Characterization of aqueous silver nitrate solutions for leakage tests.

OBJECTIVES: To determine the pH over a period of 168 h and the ionic silver content in various concentrations and post-preparation times of aqueous silver nitrate solutions. Also, the possible effects of these factors on microleakage test in adhesive/resin restorations in primary and permanent teeth were evaluated. MATERIAL AND METHODS: A digital pHmeter was used for measuring the pH of the solutions prepared with three types of water (purified, deionized or distilled) and three brands of silver nitrate salt (Merck, Synth or Cennabras) at 0, 1, 2, 24, 48, 72, 96 and 168 h after preparation, and storage in transparent or dark bottles. Ionic silver was assayed according to the post-preparation times (2, 24, 48, 72, 96, 168 h) and concentrations (1, 5, 25, 50%) of solutions by atomic emission spectrometry. For each sample of each condition, three readings were obtained for calculating the mean value. Class V cavities were prepared with enamel margins on primary and permanent teeth and restored with the adhesive systems OptiBond FL or OptiBond SOLO Plus SE and the composite resin Filtek Z-250. After nail polish coverage, the permanent teeth were immersed in 25% or 50% AgNO3 solution and the primary teeth in 5% or 50% AgNO3 solutions for microleakage evaluation. ANOVA and the Tukey's test were used for data analyses (α=5%). RESULTS: The mean pH of the solutions ranged from neutral to alkaline (7.9±2.2 to 11.8±0.9). Mean ionic silver content differed depending on the concentration of the solution (4.75±0.5 to 293±15.3 ppm). In the microleakage test, significant difference was only observed for the adhesive system factor (p=0.000). CONCLUSIONS: Under the tested experimental conditions and based on the obtained results, it may be concluded that the aqueous AgNO3 solutions: have neutral/alkaline pH and service life of up to 168 h; the level of ionic silver is proportional to the concentration of the solution; even at 5% concentration, the solutions were capable of indicating loss of marginal seal in the composite restorations; the 3-step conventional adhesive system had better performance regarding microleakage in enamel on primary and permanent teeth.

Characterization of aqueous silver nitrate solutions for leakage tests

OBJECTIVE: To determine the pH over a period of 168 h and the ionic silver content in various concentrations and post-preparation times of aqueous silver nitrate solutions. Also, the possible effects of these factors on microleakage test in adhesive/resin restorations in primary and permanent teeth were evaluated. MATERIAL AND METHODS: A digital pHmeter was used for measuring the pH of the solutions prepared with three types of water (purified, deionized or distilled) and three brands of silver nitrate salt (Merck, Synth or Cennabras) at 0, 1, 2, 24, 48, 72, 96 and 168 h after preparation, and storage in transparent or dark bottles. Ionic silver was assayed according to the post-preparation times (2, 24, 48, 72, 96, 168 h) and concentrations (1, 5, 25, 50 percent) of solutions by atomic emission spectrometry. For each sample of each condition, three readings were obtained for calculating the mean value. Class V cavities were prepared with enamel margins on primary and permanent teeth and restored with the adhesive systems OptiBond FL or OptiBond SOLO Plus SE and the composite resin Filtek Z-250. After nail polish coverage, the permanent teeth were immersed in 25 percent or 50 percent AgNO3 solution and the primary teeth in 5 percent or 50 percent AgNO3 solutions for microleakage evaluation. ANOVA and the Tukey's test were used for data analyses (α=5 percent). RESULTS: The mean pH of the solutions ranged from neutral to alkaline (7.9±2.2 to 11.8±0.9). Mean ionic silver content differed depending on the concentration of the solution (4.75±0.5 to 293±15.3 ppm). In the microleakage test, significant difference was only observed for the adhesive system factor (p=0.000). CONCLUSIONS: Under the tested experimental conditions and based on the obtained results, it may be concluded that the aqueous AgNO3 solutions: have neutral/alkaline pH and service life of up to 168 h; the level of ionic silver is proportional to the concentration of the solution; even at 5 percent concentration, the solutions were capable of indicating loss of marginal seal in the composite restorations; the 3-step conventional adhesive system had better performance regarding microleakage in enamel on primary and permanent teeth.

