52 research outputs found

    Energy Demand in Agricultural Biomass Production in Parana state, Brazil

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    Energy flow analysis is an interesting approach to assess and to improve sustainability of agricultural production systems, represented by the economy of energy resources and other inputs translated into energy terms. This type of analysis can complement the economic view contributing to more efficient production systems. Moreover, assessing crops with traditional food use may play an important role in energy provision. Energy efficiency tools were applied in order to determine the energy demand as well as the efficiency of the biomass production of several forage crops in mechanized systems conducted at Paraná state, Brazil. Material flow, input and output energy, energy balance, energy return over investment and embodied energy were used and identified that maize and sorghum were the crops that uses energy in the most efficient way, represented by the best results at net energy availability, profitability and embodied energy at the final product. Oat and ryegrass were the crops the presented the least efficient energy uses in the biomass production systems.   Keywords: Bioenergy, energy indicators, sustainability, embodied energy. &nbsp

    Structural design of contact lens-based drug delivery systems; in vitro and in vivo studies of ocular triggering mechanisms

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    This study identifies and investigates the potential use of in-eye trigger mechanisms to supplement the widely available information on release of ophthalmic drugs from contact lenses under passive release conditions. Ophthalmic dyes and surrogates have been successfully employed to investigate how these factors can be drawn together to make a successful system. The storage of a drug-containing lens in a pH lower than that of the ocular environment can be used to establish an equilibrium that favours retention of the drug in the lens prior to ocular insertion. Although release under passive conditions does not result in complete dye elution, the use of mechanical agitation techniques which mimic the eyelid blink action in conjunction with ocular tear chemistry promotes further release. In this way differentiation between passive and triggered in vitro release characteristics can be established. Investigation of the role of individual tear proteins revealed significant differences in their ability to alter the equilibrium between matrix-held and eluate-held dye or drug. These individual experiments were then investigated in vivo using ophthalmic dyes. Complete elution was found to be achievable in-eye; this demonstrated the importance of that fraction of the drug retained under passive conditions and the triggering effect of in-eye conditions on the release process. Understanding both the structure-property relationship between drug and material and in-eye trigger mechanisms, using ophthalmic dyes as a surrogate, provides the basis of knowledge necessary to design ocular drug delivery vehicles for in-eye release in a controllable manner

    Hepatic oxidative stress in an animal model of sleep apnoea: effects of different duration of exposure

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    Background: Repeated apnoea events cause intermittent hypoxia (IH), which alters the function of various systems and produces free radicals and oxidative stress. Methods: We investigated hepatic oxidative stress in adult mice subjected to intermittent hypoxia, simulating sleep apnoea. Three groups were submitted to 21 days of IH (IH-21), 35 days of IH (IH-35), or 35 days of sham IH. We assessed the oxidative damage to lipids by TBARS and to DNA by comet assay; hepatic tissue inflammation was assessed in HE-stained slides. Antioxidants were gauged by catalase, superoxide dismutase, glutathione peroxidase activity and by total glutathione. Results: After IH-21, no significant change was observed in hepatic oxidative stress. After IH-35, significant oxidative stress, lipid peroxidation, DNA damage and reduction of endogenous antioxidants were detected. Conclusions: In an animal model of sleep apnoea, intermittent hypoxia causes liver damage due to oxidative stress after 35 days, but not after 21 days

    Elaboração de manual sobre fibras alimentares e constipação intestinal

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    Objetivo: elaborar um manual com alimentos fonte de fibras para ser usado na composição da dieta líquida homogênea dos pacientes em pós-operatório no HRAC, de todas as idades, para reduzir ou prevenir a constipação intestinal. Métodos: o manual contém temática que esclarece sobre a importância das fibras alimentares, classificação, fontes, quantidades de uso, interação com outros nutrientes, forma de preparo, solubilidade, funções e problemas causados pelo excesso de ingestão. Consta também de uma lista de alimentos com quantidades de fibras presentes por 100gramas de cada alimento. Tais dados foram retirados da Tabela Brasileira de composição de Alimentos da UNICAMP e da Tabela Brasileira de Composição de Alimentos da USP. O manual foi elaborado pelas alunas do programa de Aprimoramento Profissional Fundap e será distribuído gratuitamente para todos os pacientes em pós-operatórios submetidos à dieta líquida homogênea. Além disto, o manual será disponibilizado nos sites www.centrinho.usp.br/manual e www.redeprofis.com.br. para consulta e cópias gratuitas. A arte e as ilustrações do manual foram feitas por aluno do Curso de Publicidade e Propaganda da USC. Resultados: O uso das fibras será orientado de forma preventiva para os pacientes que não apresentam constipação intestinal e de forma corretiva para os já constipados. Conclusões: A constipação intestinal é um problema de saúde pública no Brasil, principalmente entre as mulheres e tem seu quadro agravado quando estes indivíduos são submetidos a dietas líquidas e homogêneas, aonde os alimentos são liquidificados e coados e os resíduos (fibras) desprezados. Sendo assim, a composição desta dieta tem que ser enriquecida com fibras alimentares para prevenir ou corrigir a constipação intestinal

    Elaboration of handbook about dietary fibers and bowel constipation

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    Objective: to elaborate a handbook with high-fiber foods to be used in the composition of the homogeneous liquid diet for patients in postoperative period to reduce or prevent the bowel constipation. Methods: the handbook highlights the importance of dietary fibers, classification, food sources, amount of use, interaction with other nutrients, directions for preparation, solubility, functions and problems caused by the excess ingestion. It also contains a list of food with fibers quantities present in 100 grams of each food. Such data were obtained from the Tabela Brasileira de Composição de Alimentos of Unicamp and Tabela Brasileira de Composição de Alimentos of University of São Paulo. The handbook was elaborated by students from Fundap Professional Improvement Program and distributed for free for all patients of the Hospital for Rehabilitation of Craniofacial Anomalies, in postoperative period, receiving homogeneous liquid diet. The handbook was also made available in the homepages www.centrinho.usp/manual and www.redeprofis.com.br for consultation and free copies. The handbook art and illustrations were made by a student of Marketing rom USC. Results: The use of fibers will be oriented in a preventive form for patients not showing bowel constipation and in a corrective form for those already constipated. Conclusions: Bowel constipation is a public health problem in Brazil, mainly among women, and it becomes worse when individuals are submitted to a homogeneous liquid diet in which the foods are liquefied and filtered and the residues (fibers) are rejected. In such case, the composition of this diet needs to be enriched with dietary fibers to prevent or correct the bowel constipation
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