RESUMEN
BACKGROUND: Lemongrass is an aromatic plant with antioxidant and antimicrobial properties, used for the preparation of medicinal tea and for essential oil production. Previous studies have shown that extracts of lemongrass leaves contain phenolic compounds associated with health benefits. Although essential oils have been widely used as flavoring agents, there is no scientific evidence regarding the use of lemongrass essential oils in beverages. Thus, the objectives of the present study were to develop blends with lemongrass derivatives (aqueous extract, lyophilized extract, and essential oil) and lime juice for the preparation of mixed beverages, to evaluate the antioxidant and physicochemical characteristics of blends, and to determine the sensory profile and acceptance of mixed beverages. RESULTS: The formulated blends showed favorable physicochemical characteristics such as acidity and color, and they contained bioactive compounds (phenolics and vitamin C) and important antioxidant properties. Mixed beverages prepared from blends containing aqueous extract or lyophilized extract plus essential oil, which showed higher intensity of lemongrass aroma and flavor, were more readily accepted. CONCLUSION: This study demonstrates that it is possible to make suitable blends with lemongrass derivatives and lime juice for the preparation of high-quality mixed beverages with sensory pleasantness, and potentially beneficial health components. © 2018 Society of Chemical Industry.
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Antioxidantes/análisis , Bebidas/análisis , Compuestos de Calcio/análisis , Cymbopogon/química , Aditivos Alimentarios/análisis , Óxidos/análisis , Aromatizantes/análisis , Manipulación de Alimentos , Humanos , Aceites Volátiles/análisis , Fenoles/análisis , GustoRESUMEN
AIM: To investigate the relationship between diabetes mellitus and local/systemic effects of both grey and white mineral trioxide aggregate (MTA) Angelus on bone marker expression. METHODOLOGY: Wistar rats were divided into two groups: healthy and diabetic (Alloxan induced), which were further divided into three subgroups (control, GMTA Angelus and WMTA Angelus). Polyethylene tubes filled with MTA materials or empty tubes were implanted in dorsal connective tissue. On days 7 and 30, blood samples were collected for calcium, phosphorus and ALP measurement. The animals were euthanized; implanted tubes were removed and processed for immunohistochemical analysis of osteocalcin (OCN) and osteopontin (OPN). Kruskal-Wallis followed by Dunn's multiple comparison test was performed for nonparametric data, and anova followed by Tukey's test for parametric data. RESULTS: No difference in systemic serum calcium levels between both groups was observed. On day 7, serum phosphorus levels within the WMTA healthy group were higher than that of the diabetic group. On day 30, healthy rats exhibited lower phosphorus levels than diabetic ones. At both time points, the diabetic group was associated with more ALP activity than the healthy group. Immunohistochemical analyses of the healthy group revealed OCN- and OPN-positive cells in the presence of both MTA materials. However, under diabetic conditions, both OCN and OPN were absent. CONCLUSION: Both MTA materials were associated with an increase in serum calcium, phosphorus and ALP, suggesting a potential systemic effect, along with triggered differentiation of OCN- and OPN-positive cells. Moreover, in diabetic conditions, an inhibitory effect on MTA-induced differentiation of OCN- and OPN-positive cells was detected.
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Compuestos de Aluminio/análisis , Compuestos de Calcio/análisis , Diabetes Mellitus Experimental/metabolismo , Óxidos/análisis , Silicatos/análisis , Animales , Diabetes Mellitus Experimental/sangre , Combinación de Medicamentos , Inmunohistoquímica , Osteocalcina/análisis , Osteopontina/análisis , Ratas , Ratas WistarRESUMEN
Chemical solutions play important roles in endodontic treatment and promote ultrastructural changes in dentin surface. The aim of this study was to quantify root canal roughness at different concentrations of calcium hypochlorite (Ca(OCl)2) and sodium hypochlorite (NaOCl) by confocal laser scanning microscopy (CLSM). Fifty-two human mandibular premolars were sectioned and randomly organized into thirteen groups (n=8): saline (control); 1%, 2.5% and 5% NaOCl; 1%, 2.5% and 5% Ca(OCl)2; the hypochlorite groups were further divided into with or without EDTA. The chlorine concentrations of the different solutions were measured by iodine titration (%). The superficial roughness (Sa) was quantified by CLSM. Ca(OCl)2 presented substantial decrease in chlorine concentration that differed from the package indication, but without compromising the dentin ultrastructure changes. There were no significant differences in dentin roughness between Ca(OCl)2 or NaOCl at all studied concentrations. The combination with EDTA provided similar roughness values among the solutions (p>0.05). The 5% Ca(OCl)2 and NaOCl solutions significantly increased dentin roughness and did not differ from the EDTA association (p>0.05). Ca(OCl)2 promoted similar dentin roughness as the NaOCl at the same concentrations and combined with EDTA. It may be concluded that Ca(OCl)2 modified the root canal dentin roughness similarly to NaOCl, at the same concentrations and EDTA combinations used in this study. Ca(OCl)2 and NaOCl, both at 5%, significantly altered dentin roughness, overcoming EDTA association, thus Ca(OCl)2 concentrations ranging from 1% to 2.5% may be suitable solutions for root canal irrigation protocols.
