187 resultados para L-angle
Resumo:
The antioxidant activity of sugarcane (Saccharum officinarum L.) juice towards DPPH reagent was determined (EC50) and the main compounds with radical scavenging activity in juice and leaves extracts were identified by HPLC-UV/PAD analysis combined with HPLC microfractionation monitored by TLC using β-carotene and DPPH as the detection reagents. In sugarcane leaves, luteolin-8-C-(rhamnosylglucoside) (1) was the most important compound with radical scavenging activity; in sugarcane juice, the flavones diosmetin-8-C-glucoside (2), vitexin (3) schaftoside (9), isoschaftoside (10) and 4',5'-dimethyl-luteolin-8-C-glucoside (11) were the most relevant compounds. The content of juice flavonoids (0.241 ± 0.001 mg total flavonoids/mL juice), comparable to other food sources of flavonoids, suggest the potential of sugarcane as a dietary source of natural antioxidants. However, the low antioxidant ability of sugarcane juice (EC50 = 100.2 ± 2.6 g L-1) also points to the need for further studies about the dietary intake of sugarcane flavonoids and its effects on human health.
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We report the synthesis of single-phase, crystalline CdSiO3 nanostructures at 580ºC; to the best of our knowledge, this is the lowest temperature at which this material is reported to form. The desired phase does not form below 580ºC, since the diffraction peaks are shifted to lower angles in the material treated at 570ºC when compared to JDPDS Card No. 85-0310. The source of silicon has strong influence on the product morphology: Na2SiO3 yields single-phase CdSiO3 in needle-shaped nanostructures, while high surface area mesostructured SiO2 yields coralloid-shaped particles. Low angle X-ray diffractometry reveals that the mesostructured nature of the silica precursor is not maintained in the resulting CdSiO3. Scanning electron microscopy suggests that in this case a transition occurs between the spherical morphology of the precursor and the needle-shape morphology of the material prepared from Na2SiO3. The surface area of the silica precursor has a strong influence in the reaction, since the use of commercial silica with a lower surface area does not yield the desired product.
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Isosorbide succinate moieties were incorporated into poly(L-lactide) (PLLA) backbone in order to obtain a new class of biodegradable polymer with enhanced properties. This paper describes the synthesis and characterization of four types of low molecular weight copolymers. Copolymer I was obtained from monomer mixtures of L-lactide, isosorbide, and succinic anhydride; II from oligo(L-lactide) (PLLA), isosorbide, and succinic anhydride; III from oligo(isosorbide succinate) (PIS) and L-lactide; and IV from transesterification reactions between PLLA and PIS. MALDI-TOFMS and 13C-NMR analyses gave evidence that co-oligomerization was successfully attained in all cases. The data suggested that the product I is a random co-oligomer and the products II-IV are block co-oligomers.
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The aim of this study was to evaluate the effect of Tecoma stans L. Juss. ex Kunth seeds mass on initial emergence, growth and, seedling development under different light conditions. The seeds were separated in four mass classes and sowed in four replicates of 24 seeds for each class, under full sun and canopy shade. Under sun environment was observed a greater percentage of emergence. Heavy seeds presented the greater percentage of emergence under both environments, but a greater rate was observed under canopy shade. One month after the start of experiments, the seedlings at the shade environment presented 100% of mortality. The growth and development seedlings under full sun were noticed for five months. In this period, only in the first three months was possible to observe the effects of Tecoma stans seeds mass on capacity of seedlings to acquire dry mass. The seedlings biomass partitions were similar among the tested mass class. The seedlings of smaller mass tended to a high specific leaf area in relation to the seedlings from large seeds, mainly in the first three months, resulting in a great acquisition of dry mass by these seedlings. In the fourth month, the specific leaf area did not present any tendency. Because the biggest seeds to give rise seedlings with best initial development than smallest seeds can be considered as species reproductive strategy. To produce seeds of different sizes also can be considered as way of species to spread in many microhabitats.
