investigated by XRD, using a diffractometer with Cu Ka radiation and graphite monochromator, where it was observed the presence of crystalline phases corresponding to Cr2O3 and CuCr2O4.The measurements of the specific surface area of the powders pigments were carried out in an equipment Micromeritcs, model ASAP 2000, using N2 as gas of adsorption/desorption. The colorimetric measurements of the pigments were made in a colorimeter Gretac Macbeth Color-eye spectrophotometer 2180 / 2180UV in CIELAB standards. Based on the obtained results, it can be verified the thermal stability of the powder pigments of green coloration, which enables it as an alternative to the materials currently used in the manufacture of ceramic tiles.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A ideia de uma nutrição que, além de suprir as necessidades nutricionais básicas do organismo também tem como objetivo a prevenção de doenças, ganha cada vez mais ênfase sobre a égide dos alimentos funcionais e dos nutracêuticos. Nesse contexto a curcumina, um pigmento amarelo-alaranjado extraído do rizoma da planta Curcuma longa L. se destaca como um promissor nutracêutico, apresentando um amplo potencial terapêutico e a cada dia encontra maior embasamento científico com a elucidação de seus mecanismos de ação sobre vários alvos moleculares importantes para a fisiopatologia de diversas doenças. A curcumina é bastante conhecida e explorada pela medicina asiática tradicional, principalmente pelas medicinas Ayurvédica e Chinesa. Utilizando o Pubmed e o Scielo como banco de dados para a pesquisa de trabalhos científicos, foi elaborada uma revisão bibliográfica com a compilação de estudos com diversos enfoques em relação à curcumina, a saber: i) características físico-químicas da curcumina; ii) propriedades anti-inflamatória, antioxidante, antidiabética, antitumoral, antiviral, antibacteriana, antiparasitária e antifúngica; iii) estratégias recentemente utilizadas para melhorar sua biodisponibilidade, tais como co-admnistração da piperina, síntese de análogos moleculares e sistemas inovadores de entrega como os sistemas coloidais (lipossomas e nanopartículas) e a complexação com ciclodextrina.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)