Fitodisponibilidade de cobre, níquel e zinco em um latossolo vermelho tratado com lodo de esgoto e calagem

Contents of heavy metal on agricultural soils have been raised by land applications of sewage sludge and may constitute a hazard to plants, animals and humans. A field experiment was carried out from 1983 to 1987, to evaluate the long-term effect of sewage sludge application, with and without liming, on heavy metal accumulation and availability in a Rhodic Hapludox soil grown with maize (HMD 7974 hybrid). Trials were set up in a completely randomized blocks design with four replications. Each block was split in two bands, one with and another without liming. The sludge was applied in each band at rates: 0, 20, 40, 60 and 80 Mg ha-1 (dry basis) in a single application; and 40, 60 and 80 Mg ha-1 split in two, three and four equal yearly applications, respectively. The soil was sampled for chemical analysis each year after harvest. Soil samples were analysed for Cu, Ni and Zn in extracts obtained with DTPA and Mehlich-3 solutions, and in extracts obtained by digestion with nitric-perchloric acid (total metal contents), using an inductively coupled plasma (ICP) spectrometer. In general, Zn, Cu and Ni concentrations in DTPA and Mehlich-3 extracts increased linearly with sludge application. Total Cu and Zn concentrations increased when sludge was applied, whereas total Ni concentrations were not affected. Both extractants were suitable to evaluate Cu and Zn availability to corn in the soil treated with sewage sludge. Liming reduced the DTPA extractability of Zn. DTPA-extractable Cu concentrations were not significantly affected by liming. Mehlich-3-extractable Cu and Zn concentrations increased with liming. Only DTPA extractant indicated reduction of Ni concentrations in the soil after liming.A reciclagem agrícola do lodo de esgoto tem provocado o acúmulo de metais pesados no solo e na água, podendo atingir níveis tóxicos e causar danos às plantas cultivadas, aos animais e ao homem, por meio da cadeia trófica. Foi desenvolvido um experimento, em condições de campo entre 1983 e 1987, onde foram avaliados os efeitos da aplicação de lodo de esgoto por quatro anos, com e sem calagem, sobre a acumulação e disponibilidade de metais pesados em um Latossolo Vermelho distrófico típico cultivado com milho (HMD 7974). O delineamento utilizado foi o de blocos completos ao acaso, com quatro repetições. Cada bloco foi dividido em duas faixas nas quais foram aplicados os tratamentos com e sem calcário, e em cada faixa foi aplicado o lodo nas seguintes doses: 0, 20, 40, 60 e 80 Mg ha-1 (material seco) de lodo de esgoto, em aplicação única; e as doses de 40, 60 e 80 Mg ha-1, parceladas em dois, três e quatro anos, respectivamente. A fitodisponibilidade dos metais foi avaliada pelos extratores DTPA e Mehlich-3. Os teores extraíveis de Cu, Ni e Zn no solo aumentaram linearmente com as doses de lodo de esgoto, para os dois extratores usados. A adição de lodo de esgoto elevou os teores totais de Cu e Zn, mas não afetou os teores de Ni no solo. Os extratores DTPA e Mehlich-3 foram igualmente eficientes na predição da fitodisponibilidade de Cu e Zn. A adição de calcário reduziu a extratabilidade de Zn-DTPA, não alterou a de Cu-DTPA e aumentou os teores de Cu e Zn extraíveis do solo por Mehlich-3. Somente o extrator DTPA mostrou a redução do teor de Ni extraível do solo com a adição de calcário

Effectiveness of carbamide peroxide and sodium perborate in non-vital discolored teeth

OBJECTIVE: To evaluate the efficacy of 16% carbamide peroxide gel (CP16%), tetrahydrate sodium perborate (SP) and mixture (CP16% + SP), in walking bleaching of non-vital discolored teeth. MATERIALS AND METHODS: Sixty single-rooted human premolars with intact crowns were used and initial color was assessed using Vita shade guide and standardized photos. The teeth were stained using rabbit fresh blood for 18 days and photos of discolored teeth and color evaluation were performed. The teeth were divided into 4 groups (n= 15), according to bleaching agent used: G1) CP16% gel; G2) CP16% gel + SP; G3) SP + distilled water; G4: control. The bleaching agents were replaced twice at 7-day intervals for 21 days. All teeth were evaluated by two endodontists at days 0, 7, 14 and 21 and the color changes were assessed using Vita shade guide and standardized photos. The results were analyzed by Kruskal-Wallis and Dunn's tests (p=0.05). RESULTS: The experimental groups presented statistically similar bleaching results (p>;0.05) at the end of 7, 14 and 21 days. These groups presented significantly higher bleaching efficacy than control group (G4) (

Micromorphological and hardness analyses of human and bovine sclerotic dentin: a comparative study

