APLICAÇÃO FOLIAR DE GA3 NO CRESCIMENTO E DESENVOLVIMENTO DE Passiflora edulis Sims f. flavicarpa Degener

RESUMO Com o conhecimento de que a aplicação exógena de giberelinas pode alterar os processos fisiológicos, modificando o crescimento e o desenvolvimento das plantas, vistoque funcionam como regulador da divisão e do alongamento das células, objetivou-se com estetrabalho avaliar o crescimento e o desenvolvimento de Passiflora edulis Sims f. flavicarpa Degener cultivadosob luminosidade de 650 µmol m-2 s-1, por nove meses, e submetido a pulverizações semanais com GA3. Odelineamento experimental foi inteiramente casualizado, com cinco tratamentos (0,0; 1,5; 3,0; 15,0 e 30,0 mgL-1 de GA3) e dez repetições. O substrato utilizado foi constituído por uma mistura (1:1:1, em volume) de areia grossa lavada, moinha de carvão lavado e Latossolo Vermelho distroférrico disposto em vasos com capacidadepara 5L. As concentrações de GA3 influenciaram (p<0,05) na maioria das variáveis analisadas, com exceção do comprimento do caule principal até a inserção do primeiro caule lateral, do número de cauleslaterais, do número de nós do caule principal até à inserção do primeiro caule lateral, do número de nós do caule principal até a inserção da primeira gavinha e da primeira folha trilobada, do início da floração, donúmero de caules laterais emitidos pela planta no início da floração e do número de nós da base do caule principal até à inserção do primeiro botão floral. Concentração em torno de 15 mg L-1 propiciou maior comprimento da planta, maior número de nós da planta e maior massa fresca e seca das plantas. A utilização de 30 mg L d-1e GA3 antecipou a emissão da primeira gavinha e da primeira folha trilobada, e produziu maior número de botões florais. A utilização exógena de GA3 em concentrações de até 30 mg L-1 foi mais eficaz na indução do que na evocação floral dePassiflora edulis Sims f. flavicarpa Degener.

Determinación de la glucosa salival en adultos sanos

Objetivos: Determinar la concentración de glucosa salival de individuos sanos y compararla con la glicemia capilar. Diseño del estudio: Se realizó una recolección de saliva total en reposo, en 63 individuos no diabéticos. Se midió la concentración de glucosa salival y sanguinea capilar en todos los individuos. La glucosa salival fue determinada por método enzimático y espectrofotometría. Los datos fueron analizados usando el test de correlación de Spearman, considerando significativos valores de p<0,05. Resultados: Del total de la muestra, 47,6% eran varones y 52,4% mujeres, con una media de edad de 37,5±15,7 años. Las medias del flujo salival en reposo fueron de 0,41±0,2l ml/min en el género masculino y de 0,31±0,15 ml/min en el género femenino. No hubo diferencia significativa (p=0,07S). La media de glucosa sanguínea entre los varones fue de l00,05± 13,51 mg/dL y de 99 ,5± 13,9 mg/dL en las mujeres. La media de glucosa salival en el total de la muestra fue de 5,97±1 ,87 mg/dL, siendo 5,91±2, 19m9/dL en los varones y 5,97±1 ,56mg/dL en las mujeres, sin presentarse diferencias significativas (p=0,908). La concentración de la glucosa salival no presentó correlación estadísticamente significativa con la glicemia capilar (p=0,732). Conclusiones: De los resultados se desprende que: la concentración de la glucosa salival no depende de la glicemia capilar; la concentración de la glucosa salival no presenta diferencias entre géneros

Determinação de elementos-traço: relatório de dois exercícios interlaboratoriais

Results of two intercomparison exercises are reported. In the first one, the participants were asked to determine Cd, Cu, Pb and Zn, at the sub mg mL-1 level, in an acidified aqueous solution. In the second one, the participants were asked to determine mercury (total) in two homogeneous biological samples, hair and fish. The exercises were considered satisfactory and few reported results were discharged (3s criteria).