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Compuestos de Calcio/farmacología , Cavidad Pulpar/efectos de los fármacos , Imagenología Tridimensional/métodos , Microscopía Confocal/métodos , Irrigantes del Conducto Radicular/farmacología , Compuestos de Calcio/análisis , Cloro/análisis , Cavidad Pulpar/ultraestructura , Dentina/efectos de los fármacos , Dentina/ultraestructura , Ácido Edético/farmacología , Humanos , Ensayo de Materiales , Distribución Aleatoria , Irrigantes del Conducto Radicular/análisis , Hipoclorito de Sodio/análisis , Hipoclorito de Sodio/farmacología , Volumetría/métodosRESUMEN
Metal contents in soil samples are commonly used to evaluate contamination levels. However, the distribution of metals is dependent on particle size. We investigated the distribution of metals in various particle size fractions of the soil from four sites of the Puchuncaví Valley (Central Chile). The soil samples were segregated into size fractions ranging from 0.3 to 20µm and analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The results of the statistical analysis of the total metal concentrations indicated that the soil samples from Greda and Maitenes, the sites nearest the industrial sources, are the most contaminated. For these sites, the size-fractionated samples containing higher concentrations of Cu, Zn, As, and Pb were found in the finer fractions, suggesting anthropogenic depositions from smelter facilities. In addition, a high Ca concentration was observed in the finer fractions, which could be attributed to the technological approaches used to reduce the SO2 emissions from the roasting process of copper sulfide. The mineral composition of fine particles permitted the identification of Tenorite and Calcium oxide, which are most likely associated with smelting activities, confirming emission of enriched particulate matter from the copper smelter.
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Monitoreo del Ambiente , Metales/análisis , Contaminantes del Suelo/análisis , Suelo/química , Compuestos de Calcio/análisis , Chile , Cobre/análisis , Óxidos/análisis , Tamaño de la Partícula , Material Particulado/análisisRESUMEN
An As-contaminated perched aquifer under an urban area affected by mining was studied over a year to determine the contamination source species and the mechanism of As mobilization. Results show that the dissolution of calcium arsenates in residues disposed on an inactive smelter has caused high levels of As pollution in the adjoining downgradient 6-km perched aquifer, reaching up to 158 mg/L of dissolved As, and releasing a total of ca. 7.5 tons of As in a year. Furthermore, free calcium ion availability was found to control As mobility in the aquifer through the diagenetic precipitation of calcium arsenates (Ca5H2(AsO4)4·cH2O) preventing further mobilization of As. Results shown here represent a model for understanding a highly underreported mechanism of retention of arsenate species likely to dominate in calcium-rich environments, such as those in calcareous sediments and soils, where the commonly reported mechanism of adsorption to iron(III) oxyhydroxides is not the dominant process.