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A new species of the genus Leporinus is described from the rio Araguaia, in Mato Grosso and Goiás states, Brazil. The new species has the dental formula 4/3, a unique feature within the genus; all other species of Leporinus have dental formulae 3/3, 3/4 or 4/4. In addition, the new species can also be distinguished by the following combination of characters: 36 to 37 scales in the lateral line, 4/4.5 or 4/5 series of scales in the transversal line, 16 circumpeduncular scale series, anal fin surpassing base of lower caudal-fin rays and three blotches along the lateral line. The new species shares with L. parae and L. lacustris a rather deep body, terminal mouth, long anal fin, three small dark blotches on the lateral line, the latter two, particularly the last one, usually fading, and preference for lentic habitats. Comments on the taxonomy and distribution of the species L. parae and L. lacustris are provided.
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O feijão caupi é uma das principais culturas alimentares do Nordeste brasileiro. Para melhorar sua resistência contra pragas e produtividade, a nova cultivar (BRS-Milênio) foi obtida por melhoramento genético. Este trabalho objetivou caracterizar o potencial nutricional desta variedade, determinando-se a composição centesimal, o perfil de aminoácidos e ácidos graxos, o conteúdo de minerais e a atividade inibitória de tripsina. A semente contém (g.100 g-1): 24,5 de proteínas; 51,4 de carboidratos; 16,6 de fibra insolúvel e 2,7 de fibra solúvel; 2,6 de cinzas, tendo como principais minerais (mg.100 g-1): ferro - 6,8; zinco - 4,1; manganês - 1,5; fósforo - 510,0 e potássio - 1430,0. O teor de lipídios foi de 2,2%, e seu perfil de ácidos graxos apresenta 29,4% de saturados e 70,7% de insaturados. Foi estimado valor calórico de 323,4 kcal.100 g-1 de semente. Encontrou-se baixa atividade inibitória de tripsina (8,0 UIT.mg-1 de amostra). O perfil de aminoácidos foi favorável ao padrão de referência, exceto pela deficiência de sulfurados, sugerindo a necessidade da combinação desta leguminosa com outras fontes alimentares. Os resultados indicam que o feijão caupi possui atributos desejáveis como altos teores de energia, proteínas, fibras e minerais, baixa atividade inibitória de tripsina e, apesar de reduzido conteúdo lipídico, contém alta proporção de ácidos graxos insaturados.
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A qualidade de luz pode alterar a morfogênese das plantas por meio de uma série de processos mediados por receptores de luz, principalmente na região do vermelho e azul. O objetivo do presente estudo foi verificar alterações anatômicas foliares e características biométricas de Cattleya loddigesii 'Tipo', cultivadas in vitro, sob diferentes malhas coloridas com nível de radiação de 50% de sombreamento. Plântulas oriundas de autopolinização e sementes germinadas in vitro, com aproximadamente 1,0cm de comprimento e com raízes, foram inoculadas em meio WPM e submetidas a diferentes condições de incubação. Testou-se o efeito de sombrites coloridos (vermelho e azul) sobre os frascos cultivados em casa de vegetação (CV) e sala de crescimento (SC), além dos tratamentos, nos dois ambientes, sem utilização das telas coloridas. A avaliação foi efetuada 180 dias após inoculação. Com os resultados obtidos, observou-se que o ambiente de cultivo promove alterações anatômicas e biométricas em plântulas de Cattleya loddigesii 'Tipo' micropropagadas. As alterações promovidas pelo cultivo em luz natural evidenciam maior capacidade fotossintética, por meio de maior diferenciação dos tecidos clorofilianos, promovendo uma superfície foliar anatomicamente adaptada à fase de aclimatização.