A fotocatálise heterogênea e sua aplicação ambiental

This article gives some basic principles of heterogeneous photocatalysis using titanium dioxide as photocatalyst and the state of art of its applications to the abatement of aqueous and atmospheric pollutants.

Mecanismo de fotodegradação de compostos orgânicos catalisada por TiO2

Conventional technology used in the treatment of wastewater has been pointed as a major environmental problem for sustainable development, since minimization is not addressed accordingly. Advanced oxidation processes (AOP), based on the formation of hydroxyl radical (•OH), a powerful oxidant agent, have been considered to be a potential technology for the destruction of many toxic compounds. Photocatalysis using solar light, an AOP, has been studied for nearly 20 years and recently attracted great interest as a clean-up technology. However, solar detoxification processes have not yet achieved commercial success. This article presents an overview of reaction mechanisms at the surface of semiconductors used as photocatalysts (specially TiO2), when heterogeneous photocatalysis is used to remove hazardous compounds from contaminated sites.

Mycobacterium tuberculosis Infection in Young Children: Analyzing the Performance of the Diagnostic Tests

This study evaluated the performance of the Tuberculin Skin Test (TST) and Quantiferon-TB Gold in-Tube (QFT) and the possible association of factors which may modify their results in young children (0-6 years) with recent contact with an index tuberculosis case. Materials and Methods: A cross-sectional study including 135 children was conducted in Manaus, Amazonas-Brazil. The TST and QFT were performed and the tests results were analyzed in relation to the personal characteristics of the children studied and their relationship with the index case. Results: The rates of positivity were 34.8% (TST) and 26.7% (QFT), with 14.1% of indeterminations by the QFT. Concordance between tests was fair (Kappa = 0.35 P<0.001). Both the TST and QFT were associated with the intensity of exposure (Linear OR = 1.286, P = 0.005; Linear OR = 1.161, P = 0.035 respectively) with only the TST being associated with the time of exposure (Linear OR = 1.149, P = 0.009). The presence of intestinal helminths in the TST+ group was associated with negative QFT results (OR = 0.064, P = 0.049). In the TST- group lower levels of ferritin were associated with QFT+ results (Linear OR = 0.956, P = 0.036). Conclusions: Concordance between the TST and QFT was lower than expected. The factors associated with the discordant results were intestinal helminths, ferritin levels and exposure time to the index tuberculosis case. In TST+ group, helminths were associated with negative QFT results suggesting impaired cell-mediated immunity. The TST-&QFT+ group had a shorter exposure time and lower ferritin levels, suggesting that QFT is faster and ferritin may be a potential biomarker of early stages of tuberculosis infection.

Gerenciamento de resíduos químicos em laboratórios de ensino e pesquisa

The generation of chemical residues in both teaching and research laboratories is a serious problem in Brazil. In this article, a Chemical Residues Management Program is presented and discussed. The Program is centered in different hierarchic positions, but driven by minimization. A common ground for discussion and distribution of related information is also proposed as a mean to spread the program throughout Brazilian Universities.

Compostos de mercúrio. Revisão de métodos de determinação, tratamento e descarte

This review article on mercury compounds deals with the differences on toxicity of different forms of this metal, the Brazilian regulation for its disposal and the usual methods of determination. Besides that, the text gives special emphasis on the methods used for the treatment and disposal of residues containing mercury, as well as the new developments being made in this area.

Métodos de extração e/ou concentração de compostos encontrados em fluidos biológicos para posterior determinação cromatográfica

When organic compounds present in biological fluids are analysed by chromatographic methods, it is generally necessary to carry out a prior sample preparation due the high complexity of this type of sample, especially when the compounds to be determinated are found in very low concentrations. This article describes some of the principal methods for sample preparation in analyses of substances present in biological fluids. The methods include liquid-liquid extraction, solid phase extraction, supercritical fluid extraction and extraction using solid and liquid membranes. The advantages and disadvantages of these methods are discussed.