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Arseniatos/análisis , Arsénico/análisis , Compuestos de Calcio/análisis , Contaminantes del Suelo/análisis , Adsorción , Monitoreo del Ambiente , Restauración y Remediación Ambiental , Sedimentos Geológicos/química , México , Minería , Modelos Químicos , Suelo/químicaRESUMEN
BACKGROUND: Enamel etching for brackets is usually done with phosphoric acid. Er:YAG lasers have been recently used for this purpose with conflicting results. The effects of lasers on tooth demineralization and the effects of different combinations of laser treatments and bonding agents were evaluated in this study. METHODS: The enamel contents of fluorine, calcium oxide and phosphorus pentoxide (P(2) O(5)) were analysed using acid etching, laser treatment or both. The tensile bond strength of metallic and ceramic brackets using Transbond XT and Fuji Ortho LC were also tested, using acid etching, laser treatment or a combination of both. RESULTS: All treatments reduced the contents of fluorine, P(2)O(5) and calcium oxide, and acid reduced P(2) O(5) levels more than laser. The bond strength with laser was weaker than with acid, and stronger when combining both. When using laser, the best adhesive was the Fuji Ortho LC. The combination of laser and acid produced the best results when using Transbond XT. CONCLUSIONS: The demineralization promoted by laser was lower than the one produced with acid. Laser treatment produced lower tensile stress strength than acid, but still enough to produce clinically efficient retention. The combination of laser and acid produced the best retention results.
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Recubrimiento Dental Adhesivo , Grabado Dental/métodos , Soportes Ortodóncicos , Resinas Acrílicas , Silicatos de Aluminio , Análisis de Varianza , Compuestos de Calcio/análisis , Esmalte Dental/química , Esmalte Dental/efectos de los fármacos , Esmalte Dental/efectos de la radiación , Análisis del Estrés Dental , Flúor/análisis , Humanos , Láseres de Estado Sólido , Microscopía Electrónica de Rastreo , Óxidos/análisis , Ácidos Fosfóricos , Compuestos de Fósforo/análisis , Cementos de Resina , Espectrometría por Rayos X , Estadísticas no Paramétricas , Resistencia a la TracciónRESUMEN
Inadequate abandonment of copper mine tailings under semiarid Mediterranean climate type conditions has posed important environmental risks in Chile due to wind and rain erosion. There are cost-effective technologies for tailings stabilization such as phytostabilization. However, this technology has not been used in Chile yet. This study evaluated in a greenhouse assay the efficacy of biosolids, lime, and a commercial mycorrhiza to improve adverse conditions of oxidized Cu mine tailings for adequate establishment and grow of Lolium perenne L. var nui. Chemical characterization of experimental substrates and pore water samples were performed; plant density, biomass production, chlorophyll content, and metal content in shoots was evaluated in rye grass plants after an eight-week growth period. Results showed that neutralization of tailings and superficial application of biosolids increased both aerial biomass production and chlorophyll content of rye grass. Increased Cu solubilization and translocation to shoots occurred after biosolids application (mixed), particularly on unlimed tailings, due to formation of soluble organometallic complexes with dissolved organic carbon (DOC) which can be readily absorbed by plant roots. Positive effects of mycorrhizal inoculation on rye grass growth were restricted to treatments with superficial application of biosolids, probably due to Cu toxicity effects on commercial mycorrhiza used (Glomulus intraradices).
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Compuestos de Calcio/análisis , Cobre/análisis , Lolium/metabolismo , Micorrizas/fisiología , Óxidos/análisis , Contaminantes del Suelo/metabolismo , Sulfuros/análisis , Biodegradación Ambiental , Biomasa , Chile , Conservación de los Recursos Naturales , Concentración de Iones de Hidrógeno , Residuos Industriales/economía , Lolium/crecimiento & desarrollo , Lolium/microbiología , Minería , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismo , Brotes de la Planta/microbiología , Suelo/análisis , Contaminantes del Suelo/análisis , Factores de Tiempo , Agua/análisisRESUMEN
INTRODUCTION: Composition and crystalline phases of the endodontic material mineral trioxide aggregate (MTA) is of fundamental importance for understanding its physical and chemical properties. This research was done to determine the composition of crystalline phases for ProRoot MTA. METHODS: For phase identification, powder of ProRoot MTA was analyzed by x-ray diffraction (XRD), comparing the MTA peaks with the data contained in the Powder Diffraction File of the International Centre for Diffraction Data (ICDD). To help the task of identifying a phase, chemical analysis by energy-dispersive spectrometry (EDS) and particle-induced x-ray emission (PIXE) were applied. Quantitative phase analysis was performed by applying Rietveld refinement to the XRD data. RESULTS: ProRoot MTA is composed of bismuth oxide (19.8%), tricalcium silicate (51.9%), dicalcium silicate (23.2%), calcium dialuminate (3.8%), and calcium sulfate dehydrated (1.3%). The trace elements detected were Fe, Ni, Cu, and Sr. CONCLUSIONS: Rietveld refinement was able to analyze the composition of ProRoot MTA, which is based basically on a mixture of Portland cement (with smaller quantities of calcium dialuminate and calcium sulfate dehydrated) and bismuth oxide for radiopacity.
