Flow injection amperometric detection of ascorbic acid using a Prussian Blue film-modified electrode

The PB film-modified electrode was used as an amperometric detector for flow injection analysis of ascorbic acid. The modified electrode detector showed good sensitivity, stability and reproducibility. The calibration curve for ascorbic acid was linear over the concentration range from 5.0 x 10(-6) to 1.0 x 10(-3) mol l(-1) with a slope of 19.9 mA mol(-1) per litre and a correlation coefficient of 0.999. The detection limit of this method was 2.49 x 10(-6) mol l(-1). The relative standard deviation of six replicate injections of 2.5 x 10(-4) mol l(-1) ascorbic acid was 2.5%. The results obtained for ascorbic acid determination in pharmaceutical products are in good agreement with those obtained by using the procedure involving the reaction between triiodide and ascorbic acid. (C) 2001 Elsevier B.V. B.V. All rights reserved

A new, improved sensor for ascorbate determination at copper hexacyanoferrate modified carbon film electrodes

A new, improved sensor for the electrocatalytic determination of ascorbate has been developed that has both a low applied operating potential and a low detection limit. The sensor was constructed by depositing copper hexacyanoferrate film either electrochemically or chemically onto carbon film electrode, and it was then characterised by cyclic voltammetry and electrochemical impedance spectroscopy. Chemically deposited films were shown to be the best for ascorbate determination and were used as an amperometric sensor at +0.05 V versus SCE to determine ascorbate in wines and juice. The linear range extended to 5 mM with a limit of detection of 2.1 µM, the sensor was stable for more than four months, and it could be used continuously for at least 20 days

Prevalência de maloclusão em escolares de 5 a 12 anos de rede municipal de ensino de Araraquara

OBJETIVO: avaliar a prevalência de maloclusões em escolares na faixa etária de cinco a 12 anos, matriculadas em escolas municipais de Araraquara. MÉTODO: com base no número total de crianças (7235) realizou-se o cálculo da amostragem, envolvendo sete escolas, num total de 3380 crianças. Um estudo piloto e a calibração dos examinadores precederam o início da pesquisa. Foram excluídas 1934 crianças da amostra por não atenderem aos critérios de inclusão. Na avaliação clínica, foram analisados, as relações inter-arcos nos sentidos transversal, vertical e sagital, a relação intra-arcos, o perfil e padrão de crescimento, a presença de assimetria, além de hábitos deletérios. RESULTADOS: da amostragem total (1446), 80,29% apresentou maloclusão, sendo mais prevalente no gênero feminino (81,34%) e na faixa etária de nove a 12 anos (82,52%). A relação dentária mais prevalente foi a de Classe I (63,27%), o padrão facial mais encontrado foi o Padrão I (92,87%). As alterações oclusais inter-arcos mais encontradas foram a mordida profunda e a mordida aberta, as alterações intra-arcos predominantes foram os diastemas e as giroversões. De acordo com o Teste Qui-quadrado não houve significância entre maloclusão e as variáveis: presença de hábito, assimetria, diastemas e padrão facial. Houve diferença estatisticamente significante na prevalência das variáveis: mordida aberta, mordida profunda, diastemas e dos hábitos de sucção (dedo, chupeta, mamadeira) e onicofagia quando comparada as duas faixas etárias estudadas. CONCLUSÃO: as maloclusões acometem a maior parte das crianças nessa faixa etária, tendo origem predominantemente dentária e com pouco ou nenhum comprometimento facial, evidenciando a necessidade da intervenção precoce.PURPOSE: to evaluate the prevalence of malocclusion in school children between 5 and 12 years-old enrolled in public schools in Araraquara_S.P. (Brazil). METHOD: based on the total number of children (7235) it was carried out the calculation of sampling, involving seven schools, a total of 3380 children. A pilot study and calibration of examiners preceded the study onset. 1934 children were excluded from the sample because they didn't apply for the inclusion criteria. In clinical evaluation, there were analyzed the inter-arcs in transverse, vertical and sagittal directions, intra-arch relationship, facial profile, growth pattern, presence of asymmetry, and harmful habits. RESULTS: of the total sample (1446), 80.29% had malocclusion, being more prevalent in females (81.34%) from 9 to 12 years-old (82.52%). The most prevalent dental relationship was Class I (63.27%), Standard I was the most found facial pattern (92.87%). The predominant inter-arch malocclusions were deep bite and anterior open bite, and the most prevalent intra-arches occlusal changes were spacing and rotation. According to the Chi-square test, there was no significance between malocclusion and the variables: presence of habit, asymmetry, spacing and facial profile. There was a statistically significant difference in the prevalence of variables: open bite, deep bite, spacing, sucking habits (sucking, pacifier, bottle) and the onychophagia habit, when compared the two age groups studied. CONCLUSION: malocclusions affect the most children in this age group, with predominantly dental origin and with little or no facial involvement, obviating the need for early intervention