Sistema de injeção em fluxo espectrofotométrico para monitorar peróxido de hidrogênio em processo de fotodegradação por reação foto-Fenton

A flow injection spectrophotometric system was projected for monitoring hydrogen peroxide during photodegradation of organic contaminants in photo-Fenton processes (Fe2+/H2O2/UV). Sample is injected manually in a carrier stream and then receives by confluence a 0.1 mol L-1 NH4VO3 solution in 0.5 mol L-1 H2SO4 medium. The product formed shows absorption at 446 nm which is recorded as a peak with height proportional to H2O2 concentration. The performance of the proposed system was evaluated by monitoring the consumption of H2O2 during the photodegradation of dichloroacetic acid solution by foto-Fenton reaction.

Emprego da amostragem de suspensão na determinação de Cu e Zn em lapa antártica e Ni em sedimento de rio por espectrometria de absorção atômica com chama

In order to demonstrate the feasibility of slurry sampling for environmental studies, different methodologies were developed for Cu and Zn in antarctic limpets and Ni in river sediment with FAAS detection. Studies focusing particle size, acid concentration, slurry stability, selectivity, among others were carried out in order to define the better conditions for slurry analysis. A study related to the depth profile for Ni in the Atibaia River sediment was made after optimization conditions for this element. For accuracy check, certified reference material was used as well as decomposition with microwave oven.

Fases estacionárias para cromatografia líquida de alta eficiência em fase reversa (CLAE-FR) baseadas em superfícies de óxidos inorgânicos funcionalizados

Particles of porous silica or other solvent resistent inorganic oxides can be functionalized by aliphatic (e.g., C-8 or C-18) or other groups to give stationary phases for use in reversed phase HPLC. The functionalization can be done by bonding of individual groups to the surface of the support particles, by producing an organic polymeric film from pre-polymers, or by adsorbing/immobilizing pre-formed polymers on the surfaces. These three types of functionalization are reviewed.

A Química Ambiental no Brasil

Defining environmental chemistry is a not an easy task because it encompasses many different topics. According to Stanley E. Manahan, author of a classical textbook of Environmental Chemistry, this branch could be defined as the one centered in the study of the sources, transport, effects and fates of chemical species in the water, soil, and air environments, as well as the influence of human activity upon these processes. More recently, new knowledge emerged from the Environmental Toxicology allowed to go even deeper in the meaning of 'effects' and 'fates' of a continuous growing number of organic and inorganic species disposed in water bodies, soils and atmosphere. Toxicity tests became an important tool to evaluate the environmental impact of such species to a great number of organisms, thus allowing to set quality criteria for drinking water, sediments and biota. The state of art shows that environmental chemistry is a multi-inter disciplinary science by nature; therefore, it needs more than a limited, unique-approach and non-oriented set of data to understand the nature of natural processes. Taking all these aspects into consideration, one can say that Environmental Chemistry in Brazil is now a well established area of research within the classical areas of the Chemistry, with a large number of emerging groups as well research groups with worldwide recognition.

Novas fases estacionárias à base de sílica para cromatografia líquida de alta eficiência

The present work reviews recent advances in the preparation of new reversed phase packing materials such as sterically protected, bidentate, hybrid organic-inorganic and monolithic phases and phases containing embedded polar groups. The bonding chemistry involved in the preparation of these phases as well as their advantages over conventional C8 and C18 reversed phases are discussed. Understanding the reasons behind the development of these newer column packings helps analysts select the best stationary phase for a given application.

O comportamento do metilmercúrio (metilHg) no ambiente

Methylmercury is the most hazardous mercury species known. Due to its high stability, lipid solubility, and ionic properties, this compound shows a high ability to cross membranes in living organisms, damaging the central nervous system, mainly the brain, and the effects of chronic poisoning are progressive. In this paper some aspects related to the toxicity and the cases of methylmercury poisoning are described. Other aspects related to the behavior of methylmercury and the environmental factors that influence the transformation of mercury in the water and sediment, with emphasis on the methylation/demethylation reactions and the mercury cycle are discussed.