Utilização de um eletrodo de grafite-epóxi recoberto com [Zn(FEN)3][tetratris(4-clorofenil) borato]2 sensível a zinco(II) em meio 1,10-fenantrolina como eletrodo indicador em titulações potenciométricas de precipitação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sistema TS-FF-AAS com chama acetileno-ar como alternativa em relação à chama acetileno-óxido nitroso em FAAS na determinação de estanho

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Método simplificado para manutenção da concentração sangüínea de propofol em nível aproximadamente constante, associado ao óxido nitroso no paciente pediátrico

JUSTIFICATIVA E OBJETIVOS: A manutenção de concentração sangüínea alvo-controlada em níveis aproximadamente constantes do propofol é uma técnica que pode ser empregada de modo simplificado na sala de cirurgia. A finalidade desta pesquisa é comparar clínica e laboratorialmente a infusão de propofol em crianças usando os atributos farmacocinéticos de Short e de Marsh. MÉTODO: Foram estudados 41 pacientes com a idade de 4 a 12 anos, de ambos os sexos, estado físico ASA I ou II, distribuídos em dois grupos S (20 pacientes) e M (21 pacientes). No Grupo S utilizaram-se os atributos farmacocinéticos de Short, e no Grupo M, os atributos farmacocinéticos de Marsh. A indução anestésica foi feita com bolus de alfentanil 30 µg.kg-1, propofol 3 mg.kg-1 e pancurônio, 0,08 mg.kg-1 por via venosa. Procedeu-se a intubação traqueal e a manutenção com N2O/O2 (60%) em ventilação controlada mecânica. No grupo S a infusão de propofol foi de 254 (30 min) seguido de 216 µg.kg-1.min-1 por mais 30 min. No grupo M a infusão de propofol foi de 208 (30 min) seguido de 170 µg.kg-1.min-1 por mais 30 min. Através do atributo farmacocinético específico a cada grupo a meta foi a obtenção da concentração-alvo de 4 µg.kg-1 de propofol. Foram colhidas três amostras sangüíneas (aos 20, 40 e 60 minutos) para a dosagem do propofol pelo método da Cromatografia Líquida de Alta Performance. RESULTADOS: Os Grupos S e M foram considerados similares quanto à idade, altura, peso e sexo (p > 0,05). Não houve diferença estatística significativa entre os dois grupos estudados para os parâmetros: PAS, PAD, FC, FiN2O, SpO2 da hemoglobina e P ET CO2 no final da expiração. A comparação entre grupos no número de bolus repetidos de alfentanil não foi estatisticamente significativa. O índice bispectral (BIS) não apresentou diferença estatisticamente significativa entre M0 (vigília) e os demais momentos em ambos os grupos. Os valores Medianos da Performance do Erro (MPE) e os valores Medianos Absolutos da Performance do Erro (MAPE) mostraram diferenças estatísticas significativas entre os grupos no momento 60. Valores medianos da concentração sangüínea de propofol (µg.kg-1) mostraram diferenças estatísticas significativas entre M e S no momento 60 e entre os momentos 40 e 60 no grupo S. CONCLUSÕES: A anestesia com propofol usando os atributos farmacocinéticos de Marsh (Grupo M) apresentou menor erro no cálculo da concentração-alvo de propofol de 4 µg.kg-1. Além disso, utiliza menor quantidade de propofol para obter resultados clínicos semelhantes. Por todas essas qualidades deve ser a preferida para uso em crianças ASA I e com idades entre 4 e 12 anos.

Óxido nítrico: revisão

O óxido nítrico é um mediador gasoso responsável por uma variedade de fenômenos fisiológicos. A l-arginina é a precursora da síntese do óxido nítrico, na presença de óxido nítrico-sintase. Este artigo revê as funções das óxido nítrico-sintases e como o óxido nítrico atua na permeabilidade vascular e na síndrome de isquemia e reperfusão, assim como possíveis métodos para sua mensuração.

