Insights on Molecular Characteristics of Hydrochars by 13C-NMR and Off-Line TMAH-GC/MS and Assessment of Their Potential Use as Plant Growth Promoters

Hydrochar is a carbon-based material that can be used as soil amendment. Since the physical-chemical properties of hydrochar are mainly assigned to process parameters, we aimed at evaluating the organic fraction of different hydrochars through 13C-NMR and off-line TMAH-GC/MS. Four hydrochars produced with sugarcane bagasse, vinasse and sulfuric or phosphoric acids were analyzed to elucidate the main molecular features. Germination and initial growth of maize seedlings were assessed using hydrochar water-soluble fraction to evaluate their potential use as growth promoters. The hydrochars prepared with phosphoric acid showed larger amounts of bioavailable lignin-derived structures. Although no differences were shown about the percentage of maize seeds germination, the hydrochar produced with phosphoric acid promoted a better seedling growth. For this sample, the greatest relative percentage of benzene derivatives and phenolic compounds were associated to hormone-like effects, responsible for stimulating shoot and root elongation. The reactions parameters proved to be determinant for the organic composition of hydrochar, exerting a strict influence on molecular features and plant growth response

Prevalência de pectus carinatum e pectus excavatum em escolares de Manaus Prevalence of pectus carinatum and pectus excavatum in students in the city of Manaus, Brazil

OBJETIVO: Determinar a prevalência das deformidades congênitas da parede torácica anterior em escolares de 11 a 14 anos. MÉTODOS: Participaram do estudo escolares da rede estadual de ensino da cidade de Manaus (AM). Para a composição de uma amostra estatisticamente significativa, com precisão de 1% e IC95%, foram incluídos 1.332 escolares. A deformidade pectus foi identificada através de exame físico do tórax, e os indivíduos com esta deformidade responderam a um questionário com questões sobre hereditariedade e sintomatologia decorrente da anomalia torácica. RESULTADOS: A idade média dos participantes foi de 11,7 anos. A prevalência da deformidade pectus foi de 1,95% (pectus excavatum: 1,275%; pectus carinatum: 0,675%). Dos 26 escolares com deformidades pectus, 17 (65,4%) tinham pectus excavatum, e 18 (69,2%) eram do sexo masculino. Houve associação com a escoliose em 3 casos (11,5%). História familiar de pectus foi relatada por 17 escolares (65,4%), e 17 (65,4%) relataram dor torácica, dispneia ou palpitações. CONCLUSÕES: A prevalência das deformidades pectus encontrada neste estudo (1,95%) foi inferior àquela de trabalhos em outras regiões do país (3,6-4,9%), porém, superior àquela relatada na literatura (média, 1%).<br>OBJECTIVE: To determine the prevalence of congenital anterior chest wall deformities in 11- to 14-year-old students. METHODS: Students participating in the study were recruited from public schools in the city of Manaus, Brazil. The statistically significant sample (precision, 1%; 95% CI) comprised 1,332 students. Pectus deformities were identified by physical examination of the chest, and the individuals with one of these deformities completed a questionnaire regarding heredity and symptoms resulting from the chest abnormality. RESULTS: The mean age of the participants was 11.7 years. The prevalence of pectus abnormalities was 1.95% (pectus excavatum: 1.275%; pectus carinatum: 0.675%). Of the 26 students with a pectus deformity, 17 (65.4%) had pectus excavatum, and 18 (69.2%) were male. Concomitant scoliosis was observed in 3 cases (11.5%). A family history of pectus was reported by 17 students (65.4%), and 17 (65.4%) reported chest pain, dyspnea or palpitations. CONCLUSIONS: In this study, the prevalence of pectus deformities (1.95%) was lower than that reported in other studies conducted in Brazil (3.6-4.9%) but was higher than that reported in the literature (mean, 1%)