141 resultados para Criação de conceitos
Resumo:
O objetivo deste trabalho foi avaliar o efeito de dieta, com inclusão de um núcleo energético-proteico (NEP) de alta digestibilidade, no desempenho produtivo e características de carcaça de frangos de corte. O NEP constituiu-se de composto de óleo degomado de soja, milho pré-gelatinizado, soja biprocessada, mananoligossacarídeos e peptídeos. O total de 864 pintainhos machos, da linhagem AgRoss 508, com um dia de idade, foram pesados individualmente e distribuídos em blocos ao acaso. Os tratamentos consistiram de suplementos com diferentes teores de NEP, com oito repetições com 27 aves cada: T1, controle, 0% de NEP; T2, 7% de NEP (1-7 dias) e 3,5% de NEP (8-21 dias); T3, 14% de NEP (1-7 dias) e 7% de NEP (8-21 dias); e T4, 21% de NEP (1-7 dias) e 10,5% de NEP (8-21 dias). Aos 21 dias de idade, o peso corporal, ganho de peso, consumo médio de ração, conversão alimentar e rendimento de carcaça e cortes não foram afetados significativamente pelos tratamentos experimentais. A utilização de NEP na dieta de frangos de corte não altera o desempenho das aves e não interfere nas variáveis de características de carcaça.
Resumo:
O objetivo deste trabalho foi adequar as dietas artificiais para o desenvolvimento dos estágios de larva e adulto da mosca-das-frutas sul-americana (Anastrepha fraterculus). Para o estágio larval, foram testadas as seguintes dietas: D1, original, com 10 g de ágar; D2, modificada, com 3,6 g de ágar; e, D3, modificada, com bagaço seco de cana-de-açúcar. Para os adultos, foram testadas quatro dietas: A, levedura de cerveja + mel (2:1); B, açúcar refinado + extrato de levedura + gérmen de trigo cru (3:1:1); C, extrato de soja + açúcar mascavo + gérmen de trigo cru (3:1:1); e D, levedura seca de cervejaria + mel (2:1). Avaliaram-se os parâmetros biológicos de duração do período ovo-pupa, duração e viabilidade do estágio de pupa, massa média de pupas, razão sexual e duração e viabilidade do período ovo-adulto. O desenvolvimento larval em D1 e D2 foi semelhante e indicou que a criação de larvas pode ser realizada com 1/3 da quantidade de ágar da utilizada em D1. A utilização do bagaço seco de cana-de-açúcar, na dieta artificial, afetou negativamente o desenvolvimento larval. As dietas artificiais com levedura de cerveja + mel e com açúcar refinado + extrato de levedura + gérmen de trigo cru são as mais adequadas para a criação de adultos.
Resumo:
Considerada praga-chave da cultura da goiaba, Conotrachelus psidii Marshall (Coleoptera: Curculionidae) tem causado grandes prejuízos em vários países produtores desta fruta. A pesquisa objetivou avaliar os parâmetros biológicos da praga, sob condições controladas, através do desenvolvimento de uma técnica de criação que permitiu efetuar observações diárias de pré-pupas e pupas. Constatou-se que o substrato adequado para manutenção dessas fases foi o solo argiloso umedecido com viabilidade de 78%, sendo este o tipo de solo utilizado na técnica de criação, que foi desenvolvida para trabalhos em câmara climatizada, à temperatura constante de 25 ± 1º C, fotoperíodo de 12 horas e UR de 70% ± 10%. Quanto aos aspectos biológicos, a duração média do período de ovo, larva, pré-pupa, pupa e ovo-pupa foi de: 4,25; 12,2; 106,6; 14,88 e 138,4 dias, respectivamente. A duração média do período da fase adulta, no solo, início da alimentação, pré-oviposição, longevidade e pós-oviposição foi de, 22; 11; 51,9; 149,32 e 7,18 dias, respectivamente. O período médio de oviposição foi de 120,27 dias, com um número médio de 343,63 ovos por fêmea. A técnica de criação desenvolvida permitiu acompanhar diariamente o desenvolvimento de pré-pupas, pupas e adultos do gorgulho-da-goiaba, sem que eles necessitassem reconstruir nova câmara, mostrando ser menos estressante e onerosa do ponto de vista energético.
Resumo:
A pancreatite aguda é uma condição inflamatória causada por ativação intracelular e extravasamento inapropriado de enzimas proteolíticas que determinam destruição do parênquima pancreático e dos tecidos peripancreáticos. Consiste em uma condição clínica bastante frequente, identificando-se duas formas principais de apresentação: a forma edematosa, menos intensa, e a forma necrosante, a forma grave da doença que acomete uma proporção significativa dos pacientes. A avaliação radiológica, sobretudo por tomografia computadorizada, tem papel fundamental na definição da conduta nos casos graves, sobretudo no que diz respeito à caracterização das complicações locais, que têm implicação prognóstica, e na determinação do tipo de abordagem terapêutica. Novos conceitos incluem a subdivisão da pancreatite necrosante nas formas de necrose do parênquima pancreático concomitante com necrose dos tecidos peripancreáticos ou necrose restrita aos tecidos peripancreáticos. Além disso, houve sistematização dos termos: acúmulos líquidos agudos peripancreáticos, pseudocisto, alterações pós-necróticas pancreáticas/peripancreáticas e necrose pancreática delimitada. Tal conhecimento é de extrema relevância no sentido de uniformizar a linguagem entre os especialistas envolvidos no diagnóstico e tratamento desses pacientes.