Determinação de zinco da sola do casco de bovinos leiteiros com ou sem lesões podais, suplementados ou não com levedura seca de cana-de-açúcar

Com o objetivo de estudar as concentrações de zinco da sola do casco de bovinos com e sem lesões podais, suplementados ou não com levedura seca, foram selecionadas e examinadas 60 vacas, escolhidas aleatoriamente, de um rebanho de 150 animais. Formaram-se quatro grupos de 15 animais, sendo o primeiro com animais com lesões podais e suplementados com levedura, o segundo com animais com lesões podais e sem suplementação de levedura, o terceiro com animais sem lesões podais e suplementados com levedura e o quarto com animais sem lesões podais e sem a suplementação de levedura. As concentrações de zinco da sola do casco foram determinadas por espectrometria de absorção atômica com chama (AAS). A comparação estatística das concentrações de zinco nas amostras foram submetidos à análise de variância, seguida pelo teste de Tukey, para comparação de médias. As médias das concentrações de zinco da sola do casco dos animais dos quatro grupos, quando comparadas estatisticamente, apresentaram diferença estatística significativa, somente nos animais com lesões podais e suplementados com levedura.

Teores de cobre, ferro, manganês e zinco no fígado e pâncreas de caprinos semi-confinados e confinados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Doses de zinco em diferentes condições de acidez de um solo de cerrado. II. Nível crítico na planta

In this work it was demanded to verify the zinc critical levels in soybean plants cultivated in a Dark-Red Latosol. So the experiment was carried out in vases with 4 liters of soil, which has received five doses of Zn (0, 1.0, 2.0, 3.0 and 4.0 ppm) in three correction levels. It was verified that the critical levels of the nutrient in plant (for 90% from highest production) was between 36 and 53 ppm to the dry matter yield and grains in treatments with correction.

Seleção de extratores químicos para avaliação da disponibilidade de zinco em solos do estado de São Paulo

The purpose of this study was to evaluate methods for predicting availability of Zn in soils. Surface soil samples representing Podzolized soils from Lins and Marilia var. Marilia and var. Lins, medium texture Dark-Red Latosol, Dusky-Red Latosol and Terra Roxa Estruturada, were gathered from fields in Jaboticabal, SP, Brazil. Com was used as indicator plant in a greenhouse experiment. Availability of Zn was determined with: 0.5 M CaCl2, 2.0 N MgCl2, N CH3COONH4 (pH 6.0 and 4.8), 0.05 and 0.1 N HCl, 0.05 N H2SO4, 0.005 M DTPA (pH 7.3 and 6.0), 1.0% Na2-EDTA, 0.01 M EDTA + 1.0 M (NH4)2CO3 (pH 8.6) and 0.02 M EDTA + 0.5 M CH3COOH + 0.5 M CH3COONH4. By using the simple correlation coefficients (Zn extracted from soils x absorbed by plants it can be concluded that the complexant agents and acid solutions showed to be efficient. The salt solutions showed low extraction capacity, low correlation coefficients and less accuracy. By considering aspects as accuracy and easy management DTPA pH 7,3 and Na2-EDTA can be indicated as the most apropriates (r values, respectively, 0.873** and 0.868** and V.C. 7.52% and 7.98%).

Histological evaluation of the response of apical tissues to glass ionomer and zinc oxide eugenol based sealers in dog teeth after root canal treatment

The object of the study was to compare two commercial root canal sealers: Ketac-Endo (a glass ionomer cement) and Fill Canal (a zinc oxide-eugenol cement). A total of 34 root canals from dog premolars with vital pulps were used. After instrumentation, the root canals were sealed with Ketac-Endo and Fill Canal cements using gutta-percha and a lateral condensation technique. After 270 days the animals were sacrificed with an anesthetic overdose and the maxillae and mandibles were removed and fixed in formalin for 48 h. After routine histological processing the sections were stained with hematoxylin-eosin and Mallory trichrome stains. Microscopic analysis revealed that Ketac-Endo cement presented better results than Fill Canal cement.

Biodisponibilidade de fontes orgânicas e inorgânicas de zinco em ovinos

This research was done to compare the effects of different zinc sources and doses in the Santa Ines sheep diet. Forty lambs at weaning, with 18,4kg BW were randomly allotted and fed 10 treatments: 1- base diet without zinc supplementation; 2- base diet + 200mg Zn/kg of DM as zinc oxide; 3- base diet + 400mg Zn/kg of DM as zinc oxide; 4- base diet + 600mg Zn/kg of DM as zinc oxide; 5- base diet + 200mg Zn/kg of DM as amino acid zinc; 6- base diet + 400mg Zn/kg of DM as amino acid zinc; 7- base diet + 600mg Zn/kg of DM as amino acid zinc; 8- base diet + 200mg Zn/kg of DM as proteinato zinc; 9- base diet + 400mg Zn/kg of DM as proteinato zinc; 10- base diet + 600mg Zn/kg of DM as proteinato zinc. The animals were weighed and sampled for blood zinc analysis, phosphatase alkaline analysis and immunoglobulins G and M analysis. At the end of the experiment liver samples were collected to study the zinc hepatic levels. There was no difference in phosphatase alkaline levels, hepatic zinc levels and weight gain (P>0,05) but differences (P<0,05) in plasmatic zinc levels and in IgG and IgM levels were observed. Based on liver tissue uptake, estimates of the zinc bioavailability, through the regression equations showed that the organic and inorganic sources of zinc did not differ.