Eficiência de inseticidas em tratamento de sementes de milho no controle da cigarrinha Dalbulus maidis (Hemiptera: Cicadellidae) em viveiro telado / Insecticides efficiency in treatment of corn seeds to control leafhopper Dalbulus maidis (Hemiptera: Cicadellidae) in greenhouse

O objetivo deste trabalho foi verificar a eficiência de inseticidas no tratamento de sementes no controle da cigarrinha-do-milho em viveiro telado. Sementes de milho foram tratadas ou não com inseticidas (imidacloprid, thiamethoxan, thiodicarb + zn, thiodicarb, carbofuran, carbofuran + zn e carbosulfan) e semeadas em vasos plásticos. Nas plantas, foram confinadas cigarrinhas sadias e avaliada a eficiência desses inseticidas no controle desse inseto, em diferentes intervalos de tempo e em períodos sucessivos. Os produtos imidacloprid e thiamethoxan foram os mais eficientes no controle da cigarrinha, proporcionando eficiência de controle de adultos de D. maidis igual ou superior a 70 por cento, até o trigésimo dia de avaliação, após 4 a 24h de confinamento das cigarrinhas.

This research was aimed at checking the efficiency of insecticide seed treatment on corn leafhopper control, at greenhouse. Maize seeds were treated with insecticides (imidacloprid, thiamethoxan, thiodicarb + zn, thiodicarb, carbofuran, carbofuran + zn and carbosulfan) and sowed on plastic pots. On those plants healthy leafhoppers were confined, and the efficiency of those insecticides on its control was evaluated, at different intervals of time and in successive periods. The insecticides imidacloprid and thiamethoxan were the most efficient to control the corn leafhoppers, and provided control efficiency of D. maidis adults equal or upper 70 percent until the thirtieth day of evaluation, after 4 to 24h of leafhoppers confining.

Efeito do uso contínuo de soluçäo para bochecho sobre o pH e o conteúdo mineral da placa bacteriana / Effects of the continuous use of a mouthrinsing solution on the pH and mineral content of dental plaque

Foi realizado um estudo com o objetivo de avaliar os efeitos do uso contínuo por 14 dias de uma soluçäo experimental para bochecho quanto ao pH e ao conteúdo inorgânico da placa bacteriana. Vinte e dois voluntários, alunos da FOUSP, com idade média de 19 (ñ 1,3) anos, receberam raspagem e polimento coronários, assim como orientaçöes de higiene e dieta. Em três ocasiöes, precedidas por um período de 48 horas sem higiene bucal, foram coletadas amostras de placa (3 mg) das superfícies lisas dos dentes posteriores 2 horas após o café da manhä. O pH das amostras incubadas com sacarose foi mensurado in vitro com um microeletrodo. O teor de minerais foi analisado por espectrometria de emissäo atômica. Os dados foram analisados através de testes t-pareados e de Wilcoxon. Foram observadas reduçöes significativas no pH médio de alguns minerais (P, Zn e Fe)

Determinaçao de valores referenciais de subpopulaçao linfocitaria em nossa populaçao normal / Establishing a reference range for lymphocytes subset value in our normal population

Foram processadas 62 amostras de sangue heparinizado, com a finalidade de se determinar valores de normalidade encontrados em nosso meio para a subpopulaçao linfocitaria T4 E T8, expressos em percentuais e em numeros absolutos. Estabeleceu-se tambem uma relaçao numerica entre T4/T8

Dieta em UTI, seu reflexo no tratamento, recuperaçäo e custo/dia do paciente internado / Diet in interesive care units, its reflex in the treatment, rehabilitation and cost/day of the hospitalized patient

O paciente em Terapia Intensiva é um paciente caro para o hospital. Sua alta da UTI significa a primeira vitória sobre a doença e também uma significativa reduçäo em seu custo para o hospital. O paciente de UTI, principalmente os politraumatizados e neurológicos, säo aqueles que maiores dificuldades oferecem para um apoio nutricional. Com a chegada da Alimentaçäo Parenteral Prolongada (NPP), acreditou-se que seria a soluçäo mais adequada. Entretanto têm-se observado dificuldades de ordem prática e econômica, bem como as ligadas à falta de infra-estrutura hospitalar para atender a esses pacientes, além de os resultados näo serem täo animadores como se acreditava obter. A volta à nutriçäo enteral feita com cuidado e técnica tem demonstrado ser a alternativa mais eficiente e barata em comparaçäo à NPP. Os resultados de avaliaçäo nutricional dos pacientes em nutriçäo enteral säo muito melhores e mais rápidos, sem aplicaçöes graves como no caso da NPP. A possibilidade de alta da UTI para outra unidade do hospital é mais rápida e os cuidados com o paciente säo mais simples e eficientes. Como näo poderia deixar de ser, o aparelho digestivo é o caminho fisiológico para a alimentaçäo e nutriçäo e, dessa forma, nada mais natural que o uso correto de fórmulas preparadas na cozinha dietética e ministrada através de sondas especiais. O custo de um litro de dieta para sonda enteral com todas as características necessárias é extremamente mais barato que o apoio de Nutriçäo Parenteral Prolongada