The purpose of this study was to test the hypothesis that both human and bovine sclerotic dentin have similar hardness properties, in addition to similar micromorphological characteristics. Sixteen teeth (8 human and 8 bovine) exhibiting exposed dentin in the incisal edge and showing characteristics typical of sclerosis were used. Vickers surface microhardness testing was conducted. Three areas of the dentin surface of each specimen were selected. All teeth were processed for scanning electron microscopy in order to estimate the amount (in percentage) of solid dentin on the sclerotic dentin surface. The data were compared by Student's t test (α = 0.05). The micromorphological and microhardness data were compared by Pearson's linear correlation test (α = 0.05). The mean percentages of solid dentin of human and bovine sclerotic dentin were similar (human 90.71 ± 0.83 and bovine 89.08 ± 0.81, p = 0.18). The mean microhardness value (VHN) of human sclerotic dentin was significantly higher than that of bovine sclerotic dentin (human 45.26 ± 2.92 and bovine 29.93 ± 3.83, p = 0.006). No correlation was found between the microhardness values and the amount of solid dentin in the sclerotic dentin, irrespective of the species considered (human R² = 0.0240, p = 0.714; bovine R² = 0.0017, p = 0.923; and combined R² = 0.038, p = 0.46). We concluded that although both bovine and human sclerotic dentin present a similar amount of solid tissue, human sclerotic dentin presents higher microhardness than bovine sclerotic dentin.(FAPESP) São Paulo Research Foundation(CAPES) Coordination for the Improvement of Higher Education Personne

Deposição de gotas de pulverização e pH foliar no controle de plantas daninhas aquáticas

A diversidade morfológica da superfície foliar existente entre as espécies de plantas e a presença de estruturas foliares como tricomas, estômatos, cutícula e ceras podem exercer grande influência na aderência e deposição das gotas de pulverização, assim como na absorção do herbicida. Desta forma, o objetivo do presente trabalho foi estudar, em quatro espécies de plantas daninhas aquáticas (Enhydra anagallis, Eichhornia crassipes, Heteranthera reniformis e Typha subulata), a área de molhamento de gotas de pulverização nas superfícies foliares adaxial e abaxial, bem como o pH foliar. O experimento foi realizado em Botucatu-SP. As plantas foram cultivadas em caixas d'água sob condições de campo, e quando atingiram seu pleno desenvolvimento (antes do florescimento), foram realizadas as avaliações de pH foliar e da área de molhamento de gotas de pulverização. As tensões superficiais das gotas aplicadas (0,5 mL), apresentadas pelas soluções de glyphosate aplicado isolado a 5,0% v v-1 (Rodeo 480 g L-1 e.a. produto comercial), glyphosate + Aterbane BR (5,0% + 0,5% v v-1), glyphosate + Silwet L-77 (5,0% + 0,05% v v-1), além das soluções com os adjuvantes isolados, Aterbane BR (0,5% v v-1) e Silwet L-77 (0,05% v v-1) foram respectivamente 72,1; 28,7; 23,3; 37,3 e 22,1 mN m-1. As médias obtidas de pH foliar variaram entre 5,50 e 7,50, destacando-se a espécie E. anagallis com valores de 6,68 e 7,02 para as faces adaxial e abaxial, respectivamente. Dentre as plantas daninhas aquáticas avaliadas T. subulata foi a espécie que apresentou as maiores médias de área de molhamento nas faces adaxial e abaxial da folha, proporcionada pelas as soluções de glyphosate + Aterbane BR, glyphosate + Silwet L-77 e Silwet L-77, com valores de 12,99-7,03; 20,04-17,95 e 31,81-25,91 mm², respectivamente.The morphological diversity of leaf surface and structures such as trichomes, stomata, cuticle, and waxes that exists among plant species can have great influence on the adherence and deposition of spray droplets, as well as on herbicide absorption. The aim of this research was to study leaf pH and to evaluate wetting areas after applications of solution surfactants on the following aquatic weeds: Enhydra anagallis, Eichhornia crassipes, Heteranthera reniformis, and Typha subulata. The aquatic weeds were grown in reservoirs containing water under open air conditions and their leaf tissues were collected when the plants reached full development (before flowering). The mean leaf pH varied between 5.50 and 7.50; E. anagallis should be pointed out for presenting the highest pH values, of 6.68 and 7.02 on the upper and lower leaf surfaces, respectively. Surface tension reduction for glyphosate alone (5.0% v v-1), glyphosate + Aterbane BR (5.0% + 0.5% v v-1), glyphosate + Silwet L-77 (5.0% + 0.05% v v-1), and surfactants alone, Aterbane BR (0.5% v v-1), and Silwet L-77 (0.05% v v-1), were, respectively: 72.1; 28.7; 23.3; 37.3, and 22.1 mN m-1.T. subulata was the aquatic species with the highest upper and lower leaf surface wetting area

Integrated basic clinical skills: a curricular experience with early, comprehensive exposure to clinical practice