Resumo:
The main objectives of this article are to present and discuss the facts that lead to the conception of JBCS in 1987, its birth in 1990 and the stages traveled until its consolidation. The community's of Chemistry participation and the role of the Sub-program of Chemistry and Chemical Engineering of PADCT are emphasized.
Resumo:
In the present paper we discuss, based in our experience, some experimental procedures which may be employed for isolation of active compounds from medicinal plants. We have also emphasized some insights about the way to obtain more active and selective compounds from natural products through structural modifications oriented for analysis of structure-activity relationships.
Resumo:
Chemical Technology and Fine Chemicals, in the sense we understand them, go back not to Leblanc's soda production process, as many historians of Science and chemists suggest, but to the XVIIth Century, with the "technological" activities of Glauber and others; the Paracelsian Thurneisser can be seen as the first to produce "fine chemicals".
Resumo:
For economical and ecological reasons, synthetic chemists are confronted with the increasing obligation of optimizing their synthetic methods. Maximizing efficiency and minimizing costs in the production of molecules and macromolecules constitutes, therefore, one of the most exciting challenges of synthetic chemistry. The ideal synthesis should produce the desired product in 100% yield and selectivity, in a safe and environmentally acceptable process. In this highlight the concepts of atom economy, molecular engineering and biphasic organometallic catalysis, which address these issues at the molecular level for the generation of "green" technologies, are introduced and discussed.
Resumo:
Under the chromatographic point of view, the physico-chemical properties of a supercritical fluid are intermediate to those of the gases and liquids. Many times they approach the best features of each one, as for example, the solubilization power of liquids and low viscosity of gases. The thermodynamic definitions and main physico-chemical features of a supercritical fluid will be presented in this article. The use of supercritical fluids in analytical chemistry has been extremely modest in Brazil, even considering the enormous potential of their applications, and their use in several techniques, such as chromatography (SFC) and supercritical fluid extration (SFE). This article series is intended to discuss the historical evolution, instrumentation features and potential and limitations of the supercritical fluid use in analytical chemistry. A special focus will be centered on chromatography and extration techniques using supercritical fluids.
Resumo:
The microwave oven became a common domestic equipment, due mainly to the short time spent to heat foods. One of the most interesting characteristics of the microwave oven is the selective heating. Different from the conventional oven, where the heating is not selective, the heating by microwave depends on the chemical nature of the matter. Many Students of Chemistry have no knowledge of the principles involved in this selective heating, in spite of the daily microwave oven use. The heating by microwave is feasible for chemistry courses. In discussions about the microwave absorption by the matter it is possible to explore chemical properties like: heat capacity, chemical bound, molecular structure, dipole moments, polarization and dielectric constant. This paper presents the basic principles involved in the microwave heating. It is proposed a simple and inexpensive experiment that could be developed in general chemistry courses, to illustrate the relationship between heating and the chemical properties of some solvents. Experiments to check the power of the microwave oven are also proposed.
Resumo:
Immunoassay techniques provide simple, powerful and inexpensive methods for analysis of environmental contaminants. However, the acceptance of immunoassays is dependent on the clear demonstration of quality and validity compared to more traditional techniques. In this review, primarily, the understanding and the fundamentals of immunoassay methods are given in order to make good use of immunoassays, especially of EIA tests. Special attention is given to the concepts related to the enzyme-linked immunosorbent assay (ELISA) formats, such as inhibition concentration at 50% (IC50), detection limit (LOD), cross-reactivity (CR %). It is also explained why some immunoassays are quantitative methods whereas others can only be used as screening methods. A list of main commercial kits for detection of priority pollutants is given in order to help analysts. Others formats, such as flow-injection immunoassay analysis (FIIA), immunoassay chromatography and immunosensors are also cited.
Resumo:
Medicines are essential instruments to the preservation, maintenance and promotion of Health. The access to the medicine represents an important factor of social inclusion, depending on the availability of the pharmaceutical - active principle contained in the medicine that in 85% of the cases has a synthetic origin. In this scenario the importance of knowing how to make pharmaceuticals and medicines plays a significant role for the viability of the autonomous Health politics necessary for the demands of the major Nations. In this context, this work describes concisely the main aspects involved in the interdisciplinary drug discovery process, identifying the possible gorges for the successful development of innovative drugs in Brazil.
Resumo:
The goal of this work was to establish the origins of the chemical engineering course at the National School of Chemistry of the University of Brazil (at present, the School of Chemistry of the Federal University of Rio de Janeiro). There was a previous Industrial Chemistry course at the Higher School of Agriculture and Veterinary, established in 1920, following the French model. This course was the basis of the creation of the National School of Chemistry in 1933. During the 1940s, teachers and students claimed for a new course in true connection with the needs of the country and to reach full valorization of their job. The structure of the new Chemical Engineering course was approved in 1946 and the first class begun in 1952. This course was of great importance during the Brazilian industrial development during the 1950s and 1960s.
Resumo:
There has been a considerable interest in coordination complexes of molecular nitrogen (N2), partly due to a possible relationship between such complexes and the nitrogen activation process in nature. The present paper describes the synthesis and infrared spectroscopic characterization of an iron-nitrogen derivative with ethylenediamine-N,N,N',N'-tetraacetate (edta) as an experiment for an undergraduate course. The topics covered here include synthesis, reactivity and spectroscopy.