180 resultados para Total Electron Content (TEC)


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The Hymenoptera Aculeata venoms, with few exceptions, have been poorly studied and characterized. Nevertheless, they have raised increasing interest due to their medical importance, since accidents with these insects are fairly frequent in Brazil and may cause severe allergic reactions. The objectives of the present work were the quantitative characterization of the main allergenic enzymes present in the venom of the species Polybia paulista, Polybia ignobilis, Polistes simillimus, and Agelaia pallipes pallipes through biochemical assays for the determination of total protein content, as well as the level of the enzymatic activity of phospholipase, hyaluronidase, acid phosphatase and esterase. These results, in addition to providing biochemical knowledge about the venom of the species in question, also supply studies that allow phylogenetic inferences among them.

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Caseins comprise make up about 80% of the total protein content of milk and present polymorphism with change in the amino acid sequence. Within this abundance of proteins, kappa-casein is noteworthy, since it has been associated with differences in milk yield, composition and processing. The objective of this study was to observe the existence of polymorphism in the kappa-casein gene in female buffaloes. For this purpose, blood samples from 115 female buffaloes, collected with vacutainer by needle punctionure of the jugular vein, were used. for genomic DNA extraction was done from blood samples. The PCR-RFLP and SSCP techniques demonstrated that the studied animals were monomorphic for the kappa-casein gene. Only allele B was observed in these animals, which was present in homozygosis. Therefore, it was not possible to quantify the gene action on milk yield and its constituents. The monomorphism observed in the population studied would allow the development of a method to identify mixtures of cow and buffalo milk in mozzarella cheese production, especially because, in cattle, the kappa-casein gene is polymorphic. Copyright by the Brazilian Society of Genetics.

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This paper describes a chemical investigation (by high-speed counter-current chromatography) of an extract in methanol of the capitula (flower-heads) of the endemic Brazilian herb Leiothrix flavescens (Bong.) Ruhland (Eriocaulaceae). Fractionation of this extract by preparative chromatography and identification of the isolated compounds by spectrometric methods (IR, UV, ESI-MS, NMR) led to the identification of flavones (apigenin, luteolin and 6-methoxyluteolin) and 1,3-di-O-feruloyl glycerol. The antioxidant activity of the extract was determined by DPPH reduction and the total phenolic content by the Folin-Ciocalteau assay. It was found that the methanolic extract of L. flavescens possesses strong antioxidant activity. Additionally, the chemical profile provided useful data for a discussion of the taxonomy of the Eriocaulaceae.

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This study aimed to characterize the pulp and kernel of guariroba (Syagrus oleracea), jerivá (Syagrus romanzoffiana) and macaúba (Acrocomia aculeata) palm fruits, through their proximate composition, carotenoids contents and tocopherol composition. The three kernels showed to be composed mainly of lipids and proteins, as the three pulps, of carbohydrate and fiber. In the kernels the levels of lipids ranged from 45.17 to 56.37% and proteins from 15.46 to 28.61%. In the pulps the total fiber content ranged from 20.26 to 26.98%. The pulps also presented a significant amount of ash, which represents a significant mineral content, especially in the guariroba (5.16%). Moreover, the pulp oils showed higher carotenoids and tocopherol contents. The jerivá pulp oil contained carotenoid and tocopherol on average 1219 μg/g and 323.50. mg/kg, respectively. The consumption of the whole fruit, pulp, and kernel supplies important quantities of many necessary nutrients for human diet, including vitamins A and E. © 2011 Elsevier Ltd.

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The experiment was developed based on the importance of the nutritional factor cunhã for large and small, animals and on the growth of this forage in typical soils of the semiarid region, generally with salinity from natural or anthropogenic action. The experiment was performed in vessels with a capacity of 5kg prepared in a protected environment with full sunshine in the Department of Technology and Social Sciences (DTCS) of UNEB Campus III in Juazeiro - BA. It evaluated the effect of seven different salt concentrations on increasing levels of irrigation water electrical conductivity - ECw (0, 2, 4, 6, 8, 10 and 12 dS/m), at room temperature. The analysis of culture were taken every seven days observing the number of leaves, stem diameter, plant, plant length and total chlorophyll content at 13; 20; 27; 34 and 40 days after the start of irrigation with saline. The contents of proline, the ratio aero part/Root (AP/Rt), the root length and water content were evaluated in the 40 th day after the onset of treatment. The results showed that the elevation of ECw affected all variables.

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Carpolobia lutea leaves (CLL) (Polygalaceae) were earlier screened and the antiulcer ethnomedicinal claim established. This article seeks to quantitatively isolate, elucidate the active compounds from most active CLL fraction. Fractionation was by semi-preparative HPLC; the active fraction was subjected to radical scavenging assays (RSA) and quantification of the total phenolic content (TPC) were also executed. Results: Ethyl acetate fraction (EAF) was observed to be the most pharmacologically active antiulcer fraction when screened using acute ulcer models induced in rodents. The EAF demonstrated significant (p < 0.05-0.001) antiulcer activity in various in vivo induced ulceration models by reducing the ulcer index and increasing the preventive ratio. The EAF demonstrated > 70% in TPC and < 20 % in RSA. Cinnamic and coumaric acids derivatives were isolated from EAF. Cinnamic acids have been implicated and patented as antiulcer agent. Isolated compounds could in part mediate the observed pharmacological activities which lend credence to its ethnobotanical uses.