An early clinical exposure program was developed with the aim of avoiding fragmentation and stereotyped behaviors during medical training. Second-year medical students received an introductory course on Integrated Basic Clinical Skills (BCS), which included hospital rounds followed by case discussions led jointly by faculty members from medical psychology and various clinical areas (internal medicine, pediatrics, obstetrics, gynecology, and geriatrics). Special care was taken to provide a model in which medical students could learn about biological, psychological, and social aspects of illness within the same format. The article discusses the objectives, logistics, and staff of the course, based on the experience at the Federal University in São Paulo. The model offers an integrated model for both students and faculty. Further studies are necessary to evaluate these preliminary findings.Para evitar a fragmentação e a estereotipia e favorecer uma aproximação antecipada da pratica médica, foi introduzido o curso de Semiologia Integrada no programa do segundo ano do curso médico da UNIFESP. Este curso inclui a realização de anamneses no hospital, seguidas de discussões que contam com a participação conjunta dos professores de Psicologia Médica e de professores de diferentes áreas da Semiologia (Clínica Médica, Pediatria, Ginecologia, Obstetrícia e Geriatria). Foi dada atenção especial para apresentar ao estudante de Medicina um modelo que integrasse os aspectos biológicos, psicológicos e sociais do adoecer. Este artigo apresenta o projeto e as observações preliminares, que sugerem um importante potencial integrador tanto para os alunos quanto para os professores. São necessárias avaliações futuras para comprovar essas observações.Universidade Federal de São Paulo (UNIFESP)UNIFESP, EPM, São Paulo, BrazilSciEL

A structure-based site-directed mutagenesis study on the neurolysin (EC 3.4.24.16) and thimet oligopeptidase (EC 3.4.24.15) catalysis

Neurolysin (EP24.16) and thimet oligopeptidase (EP24.15) are closely related metalloendopeptidases. Site-directed mutagenesis of Tyr(613) (EP24.16) or Tyr(612) (EP24.15) to either Phe or Ala promoted a strong reduction of k(cat)/K-M for both enzymes. These data suggest the importance of both hydroxyl group and aromatic ring at this specific position during substrate hydrolysis by these peptidases. Furthermore, the EP24.15 A607G mutant showed a k(cat)/K-M of 2x10(5) M-1 s(-1) for the Abz-GFSIFRQ-EDDnp substrate, similar to that of EP24.16 (k(cat)/K-M = 3x10(5) M-1 s(-1)) which contains Gly at the corresponding position; the wild type EP24.15 has a k(cat)/K-M of 2.5x10(4) M-1 s(-1) for this substrate. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.Univ Mogi das Cruzes, CIIB, BR-08780911 Mogi Das Cruzes, SP, BrazilInst Butantan, CAT, Ctr Toxicol Aplicada, BR-05467010 São Paulo, BrazilUniv São Paulo, Inst Ciencias Biomed, Program Biol Celular, Dept Histol & Embriol, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04044020 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04044020 São Paulo, BrazilWeb of Scienc

Supramolecular Materials for Optical and Electrochemical Biosensors

It is incontestable that the interactions and bonds that keep molecules united to generate unique supramolecular compounds, with individual properties, morphologies and behaviour, are of special dynamics and singular forces. Therefore, it is necessary to discuss and consider the types of interactions that may occur in a determined system, their dynamics and number, which directly act on the energetic balance that strengthen the union between participants and give rise to a supramolecule

Bothrops jararaca Peptide with Anti-Hypertensive Action Normalizes Endothelium Dysfunction Involved in Physiopathology of Preeclampsia

Preeclampsia, a pregnancy-specific syndrome characterized by hypertension, proteinuria and edema, is a major cause of fetal and maternal morbidity and mortality especially in developing countries. Bj-PRO-10c, a proline-rich peptide isolated from Bothrops jararaca venom, has been attributed with potent anti-hypertensive effects. Recently, we have shown that Bj-PRO-10c-induced anti-hypertensive actions involved NO production in spontaneous hypertensive rats. Using in vitro studies we now show that Bj-PRO-10c was able to increase NO production in human umbilical vein endothelial cells from hypertensive pregnant women (HUVEC-PE) to levels observed in HUVEC of normotensive women. Moreover, in the presence of the peptide, eNOS expression as well as argininosuccinate synthase activity, the key rate-limiting enzyme of the citrulline-NO cycle, were enhanced. In addition, excessive superoxide production due to NO deficiency, one of the major deleterious effects of the disease, was inhibited by Bj-PRO-10c. Bj-PRO-10c induced intracellular calcium fluxes in both, HUVEC-PE and HUVEC, which, however, led to activation of eNOS expression only in HUVEC-PE. Since Bj-PRO-10c promoted biological effects in HUVEC from patients suffering from the disorder and not in normotensive pregnant women, we hypothesize that Bj-PRO-10c induces its anti-hypertensive effect in mothers with preeclampsia. Such properties may initiate the development of novel therapeutics for treating preeclampsia