269 resultados para ciclo biológico
Resumo:
O objetivo do trabalho foi determinar a duração do ciclo de produção e a necessidade térmica de seis clones de 'Concord' sobre três porta-enxertos no norte do Paraná. Foram avaliados os clones '22', '28', '49', '202', '211' e '225', obtidos pela Embrapa Uva e Vinho, e enxertados sobre os porta-enxertos 'IAC 766', 'IAC 572' e '420-A'. O trabalho foi realizado em área experimental pertencente ao Centro Tecnológico da COROL - Cooperativa Agroindustrial, localizado no município de Rolândia-PR. O experimento foi realizado em esquema fatorial (6 clones x 3 porta-enxertos), em delineamento inteiramente casualizado, com cinco repetições. As plantas foram conduzidas em sistema de latada, no espaçamento de 4,0 m x 2,0 m, e as avaliações foram realizadas nas safras de 2009/2010 e 2010/2011. Verificou-se que dentre os clones de 'Concord' avaliados, o '202' apresenta a menor duração do ciclo entre a poda e a colheita, sendo portanto o mais precoce. Dentre os porta-enxertos, o '420-A' induz a maior taxa de acúmulo diário de sólidos solúveis do mosto, proporcionando redução do ciclo total e da demanda térmica dos clones de 'Concord', enquanto o 'IAC 572' induz a menor taxa, promovendo aumento do ciclo e da demanda térmica dos clones.
Resumo:
OBJETIVO: Determinar o nível de qualidade da proteção radiológica para os pacientes durante a realização de exames radiológicos e avaliar a efetividade de uma intervenção dirigida a melhorar a qualidade. MATERIAIS E MÉTODOS: Realizou-se um ciclo de melhoria em um serviço de radiologia da Administração Geral de Saúde do Algarve, Portugal. Utilizando seis critérios de qualidade, foram efetivadas uma avaliação, uma intervenção focada nos critérios mais problemáticos (durante oito meses) e uma reavaliação. As amostras foram aleatórias (n = 60), possibilitando a inferência sobre as estimativas pontuais e intervalos de confiança do cumprimento de cada critério, assim como o cálculo da significância estatística da melhoria identificada, através do teste Z. RESULTADOS: Na avaliação inicial, todos os critérios de qualidade apresentaram falhas. Após a intervenção, a melhoria relativa mínima foi de 33% em cinco dos seis critérios, sendo significativa (p < 0,05) em dois deles. A frequência absoluta de não conformidades diminuiu de 38 (primeira avaliação) para 21 (segunda avaliação), que corresponde a uma melhoria de 44,7%. CONCLUSÃO: O início do ciclo de avaliação institucional revelou uma margem de melhoria que antes parecia incipiente, porém, a intervenção implementada foi efetiva para estimular boas práticas e aumentar o nível de proteção radiológica para os pacientes.
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The contribution of the industrial activities to the environmental contamination phenomena is evident. Great efforts are dedicated to the establishment of methodologies which permits an adequate treatment of the produced effluents, as a manner of minimizing the environmental impact of these wastes. The methodologies based on photocatalytic processes are very promise alternatives, because permits degradation of a great number of chemical substances of high toxic potential, without the use of other chemicals. The present work is an overview about the principal environmental aspects related with the paper and cellulose industry and the main alternatives employed for the reduction of environmental impact produced for its residues. The principal results of the photocatalytic treatment of this kind of effluents using metallic semiconductors is also showed.
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A model for the construction of a simple and cheap apparatus to be used as bioreactor for reactions catalyzed by baker's yeast (Saccharomyces cerevisiae) is described. The bioconversion and separation of cells from products and residual substrates are obtained at the same time. The reactions carried out in this type of reactor are faster than those catalyzed by immobilized cells. Yeast cells can be cultivated in this bioreactor operating with cell recycling at appropriated conditions using glucose and other nutrients.
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The most relevant advances on the analytical applications of glutathione determination based on glutathione redox cycle and the antioxidant system are given. The main enzymes that participate of the glutathione metabolism are the glutathione peroxidase and glutathione reductase. The glutathione peroxidase has a major role in the removal of hydrogen peroxide and lipid peroxides from the cells. These enzymes, operating in tandem with catalase and superoxide dismutase promote a scavenging of oxyradical products in tissues minimizing damages caused by these species. Reduced glutathione is the major intracellular thiol found in mammals and changes in the glutathione concentration in biological fluids or tissues may provide a useful marker in certain disorders like hemolytic anemia, myocardial oxidative stress and in the investigation of some kinds of cancers. Particular attention is devoted to the main advantages supplied by biosensors in which there is an incorporation of bioactive materials for the glutathione determination. The correlation between stability and sensitivity of some reduced glutathione electrochemical sensors is discussed.
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Synthetic methods used for the preparation of azaindoles are described in this article. Applications in the preparation of bioactive molecules are given: synthesis of substituted 6-azaindoles as benzodiazepines receptor ligands, substituted 7-azaindoles as dopamine D4 ligands and preparation of an olivacine analogue.
Resumo:
The chemotherapy agents against cancer may be classified as "cell cycle-specific" or "cell cycle-nonspecific". Nevertheless, several of them have their biological activity related to any kind of action on DNA such as: antimetabolic agents (DNA synthesis inhibition), inherently reactive agents (DNA alkylating electrophilic traps for macromolecular nucleophiles from DNA through inter-strand cross-linking - ISC - alkylation) and intercalating agents (drug-DNA interactions inherent to the binding made due to the agent penetration in to the minor groove of the double helix). The earliest and perhaps most extensively studied and most heavily employed clinical anticancer agents in use today are the DNA inter-strand cross-linking agents.