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The objective of this study was evaluate the effect of the log steaming on the chemical properties and decay resistance of Eucalyptus grandis wood. Logs with diameter between 20 and 22 cm were studied. Half of logs were kept in its on original condition, and the other half was steamed at 90°C for 13 hours. The holocellulosc, Klason lignin, total extractives content and the weight loss caused by the decay fungus Pycnoporus sanguineous were characterized. The results showed that the log steaming of E. grandis wood cause: (l)a significantly decreased in holocellulose content; (2) an increase of 4.8% and 4.4% in total extractives and lignin content, respectively; and (3) a decrease in its durability against the decay fungus P. sanguineus in order of 13.03%. Copyright © (2012) by WCTE 2012 Committee.

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Sugarcane cultivars show varying degrees of herbicide susceptibility, with herbicide effects ranging from no injury to total plant eradication. In this study, phenotypic and biochemical responses to glyphosate were evaluated in three sugarcane cultivars. Herbicide tolerance of the three cultivars (IACSP93-3046, IACSP94-4004 and RB72454) was tested in a greenhouse experiment using a completely randomized design. The experiment consisted of four replications of treatments in a factorial arrangement of 3 cultivars × 6 glyphosate dosages (0, 1,440, 2,160, 2,880, 3,600 and 4,320 g a. e. ha-1). Intoxication symptoms, based on a percentage scale ranging from 0 (no injury) to 100 % (total plant death), and total chlorophyll content were recorded at 1, 2, 3, 6, 7, 10, 20 and 34 days after glyphosate application (DAA). Shikimate dehydrogenase and α-esterase isoenzyme assays were performed at 8, 24, 48, 72 and 144 h after application (HAA). Intoxication symptoms observed at 6 DAA ranged from 5 % at the lowest glyphosate dosage (1,440 g a. e. ha-1) to ~30 % at the highest dosage (4,320 g a. e. ha-1) across all cultivars. IACSP94-4004 and IACSP93-3046 were determined to be the most glyphosate-tolerant cultivars. Reduction in chlorophyll content was observed with high dosages of glyphosate at 6 DAA. The shikimate dehydrogenase banding pattern was generally conserved among cultivars and treatments, with the exception of the IACSP94-4004 cultivar, which showed alterations in the banding pattern of α-esterase after glyphosate application. © 2013 Society for Sugar Research & Promotion.

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Physico-chemical characteristics, fatty acid and tocopherol compositions, total phenolic content and antioxidant activity of crude oil extracted from guava (Psidium guajava var. pomifera) seeds were investigated. Oil yield from the seeds was 14.0%. Data obtained for the analytical indexes compared well with those of others edible oils. The oil showed high levels of unsaturated fatty acids (88.1%), mainly linoleic acid (78.4%). The tocopherol and total phenolic contents in the oil amounted to 29.2 and 92.3 mg/100 g, respectively. The guava seed oil exhibited a great DPPH · scavenging activity showing EC50 of 12.9 g oil/g [DPPH · ] -1 and antiradical efficiency of 7.9×10 -2 . Therefore, the potential utilization of the guava seed oil as a raw material of food, chemical and pharmaceutical industries appears to be favourable and provides the use of a renewable resource, adding value to agricultural products.

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Four different assays (the Folin-Ciocalteu, DPPH, enzymatic method, and inhibitory activity on lipid peroxidation) based on radically different physicochemical principles and normally used to determine the antioxidant activity of food have been confronted and utilized to investigate the antioxidant activity of fruits originated from Brazil, with particular attention to more exotic and less-studied species (jurubeba, Solanum paniculatum; pequi, Caryocar brasiliense; pitaya, Hylocereus undatus; siriguela, Spondias purpurea; umbu, Spondias tuberosa) in order to (i) verify the correlations between results obtained by the different assays, with the final purpose to obtain more reliable results avoiding possible measuring-method linked mistakes and (ii) individuate the more active fruit species. As expected, the different methods give different responses, depending on the specific assay reaction. Anyhow all results indicate high antioxidant properties for siriguela and jurubeba and poor values for pitaya, umbu, and pequi. Considering that no marked difference of ascorbic acid content has been detected among the different fruits, experimental data suggest that antioxidant activities of the investigated Brazilian fruits are poorly correlated with this molecule, principally depending on their total polyphenolic content. © 2013 Elena Gregoris et al.

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The objective of this study was to evaluate the association between the physicochemical properties and sensory acceptance of Brazilian red wines by applying chemometric techniques. Therefore, three winemaking processes were carried out: a traditional winemaking process and two novel winemaking processes, pre-drying and static pomace. Significant differences could be identified amongst the physicochemical properties of the wines (P<0.001). The sensory results showed greater acceptance of the wines made after pre-drying of the grapes or from the static pomace, as compared to commercial brands. Cluster analysis and Multidimensional Scaling were successfully applied and their results demonstrated the influence of the total phenolic content and color indexes on acceptance of the appearance of the wines. The odor was associated with the alcohol content, acidity, dry extract, total and reducing sugars and the body of the wines. The flavor was associated with several physicochemical properties which influenced the overall acceptance of the samples. © 2013 Elsevier Ltd.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)