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Compuestos de Aluminio/química , Compuestos de Calcio/química , Óxidos/química , Materiales de Obturación del Conducto Radicular/química , Silicatos/química , Bismuto/análisis , Compuestos de Calcio/análisis , Análisis Diferencial Térmico , Combinación de Medicamentos , Polvos , Silicatos/análisis , Espectrometría por Rayos X , Oligoelementos/análisis , Difracción de Rayos X/métodosRESUMEN
Bioactive glasses have been used as a graft material that can stimulate the formation of a new bone. In vitro tests usually give sensible indications about the potential bioactivity of these glasses. In the present work the influence of egg albumin on the formation of a Ca-P precipitate on a glass of the system SiO(2)-CaO-MgO-P(2)O(5) was evaluated. The samples were immersed in simulated body fluid (SBF) that simulates the composition of human plasma, with and without albumin. After immersion in this solution for 7 and 14 days, the glass was characterized by X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). AFM results of the samples after immersion in SBF with albumin show the development of a precipiate formed from the solution/substrate reaction. Glasses immersed in albumin-free SBF exhibit the formation of a thin layer easily detached from the substrate. XRD results indicate that the precipitate is essentially amorphous, evolving to octacalcium phosphate. As the formation of an adherent precipitate on the glass samples only occurred when the substrate was immersed in SBF with albumin, it is suggested that albumin improves the mineralization on the glasses.
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Materiales Biocompatibles/análisis , Fosfatos de Calcio/análisis , Vidrio/análisis , Microscopía de Fuerza Atómica , Ovalbúmina/farmacología , Animales , Materiales Biocompatibles/química , Líquidos Corporales/química , Compuestos de Calcio/análisis , Compuestos de Calcio/química , Pollos , Simulación por Computador , Vidrio/química , Óxido de Magnesio/análisis , Óxido de Magnesio/química , Ovalbúmina/análisis , Ovalbúmina/química , Ovalbúmina/ultraestructura , Óxidos/análisis , Óxidos/química , Compuestos de Fósforo/análisis , Compuestos de Fósforo/química , Plasma/química , Dióxido de Silicio/análisis , Dióxido de Silicio/química , Soluciones/química , Especificidad por Sustrato , Factores de Tiempo , Difracción de Rayos XRESUMEN
A new beamline, fully dedicated to X-ray powder diffraction (XPD) measurements, has been installed after the exit port B of the bending magnet D10 at the Brazilian Synchrotron Light Laboratory (LNLS) and commissioned. The technical characteristics of the beamline are described and some performance indicators are listed, such as the incoming photon flux and the angular/energy resolutions obtainable under typical experimental conditions. The results of a Rietveld refinement for a standard sample of Y2O3 using high-resolution data are shown. The refined parameters match those found in the literature, within experimental error. High-resolution XPD measurements on Ba2FeReO6 demonstrate a slight departure from the ideal cubic double-perovskite structure at low temperatures, not detected by previous powder diffraction experiments. The onset of the structural transition coincides with the ferrimagnetic ordering temperature, Tc approximately equal to 315 K. Subtle structural features, such as those reported here for Ba2FeReO6, as well as the determination and/or refinement of complex crystal structures in polycrystalline samples are ideal candidate problems to be investigated on this beamline.
