959 resultados para Ana
Resumo:
In the context of quality and good laboratory practices, the article recovers some historical data. From a specific Institutional situation (CPQBA/UNICAMP), is presented an experience of establishing and implementing a standard (NIT-DICLA-035) for good laboratory practice according to definitions of the Brazilian authority (INMETRO) responsible for regulating, monitoring, supervising and recognition in this area. The issue aims to focus on studies of pesticide residues in GLP parameters.
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A new practical experiment involving silver and gold nanoparticle syntheses was introduced in an inorganic chemistry laboratory course for undergraduate students at the Institute of Chemistry, UNICAMP. The nanoparticles were synthesized by the reduction of silver nitrate and tetrachloroauric acid with sodium borohydride and sodium citrate in an aqueous medium. Stabilities of the suspensions were tested using several different reactants including sodium chloride, polyvinylpyrrolidone, polyvinyl alcohol and cistamine. Changes in optical properties were observed by electronic spectra and also by transmission electronic microscopy, which also yielded data for estimating particle size.
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A simple analytical method for extraction and quantification of lutein colorant added to yogurt was developed and validated. The method allowed complete extraction of carotenoids using tetrahydrofuran in vortex, followed by centrifugation, partition to diethyl ether/petroleum ether, and drying. The carotenoids dissolved in ethanol were quantified by UV-Vis spectrophotometry. This method showed linearity in the range tested (1.41-13.42 µg g-1), limits of detection and quantification of 0.42 and 1.28 µg g-1, respectively, low relative standard deviation (3.4%) and recovery ranging from 95 to 103%. The method proved reliable for quantification of lutein added to yogurt.
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Arrabidaea chica (H&B) Verlot is a plant popularly known as Pariri and this species is a known source of anthocyanins, flavonoids and tannins. This report describes an approach involving enzymatic treatment prior to extraction procedures to enhance A chica crude extract anticancer activity. Anticancer activity in human cancer cell lines in vitro using a 48 h SRB cell viability assay was performed to determine growth inhibition and cytotoxic properties. The final extraction yield without enzyme treatment was higher (24.28%) compared to the enzyme-treated material (19.03%), with an enhanced aglycones anthocyanin ratio as determined by HPLC- DAD and LC-MS with direct infusion.
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The main objective of this work is the study of the effect of rice husk addition on the physical and mechanical properties of soil-cement, in order to obtain an alternative construction material. The rice husk preparation consisted of grinding, sieving, and the pre-treatment with lime solution. The physical characteristics of the soil and of the rice husk were determined. Different amounts of soil, cement and rice husk were tested by compaction and unconfined compression. The specimens molded according to the treatments applied to the mixtures were subsequently submitted to compression testing and to tensile splitting cylinder testing at 7 and 28 days of age and to water absorption testing. After determining its physical and mechanical characteristics, the best results were obtained for the soil + 12% (cement + rice husk) mixture. The results showed a promising use as an alternative construction material.
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Fresh tomato harvest is traditionally made without harvesting aids. The main goal of this research was to evaluate performance parameters of fresh tomato harvesting aid equipment and compare it to traditional harvest, in the state of São Paulo. Therefore, an equipment was developed and the harvest process was evaluated in four different ways: traditional system (harvest system used in Santa Luzia farm, Brotas, SP, Brazil), picker walking with a harvesting aid equipment, picker seated in a harvesting aid equipment and a composition of both systems: two pickers seated and one picker walking in two different velocities ranges. The different systems using harvesting aid showed an average yield by picker more efficient than reference. Harvest system using three pickers showed an increase of 290% on yield average by picker, on the range of 0.5-1.0 fruit per plant, followed by the systems with a walking picker, that increased productivity in 41%, and picker seated harvester, that showed an increase of 35%. These results demonstrate the importance of using a harvesting aid equipment.
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On the last years, in Brazil, sorting and classifying fruits and vegetables using packing lines have increased. This work aimed at characterizing the cleaning process for fresh market tomatoes at two packing lines, one imported and one national located at Campinas, São Paulo State. Characterization included data, number, types and brushes velocity, water use, fruit standing time and cleaning efficiency. Standing time was measured correlating to fruit diameter (CEAGESP). For measuring cleaning efficiency an equipment was developed that was mainly composed of a ring involved with white cloth. Samples were taken before and after the cleaning step and evaluated using a colorimeter HUNTER Lab. The results showed a strong difference between the two equipments. The imported equipment showed lower number on brushes and rotation than national one, however a higher water consumption. For imported equipments this relation was not found. Both packing lines showed the same cleaning efficiency. Cleaning efficiency is related to be an interaction among the studies parameters, and it could be necessary a better management than the one used on both equipments.
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The post-harvesting cleaning process in fresh market tomatoes production is essential to the consumer acceptance, since the degree of dirtiness of the fruits is directly related to its quality. However, the washing stage of the cleaning process of commercial packinghouse demands an excessive water volume, bringing serious environmental concerns. The objective of this work was to compare the cleaning efficiency in two cleaning systems through the evaluation of different operational conditions of the cleaning process, related with the brush rotation, water flow and fruit standing time under the system. It was compared the conventional system utilized in commercial equipment with a system using commercial sprays. The results showed that the cleaning efficiency was not directly related to the water volume used, but to the water pressure, standing time and brushes rotation. Therefore, the use of commercial sprays can bring benefits to the cleaning efficiency, increasing it up to 13%, and to the environmental, decreasing water consumption.