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A new solid phase microextraction (SPME) system, known as in-tube SPME, was recently developed using an open tubular fused-silica capilary column, instead of an SPME fiber, as the SPME device. On-line in-tube SPME is usually used in combination with high performance liquid chromatography. Drugs in biological samples are directly extracted and concentrated in the stationary phase of capillary columns by repeated draw/eject cycles of sample solution, and then directly transferred to the liquid chromatographic column. In-tube SPME is suitable for automation. Automated sample handling procedures not only shorten the total analysis time, but also usually provide better accuracy and precision relative to manual techniques. In-tube SPME has been demonstrated to be a very effective and highly sensitive technique to determine drugs in biological samples for various purposes such as therapeutic drug monitoring, clinical toxicology, bioavailability and pharmacokinetics.
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The chemical and microbiological decomposition of the garbage deposited in landfills leads to the generation of a dark and malodorous liquid residue that shows a chemical composition of extreme variability and complexity. When matured, the leachates show low biodegradability, which makes it difficult to treat by conventional biological processes. In this work a new strategy for the treatment of landfill leachates is proposed, involving a preliminary treatment by heterogeneous photocatalysis followed by an activated sludge system. The results demonstrate that photochemical treatments of 60 and 90 min significantly enhance the leachates' biodegradability favoring subsequent biological treatment. The biodegradability rate (BOD/COD) was also greatly enhanced.
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The generation of reactive oxygen species (ROS) may be both beneficial to cells, performing functions in intracellular signaling and detrimental, modifying cellular biomolecules. ROS can cause DNA damage, such as base damage and strand breaks. Organisms respond to chromosome insults by activation of a complex and hierarchical DNA-damage response pathway. The extent of DNA damages determines cell fate: cell cycle arrest and DNA repair or cell death. The ATM is a central protein in the response to DNA double-strand breaks by acting as a transducer protein. Collected evidences suggest that ATM is also involved in the response to oxidative DNA damage.
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Soils play an important role in the biogeochemical cycle of mercury as a sink for and source of this metallic species to atmospheric and hydrological compartments. In the study reported here, various types of soil were evaluated to ascertain the influence of parameters such as pH, organic matter content, Fe, Al, sand, silt, clay, C/H, C/N, C/O atomic ratios, and cation exchange capacity on the distribution of Hg in Amazonia's mid-Negro River basin. The data obtained were interpreted by multivariate exploratory analyses (hierarchical cluster analysis and principal component analysis), which indicated that organic matter plays an important role in mercury uptake in the various soils studied. The soils in floodable areas were found to contain 1.5 to 2.8-fold higher Hg concentrations than those in non-floodable areas. Since these soils are flooded almost year-round, they are less available to participate in redox processes at the soil/atmosphere interface. Hence, floodable areas, which comprise humic-rich soils, accumulate more mercury than non-floodable soils, thus playing an important role in the biogeochemical cycle of Hg in Amazonia's mid-Negro River basin.
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This work describes the synthesis of the glycosylated amino acids αGlcNAc-Thr, βGlcNAc-Thr and αLacNAc-Thr by the glycosylation reaction of the amino acid threonine with the corresponding glycosyl donors αGlcNAcCl and αLacN3Cl. The glycosylated amino acids containing the sugar units α-D-GlcNAc and α-D-LacNAc O-linked to threonine amino acids are related to O-glycans found in mucins of the parasite Trypanosoma cruzi, while the corresponding β-D-GlcNAc isomer is involved in cellular signaling events.
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Glutathione (GSH) and related enzymes are pivotal for the normal functioning of several important biological processes. In this review we discuss the biosynthesis and the catalytic cycles of glutathione as well as the major GSH-related enzymes. We also present how glutathione and enzymes are involved in cancer and the chromatographic and non-chromatographic methods used to analyze glutathione and/or its derivatives.
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Using a sampling method of particulate matter (PM) without the use of a dilution tunnel allows for evaluations of the volatile hydrocarbons (HC) in the emissions of diesel cycle engines. The procedure in this work applied a heated filter with temperature controlled. The volatile compounds are condensed at low temperature, allowing for evaluation of the HC by thermal desorption of the PM and for analysis of the condensed compounds of the exhaust gases.
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The ethanol extracts from leaves, stems, pods and roots were assayed against the 3rd instar Aedes aegypti larvae and the highest activity was observed in the roots extracts (LC50 47.86 ppm). This extract was submitted to partition with hexane, chloroform, ethyl acetate and methanol. The respective fractions were bioassayed and the best larvicidal activities were identified in the hexane (LC50 23.99 ppm) and chloroform (LC50 13.80 ppm) fractions. Antioxidant activity (DDPH method) was observed in the ethanol extract (IC50 276 µg/mL) from roots of T. toxicaria. Fractions from this extract were also tested and the highest antioxidant activity (IC50 89 µg/mL) was found in the methanol fraction. The flavonoids iso-obovatin (1), obovatin (2), 6a,12a-dehydro-β-toxicarol (3), 6a,12a-dehydro-α-toxicarol (4) and α-toxicarol (5) were isolated and bioassayed against A. aegypti. The flavonoid 5 showed the best larvicidal activity (LC50 24.55 ppm). The antioxidant activity of 2 was investigated and showed IC50 3.370 µg/mL. The antioxidant and larvicidal activities of Tephrosia toxicaria are reported for the first time.