315 resultados para chelated mineral
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A irrigação por aspersão diminui bastante o risco de perda da lavoura por deficiência hídrica e aumenta a produtividade de grãos, incentivando maior uso de tecnologias como adubação mineral. Com o objetivo de avaliar o efeito de diferentes manejos da água da irrigação por aspersão com base no coeficiente de cultura (Kc) e da adubação mineral sobre a cultura do arroz cv. IAC 201, foram instalados dois experimentos em Latossolo Vermelho Distrófico, em Selvíria (MS). O delineamento foi em blocos casualizados, com quatro repetições. Os tratamentos constituíram-se de precipitação pluvial natural e três manejos de água fornecidos por aspersão. O manejo (M2) foi realizado com base no Kc do arroz de terras altas. Os manejos M1 e M3 foram definidos como 0,5 e 1,5 vezes os Kcs utilizados em M2 respectivamente. em 1995/96, utilizou-se o esquema de parcelas subdivididas, sendo as subparcelas constituídas por dois níveis de adubação: AD1 - 12 kg de N, 90 kg de P2O5 e 30 kg de K2O ha-1, e AD2 - 24 kg de N, 180 kg de P2O5 e 60 kg de K2O ha-1. A deficiência hídrica da emergência da plântula até a diferenciação do primórdio da panícula provocou aumento do ciclo e redução do porte da planta. A deficiência hídrica entre os estádios de diferenciação do primórdio da panícula e os de emborrachamento reduziu o número de espiguetas por panícula. A utilização de 1,5 vezes os valores de Kc recomendados, no manejo da irrigação por aspersão proporcionou maior produtividade de grãos. Os níveis de adubação utilizados não influenciaram a resposta da cultura ao manejo da irrigação por aspersão.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Biocompatibility in vitro tests of mineral trioxide aggregate and regular and white Portland cements
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Mineral trioxide aggregate (MTA) and Portland cement are being used in dentistry as root end-filling materials. However, biocompatibility data concerning genotoxicity and cytotoxicity are needed for complete risk assessment of these compounds. In the present study, genotoxic and cytotoxic effects of MTA and Portland cements were evaluated in vitro using the alkaline single cell gel (comet) assay and trypan blue exclusion test, respectively, on mouse lymphoma cells. The results demonstrated that the single cell gel (comet) assay failed to detect DNA damage after a treatment of cells by MTA and Portland cements for concentrations up to 1000 mu g/ml. Similarly, results showed that none of the compounds tested were cytotoxic. Taken together, these results seem to indicate that MTA and Portland cements are not genotoxins and do not induce cellular death.
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Mineral trioxide aggregate (MTA) and Portland cement are being used in dentistry as root-end-filling material for periapical surgery and for the sealing of communications between the root canal system and the surrounding tissues. However, genotoxicity tests for complete risk assessment of these compounds have not been conducted up to now. In the present study, the genotoxic effects of MTA and Portland cements were evaluated in peripheral lymphocytes from 10 volunteers by the alkaline single cell gel (comet) assay. The results pointed out that the single cell gel (comet) assay failed to detect the presence of DNA damage after a treatment of peripheral lymphocytes by MTA and Portland cements for concentrations up to 1000 mu g mL(-1). In summary, our results indicate that exposure to MTA or Portland cements may not be a factor that increases the level of DNA lesions in human peripheral lymphocytes as detected by single cell gel (comet) assay.