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Garlic contains polyphenol and sulphur compounds, which are responsible for its antioxidant activity (AA). This study aimed at evaluating the AA of fresh garlic and its commercialised products and their shelf life. Fresh garlic (FG) and its products, i.e. chopped with salt (CGS), chopped without salt (CG), fried (FRG) and mixed garlic (FG with dehydrated garlic; MG) antioxidant activity was evaluated by three different methods: DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, ß-carotene/linoleic acid assay and Rancimat® method. Amongst all the analysed products, fried garlic presented the highest antioxidant activity. The free radical-scavenging activity decreased during the shelf life of all analysed products that correlated with the decrease in the total polyphenol content. Our findings suggest that some compounds other than phenol may have contributed towards this outcome
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As características nutricionais, funcionais e agrícolas do amaranto são responsáveis pelo aumento do interesse por este alimento nas últimas décadas. O grão pode ser cozido, estourado, torrado, extrusado ou moído para ser consumido. Foi avaliado o efeito destes processamentos na atividade antioxidante do grão de amaranto, através das determinações do teor de fenólicos totais e da atividade antioxidante in vitro por dois métodos: inibição da oxidação lipídica pelo sistema \03B2-caroteno/ácido linoléico e índice de atividade antioxidante pelo aparelho Rancimat®. Os processamentos reduziram em média o teor de fenólicos totais do grão de amaranto de 31,7 para 22,0 mg de equivalentes de ácido gálico/g de resíduo seco. Observou-se que o extrato obtido por etanol do grão torrado foi o único a apresentar menor índice de atividade antioxidante (IAA) em relação ao grão cru (1,3 v 1,7). Os processos de extrusão, torração e explosão não alteraram a capacidade de inibição da oxidação lipídica (IOL) do amaranto (55 por cento). Já o cozimento aumentou o IOL (79 por cento), o que pode ter ocorrido devido ao maior tempo de processamento sob alta temperatura (100ºC/10min). Os métodos mais comuns de processamento do grão de amaranto ocasionaram redução do teor de fenólicos totais, no entanto a atividade antioxidante do estourado e do extrusado, avaliada pelos dois métodos, foi semelhante ao do grão cru. O grão de amaranto tanto cru como processado apresenta potencial antioxidante. Polifenóis, antocianinas, flavonóides, tocoferóis, vitamina C e compostos gerados na reação de Maillard podem estar relacionados à atividade antioxidante deste grão
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Cardiovascular disease is a serious public health problem; it is the first cause of death in Brazil and in developed countries. Thus, it is essential to search for alternative sources such as some functional foods to prevent and control the risks of this disease. The purpose of this study was to evaluate the lipidemic parameters in hypercholesterolemic rats fed diets containing black rice variety IAC 600 or unrefined rice. Adult male Wistar rats (Rattus norvegicus var. albinos) were used, weighing about 200-220 g. The animals were divided into four groups: the first received a control casein diet, the second received hypercholesterolemic diet, and the other two groups, after induction of hypercholesterolemia, received the test diets, the first containing 20% black rice and the second 20% unrefined, for 30 days. It was observed that diet containing black rice reduced the level of plasma cholesterol, triglycerides, and low-density lipoprotein. For high-density lipoprotein values, the diet that provided an increase in the levels was the black rice. The diet containing black rice was more effective in controlling the lipidemia in rats compared with the whole rice diet.
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Three morphotypes of aguaje Mauritia flexuosa were tested, classified by the color of their mesocarpium: ""color"", ""shambo"" and ""amarillo"", collected from different areas near the city of Iquitos, Peru. Also, physical-chemical analyses of the mesocarpium were performed, such as the characterization of fatty acids by gas chromatography, determination of beta- carotene y alpha tocopherol by high efficiency liquid chromatography system in normal and reverse phase and the determination of oxidation induction time in the Rancimat apparatus. Proximate, mineral and fatty acid analyses were done on the seeds. The aguaje mesocarpium is rich in oleic oil (""amarillo"": 75.63% +/- 0.31), (beta-carotene (""amarillo"": 342.42ug/g 0.71) and alpha- tocopherol (""color"": 685.81mg/L +/- 1.04), plus the morphotype ""color"" has a superior oxidation induction time compared to other morphotypes with 6.91 +/- 0.01. The aguaje seed contains significant amounts of (06 (linoleic oil) in ""shambo"" with 36.04 +/- 0.09%. The results indicate that these oils, regardless their classification, contain important chemical compounds that give them a special nutritive value.