Microbial leakage of MTA, Portland cement, Sealapex and zinc oxide-eugenol as root-end filling materials

Objective: The aim of this study was to compare the microbial leakage of mineral trioxide aggregate (MTA), Portland cement (PC), Sealapex and zinc oxide-eugenol (ZOE) as root-end filling materials.Study design: An in vitro microbial leakage test (MLT) with a split chamber was used in this study. A mixture of facultative bacteria and one yeast (S. aureus + E. faecalis + P. aeruginosa + B. subtilis + C. albicans) was placed in the upper chamber and it could only reach the lower chamber containing Brain Heart Infusion broth by way of leakage through the root-end filling. Microbial leakage was observed daily for 60 days. Sixty maxillary anterior human teeth were randomly assigned to different groups - MTA and PC (gray and white), Sealapex + zinc oxide and ZOE, control groups and subgroups to evaluate the influence of EDTA for smear layer removal. These materials were further evaluated by an agar diffusion test (ADT) to verify their antimicrobial efficacy. Data were analyzed statistically by Kruskal-Wallis and Mann-Whitney test.Results: In the MLT, Sealapex + zinc oxide and ZOE did not show evidence of microbial leakage over the 60-day experimental period. The other materials showed leakage from the 15th day. The presence of smear layer influenced microbial leakage. Microbial inhibition zones were not observed in all samples tested by ADT.Conclusion: Sealapex + zinc oxide and ZOE did not show microbial leakage over the experimental period, whereas it was verified within 15 to 45 days in MTA and Portland cement.

Estudo de dosagem de tijolos de solo-cimento com adição de resíduos de construção e demolição

An evaluation of the composition of soil cement bricks with construction and demolition waste. Sustainable development requires the existence of a production network that includes the reuse of construction waste for new materials. Current analysis investigates an optimal soil-cement composition made up of construction and demolition waste for the manufacture of pressed bricks. Soil-cement bricks were manufactured from construction and demolition wastes (CDW), A-4 classified fine sandy soil and cement CP II Z 32. Laboratory tests, comprising test compaction, optimum water content and maximum dry specific weight, consistency limits, grain size distribution and linear shrinkage, were made to characterize the materials researched. Compressive strength and absorption tests were also undertaken in different combinations of composition. Results showed that the application of CDW improved soil-cement qualities and reduced shrinkage of the material used.

ESTUDO DO ZINCO PLASMATICO E HEMATICO NA DESNUTRICAO PROTEICO CALORICA EXPERIMENTAL

Plasma and red cell zinc was assayed by atomic absorption spectrophotometry in three groups of male rats, 58 days old, weaned in the 30th day of life. Control group (20 rats) was fed with normal lab diet while the kwashiorkor group (20 rats) received a protein-free diet and the marasmic group (15 rats) received a protein calorie deficient diet. The clinical and biochemical data obtained in the different groups agreed with the nutritional state. A lower and similar concentration of Zinc in plasma and red cells was observed among both malnourished groups. In this paper the authors discuss the results and present a review of the literature concerning the role of zinc in nutrition.

Alterações histológicas de glândulas submandibulares e testículos induzidas por dietas à base de soja e dieta zinco deficiente em ratos.

The purpose of this study was to examine in rats the histologic alterations of the submandibular glands and testicles induced by soy diets and zinc deficient diet. The zinc deficiency produced testicles alterations including seminiferous tubulus atrophy, germinative epithelium degeneration, spermatogenesis alterations and a significant atrophy of the submandibular glands which presented no much delimitated acines. The soy diet without complementations also compromised the spermatogenesis by showing seminiferous tubulus atrophied and a reduction of the germinative epithelium. The soy diet complemented by saline and vitaminic mixtures didn't produced testicles alterations but its induced in the submandibular glands a hypertrophy of the ductal component mainly in relation to the granular component.