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Durante 150 dias, 12 potras Quarto-de-Milha de 1 ano de idade permaneceram exclusivamente em pastagem de Brachiaria humidicola, num experimento inteiramente casualizado, com três tratamentos, nível 0 (recomendação do NRC, 1989); nível 50 (50% a mais do NRC); nível 100 (100% a mais do NRC), e quatro repetições. Como palatabilizante foram empregadas 270 g de açúcar. Realizaram-se biópsias na asa do osso do ílio de cada potra, no início e final do experimento, para avaliar a mobilização de Ca e a relação Ca:P. As amostras da gramínea, foram coletadas mensalmente para verificação do teor de oxalato e composição químico-bromatológica. Houve efeito de tempo na mobilização de Ca, P e da relação Ca:P (p<0,05), independentemente dos tratamentos. As médias dos três tratamentos, no início e final do período experimental foram, quanto aos teores de Ca, P e da relação Ca:P, respectivamente: 10,05, 5,22, 1,93:1 e 6,24, 4,06, 1,54:1. O teor do oxalato na gramínea variou de 1,18 a 2,00%. A utilização do nível de cálcio suplementar duas vezes superior ao recomendado pelo National Research Council não foi suficiente para impedir a mobilização deste mineral nos ossos de eqüinos pastejando Brachiaria humidicola por longos períodos.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This study aimed at evaluating the effects of trace mineral levels and sources supplemented to diets fed to semi-heavy layers in their second laying cycle on the quality of eggs stored for 14 days at different temperatures. The experimental diets consisted of the inclusion of inorganic trace minerals (T1 - control: 100% ITM) and five supplementation levels of organic trace minerals (carboaminophopho chelates) (110, 100, 90, 80, and 70% OTM). Trace mineral inclusion levels (mg/kg feed) were: T1: control - 100% ITM: Zn (54), Fe (54), Mn (72), Cu (10), I (0.61) Se (0.3); T2 - 110% OTM: Zn (59.4), Fe (59.4), Mn (79.2), Cu (11.88), I (1.21) Se (0.59); T3 - 100%: OTM: Zn (54), Fe (54), Mn (72), Cu (10.8), I (1.10) Se (0.54); T4 - 90% OTM: Zn (48.6), Fe (48.6), Mn (64.8), Cu (9.72), I (0.99) Se (0.49); T5 - 80% OTM: Zn (43.2), Fe (43.2), Mn (57.6), Cu (8.64), I (0.88), Se (0.43); T6 - 70% OTM: Zn (37.8), Fe (37.8), Mn (50.4), Cu (7.56), I (0.77) Se (0.38). A completely randomized experimental design in a split-plot arrangement with 60 treatments of four replicates each was applied. The combination of six diets versus storage temperature (room or under refrigeration) was randomized in plots, whereas the sub-plots consisted of storage times (0, 3, 7, 10, and 14 days). Data were submitted to analysis of variance of a model in slip-plots in time using the software package SAS (2000) at 5% probability level. It was concluded that 70% OTM supplementation can be used with no damage to egg quality, independently from storage temperature or time. The quality of refrigerated eggs stored up to 14 days is better than those stored at room temperature.
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This study was carried out to evaluate the effects of dietary trace mineral levels and sources on egg quality parameters of second-cycle semi-heavy layers. A number of 360 72-week-old layers were submitted to forced molting. Upon return of lay (83 weeks of age), birds were distributed according to a completely randomized experimental design of six treatments with six replicates of 10 birds each. The control treatment consisted of 0.10% dietary supplementation of trace minerals from inorganic sources, which was proportionally replaced by five levels (110, 100, 90, 80, 70%) of an organic trace mineral supplement containing 30, 30, 40, 6, 0.61, and 0.3 g/kg product of Zn, Fe, Mn, Cu, I, and Se, respectively. All diets contained equal protein, energy, and amino acid levels. Every 28 days of the experimental period (112 days) four eggs per replicate were collected for egg quality evaluation. The following parameters were evaluated: specific gravity, yolk, albumen and eggshell percentages, yolk index, Haugh units, and eggshell thickness and breaking strength. One sample per replicate, consisting of the pool of the yolks of three eggs collected at the end of each experimental period, was used to assess protein and mineral (Ca, P, Cu, Fe, Mn, and Zn) contents. The results were submitted to ANOVA, and means to the test of Tukey at 5% significance level. The evaluated trace mineral levels and sources did not influence any of the studied egg quality parameters. It was concluded that reducing organic trace mineral supplementation in up to 70% relative to 100% inorganic trace mineral supplementation does not affect egg parameters and therefore, can be applied to the diet of semi-heavy layers in their second cycle of lay.