Physical disabilities in leprosy patients after discharge from multidrug therapy in Northern Brazil

Chronic sequelae and disabilities are one of the main problems in leprosy. The current study aimed to estimate the prevalence of disabilities in leprosy patients after successfully completing multidrug therapy in Araguaína, Tocantins State, Brazil. This was a cross-sectional study including 282 cases diagnosed from 2004 to 2009. The degrees of disability at diagnosis and at discharge from treatment were collected from medical records and the National Information System for Notifiable Diseases (SINAN). A simplified neurological workup was performed after discharge from treatment. The prevalence of disabilities at diagnosis was 29.4%, and 8.9% of then was grade II. Between diagnosis and discharge, the degree of physical disability worsened in 25% of cases. At diagnosis, the proportion of deformities was significantly higher in men (RR = 1.7; 95%CI: 1.23-2.37). There was a significant association between disability and multibacillary disease (p < 0.001) and occurrence of reactions (p < 0.001). The data show that after discharge from multidrug therapy, in order to prevent chronic sequelae and functional limitations, continuous monitoring is still needed for individuals that have been recorded as cured and thus deleted from the records

Study of the somaclonal variation produced by different methods of polyploidization in Asparagus officinalis L.

Polyploid plants have been induced in different Asparagus officinalis L. breeding programs in order to obtain plants with improved agronomical traits, such as large spear diameter or segregation ratios with a higher number of males. The polyploidization methods can produce somaclonal variation in the polyploid plants obtained and, therefore, unwanted changes in the agronomical traits of the initial elite plants. We used two different polyploidization methods to induce polyploid plants from diploid genotypes of commercial varieties and tetraploid genotypes of the Spanish landrace “Morado de Huétor”. The first method was the culture of rhizome buds in the medium ARBM-3 (Asparagus Rhizome Bud Medium), supplemented with different concentrations of colchicine (0.1–0.75 g l−1) for 10 and 20 days. The best polyploidization rate obtained was 25 % (0.5 g l−1 colchicine for 10 days). The second method was the regeneration of polyploid plants from callus culture, resulting in a polyploidization rate of 40 and 12.5 % for the diploid genotype CM077 and the tetraploid genotype HT156, respectively. Additionally, we have developed a new protocol to separate the mixoploids generated into their different genetic components, obtaining plants with a unique ploidy level. EST-SSRs markers were employed to analyze the genetic stability of polyploidy plants. Somaclonal variation was not detected for polyploidy plants obtained through the culture of rhizome bud explants. Therefore, these polyploid plants should maintain the agronomical traits of the initial elite plants. However, somaclonal variation was detected in the polyploid plants regenerated from callus culture.Fil: Regalado González, Jose Javier. Instituto de Horticultura Subtropical y Mediterránea La Mayora; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Carmona Martín, E.. Instituto de Horticultura Subtropical y Mediterránea La Mayora; EspañaFil: Castro, P.. Universidad de Córdoba; EspañaFil: Moreno, R.. Universidad de Córdoba; EspañaFil: Gil, J.. Universidad de Córdoba; EspañaFil: Encina, C. L.. Instituto de Horticultura Subtropical y Mediterránea La Mayora; Españ