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This article analyzes food insecurity and hunger in Brazilian families with children under five years of age. This was a nationally representative cross-sectional study using data from the National Demographic and Health Survey on Women and Children (PNDS-2006), in which the outcome variable was moderate to severe food insecurity, measured by the Brazilian Food Insecurity Scale (EBIA). Prevalence estimates and prevalence ratios were generated with 95% confidence intervals. The results showed a high prevalence of moderate to severe food insecurity, concentrated in the North and Northeast regions (30.7%), in economic classes D and E (34%), and in beneficiaries of conditional cash transfer programs (36.5%). Multivariate analysis showed that the socioeconomic relative risks (beneficiaries of conditional cash transfers), regional relative risks (North and Northeast regions), and economic relative risks (classes D and E) were 1.8, 2.0 and 2.4, respectively. Aggregation of the three risks showed 48% of families with moderate to severe food insecurity, meaning that adults and children were going hungry during the three months preceding the survey.
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This paper describes a method for leaf vein shape characterization using Hermite polynomial cubic representation. The elements associated with this representation are used as secondary vein descriptors and their discriminatory potential are analyzed based on the identification of two legume species (Lonchocarpus muehlbergianus Hassl. and L. subglaucescens Mart, ex Benth.). The elements of Hermite geometry influence a curve along all its extension allowing a global description of the secondary vein course by a descriptor of low dimensionality. The obtained results shown the analyzed species can be discriminated by this method and it can be used in addition to commonly considered elements in the taxonomic process.
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This work is a floristic survey of arboreous and climbing shrub taxa of Papilionoideae in a semideciduos forest at Parque Estadual do Rio Doce, eastern Minas Gerais State. Field work was carried out from April/1998 to May/1999, when montly visits were conducted to collect botanical material along trails and of the main road. The floristic survey resulted in 22 taxa belonging to eight genera. An identification key, descriptions, illustrations and comments on the analyzed taxa are presented.
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In Myrocarpus, an exclusively South American genus, five species are recognised: Myrocarpus frondosus Allemão, M. leprosus Pickel, M. venezuelensis Rudd, M. fastigiatus Allemãoand M. emarginatus A.L.B. Sartori & A.M.G. Azevedo. Morphologic data, habitat information and geographic distribution of each taxon are discussed. Petal morphology and ornamentation of seed chamber are an important character for species identification, though not shown previously. Key to the species, descriptions, illustrations, distribution, and new registers are presented.
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A study of the tree species of the order Celastrales sensu Cronquist from the Tibagi river basin, Paraná state, Brazil, is presented, based on herbarium material. This basin is subdivided into three zones, from north to south: lower Tibagi (BT), mid Tibagi (MT) and upper Tibagi (AT), each with different environmental conditions and vegetation types. The order Celastrales is represented in the basin by 15 tree species belonging to three families: Aquifoliaceae, Celastraceae and Icacinaceae. Icacinaceae has only two species, Citronella gongonha and C. paniculata. The former is distinguished by a glabrous ovary and leaves that usually bear thorns. Aquifoliaceae has six species: Ilex brasiliensis, I. brevicuspis, I. chamaedryfolia, I. dumosa, I. paraguariensis and I. theezans. These species are found mainly in AT and MT and are distinguished by leaf size, indument, apices and margins, and by sepal features. Celastrales is represented by seven species and two genera; Plenckia populnea, a Brazilian savannah species found only in MT, and six species of Maytenus (M. evonymoides, M. robusta, M. dasyclada, M. salicifolia, M. ilicifolia and M. aquifolia) distinguished by leaf size and margins, branch shape and number of flowers per inflorescence.
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This work aims to describe, illustrate and compare the seedling morphology of five tree species of the genera Bowdichia, Cyclolobium, Diplotropis, Ormosia, and Poecilanthe, which belong to the genistoid clade (Leguminosae Papilionoideae). Phanero-epigeal-foliaceous seedlings are found in Bowdichia virgilioides Kunth, Cyclolobium brasiliense Benth. has phanero-epigeal-reserve seedlings, while Ormosia arborea (Vell.) Harms, Diplotropis martiusii Benth., and Poecilanthe parviflora Benth. possess crypto-hypogeal-reserve seedlings. Some other relevant seedling morphological characters are discussed and compared with those of previously studied species in these genera.
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The study assessed phloem canal development and ultra-structure in shoot apices of Spondias dulcis G. Forst., phloematic canal ultra-structure in shoot apices of Tapirira guianensis Aubl., and floral canal ultra-structure and development and fruit canal ultra-structure of the latter specie. The flower and fruit canals of Anacardium humile St.Hil. were also studied ultra-structurally. The canals in shoot apices of S. dulcis show schizo-lysigenous formation and the floral canals of T. guianensis show schizogenous development. Epithelial cells of S. dulcis and T. guianensis canals have rough endoplasmic reticulum, free ribosomes, elongated plastids of several shapes with osmiophilic inclusions and dictyosomes with production of vesicles. Such organelles participate in the secretion of a heterogeneous exudate, which is comprised of hydrophilic and lipophilic substances. The epithelial cells of the fruit of A. humile present elongated plastids with circular membrane system, which are involved in the synthesis of lipophilic substances. The results of the ultra-structural analyses of the epithelial cells corroborate the results previously obtained in a histochemical study. In the histochemical study, lipophilic and hydrophilic substances were identified in the canals of T. guinanensis and S. dulcis and only lipophilic substances were identified in the canals of A. humile. Based on the ultrastructural aspects of the secretory canals of T. guianensis and S. dulcis we concluded that the plastids of the epithelial cells of the two species are different although they produce secretion of similar composition. A new record for the family is the presence of a great number of circular plastids in epithelial cells of the fruit of Anacardium humile. The pattern found in the secretory canals of the studied species is the ecrine type of secretion release.