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The synthesis of [Ru(NO(2)) L(bpy)(2)](+) (bpy = 2,2'-bipyridine and L = pyridine (py) and pyrazine (pz)) can be accomplished by addition of [Ru(NO) L(bpy) 2](PF(6))(3) to aqueous solutions of physiological pH. The electrochemical processes of [Ru(NO2) L(bpy) 2]+ in aqueous solution were studied by cyclic voltammetry and differential pulse voltammetry. The anodic scan shows a peak around 1.00 V vs. Ag/AgCl attributed to the oxidation process centered on the metal ion. However, in the cathodic scan a second peak around-0.60 V vs. Ag/AgCl was observed and attributed to the reduction process centered on the nitrite ligand. The controlled reduction potential electrolysis at-0.80 V vs. Ag/AgCl shows NO release characteristics as judged by NO measurement with a NO-sensor. This assumption was confirmed by ESI/MS(+) and spectroelectrochemical experiment where cis-[Ru(bpy)(2)L(H(2)O)](2+) was obtained as a product of the reduction of cis-[Ru(II)(NO(2)) L(bpy)(2)](+). The vasorelaxation observed in denuded aortic rings pre-contracted with 0.1 mu mol L(-1) phenylephrine responded with relaxation in the presence of cis-[RuII(NO2) L(bpy) 2]+. The potential of rat aorta cells to metabolize cis-[RuII(NO(2)) L(bpy)(2)](+) was also followed by confocal analysis. The obtained results suggest that NO release happens by reduction of cis-[RuII(NO(2)) L(bpy)(2)](+) inside the cell. The maximum vasorelaxation was achieved with 1 x 10(-5) mol L(-1) of cis-[RuII(NO(2)) L(bpy)(2)](+) complex.
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Despite the valuable contributions of robotics and high-throughput approaches to protein crystallization, the role of an experienced crystallographer in the evaluation and rationalization of a crystallization process is still crucial to obtaining crystals suitable for X-ray diffraction measurements. In this work, the difficult task of crystallizing the flavoenzyme l-amino-acid oxidase purified from Bothrops atrox snake venom was overcome by the development of a protocol that first required the identification of a non-amorphous precipitate as a promising crystallization condition followed by the implementation of a methodology that combined crystallization in the presence of oil and seeding techniques. Crystals were obtained and a complete data set was collected to 2.3 A resolution. The crystals belonged to space group P2(1), with unit-cell parameters a = 73.64, b = 123.92, c = 105.08 A, beta = 96.03 degrees. There were four protein subunits in the asymmetric unit, which gave a Matthews coefficient V (M) of 2.12 A3 Da-1, corresponding to 42% solvent content. The structure has been solved by molecular-replacement techniques.
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Objective: To evaluate the effects of local administration of epidermal growth factor (EGF) located within liposomes on recruitment of osteoclasts during mechanical force in rats. Materials and Methods: An orthodontic elastic band was inserted between the left upper first and second molars, to move mesially the first molar. Rats were randomly divided into 4 groups (n = 8): EGF (2 ng/mu L) located within liposomes (group 1), liposomes only (group 2), soluble EGF (2 ng/mu L; group 3), or vehicle alone (group 4). The solutions were injected into the region of the root furcation of the left first molar after elastic band insertion. Tooth movement was measured using a plaster model of the maxilla, and the number of osteoclasts recruited at the pressure side of the first molar was histologically evaluated. Results: Intergroup analysis showed that there was no significant difference between group 2 and group 4 (P >.05) and between group 1 and group 3 (P >.05). However, group 1 and group 3 exhibited greater differences in tooth movement than group 2 and group 4 (P <.05). On the other hand, group 1 showed greater tooth movement than groups 2 and 4 with statistical significance (P <.01). The increase in the number of osteoclasts in group 1 was significantly higher than in the other groups (P <.05). Conclusion: Exogenous EGF-liposome administration has an additive effect when compared with soluble EGF on the rate of osteoclast recruitment, producing faster bone resorption and tooth movement.
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We developed a method for rearing larvae of Africanized bees under laboratory conditions to determine the amount of diet needed during larval development to obtain a worker bee. We started with larvae 18-24 h old, which were transferred to polyethylene cell cups and fed for five days. We found that the amount of diet needed for successful larval development was: 4, 15, 25, 50, and 70 mu L during the first to fifth days, respectively. The survival rate to the adult stage was 88.6% when the larvae received the daily amount of diet divided into two feedings, and 80% when they received only one feeding per day. The adult weight obtained in the laboratory, when the larvae received the daily amount of diet in a single dose, did not differ from those that were developed under field conditions (our control). All adults that we obtained in laboratory appeared to be normal. This technique has the potential to facilitate studies on brood pathogens, resistance mechanisms to diseases and also might be useful to test the impacts of transgenic products on honey bee brood.