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Compuestos de Calcio/análisis , Compuestos de Calcio/química , Óxidos/análisis , Óxidos/química , Difracción de Polvo/instrumentación , Refractometría/instrumentación , Sincrotrones/instrumentación , Titanio/análisis , Titanio/química , Difracción de Rayos X/instrumentación , Brasil , Diseño de Equipo , Análisis de Falla de Equipo , Conformación Molecular , Difracción de Polvo/métodos , Refractometría/métodos , Difracción de Rayos X/métodosRESUMEN
Tortillas are made by cooking maize in a lime solution during variable times and temperatures, steeping the grain for up to 12 h, washing and grinding it to a fine dough, and cooking portions as flat cakes for up to 6 min. The effects of the main processing steps on the chemical composition, nutritive value, and functional and physicochemical characteristics have been areas of research. The present work evaluates the effect of lime concentration (0, 1.2, 2.4, and 3.6%) and cooking times (45, 60, and 75 min) on phytic acid retention of whole maize, its endosperm, and germ, as well as on the content of calcium, iron, and zinc on the same samples. The effects of steeping time and temperature and steeping medium on the phytic acid of lime-cooked maize were also studied. Finally, phytic acid changes from raw maize to tortilla were also measured. The results indicated that lime concentration and cooking time reduce phytic acid content in whole grain (17.4%), in endosperm (45.8%), and in germ (17.0%). Statistical analyses suggested higher phytic acid loss with 1.2% lime and 75 min of cooking. Cooking with the lime solution is more effective in reducing phytic acid than cooking with water. Steeping maize in lime solution at 50 degrees C during 8 h reduced phytic acid an additional 8%. The total loss of phytic acid from maize to tortilla was 22%. Calcium content increased in whole maize, endosperm, and germ with lime concentration and cooking and steeping times. The increase was higher in the germ than in the endosperm. The level, however, can be controlled if steeping of the cooked grain is conducted in water. Iron and zinc contents were not affected by nixtamalization processing variables but were affected in steeping.
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Calcio/análisis , Manipulación de Alimentos/métodos , Hierro/análisis , Ácido Fítico/análisis , Zea mays/química , Zinc/análisis , Compuestos de Calcio/análisis , Calor , Óxidos/análisis , Semillas/química , Soluciones , Factores de TiempoRESUMEN
This study was conducted to observe the rat subcutaneous connective tissue reaction to implanted dentin tubes that were filled with mineral trioxide aggregate, Sealapex, Calciobiotic Root Canal Sealer (CRCS), Sealer 26, and the experimental material, Sealer Plus. The animals were sacrificed after 7 and 30 days, and the specimens were prepared for histological analysis after serial sections with a hard-tissue microtome. The undecalcified sections were examined with polarized light after staining according to the Von Kossa technique for calcium. At the tube openings, there were Von Kossa-positive granules that were birefringent to polarized light. Next to these granulations, there was irregular tissue, like a bridge, that was Von Kossa-positive. The dentin walls of the tubes exhibited a structure highly birefringent to polarized light, usually like a layer, in the tubules. These results were observed with all the studied materials, except the CRCS, which didn't exhibit any kind of mineralized structure. The results suggest that among the materials studied, the CRCS could have the least possibility of encouraging hard tissue deposition.
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Compuestos de Calcio/análisis , Hidróxido de Calcio/farmacología , Tejido Conectivo/efectos de los fármacos , Materiales de Obturación del Conducto Radicular/farmacología , Compuestos de Aluminio/farmacología , Animales , Birrefringencia , Bismuto/farmacología , Compuestos de Calcio/farmacología , Tejido Conectivo/química , Dentina/efectos de los fármacos , Dentina/ultraestructura , Dentina Secundaria/química , Combinación de Medicamentos , Humanos , Óxidos/farmacología , Ratas , Salicilatos/farmacología , Silicatos/farmacología , Óxido de Zinc/farmacologíaRESUMEN
The objective of this study was to investigate the antimicrobial action of mineral trioxide aggregate (MTA), Portland cement, calcium hydroxide paste (CHP), Sealapex and Dycal. The chemical elements of MTA and two Portland cements were also analyzed. Four standard bacterial strains: Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 29212), Pseudomonas aeruginosa (ATCC 27853), Bacillus subtilis (ATCC 6633), one wild fungus, Candida albicans (ICB/USP-562), and one mixture of these were used. Thirty Petri plates with 20 ml of BHI agar were inoculated with 0.1 ml of the experimental suspensions. Three cavities, each one measuring 4 mm in depth and 4 mm in diameter, were made in each agar plate using a copper coil and then completely filled with the product to be tested. The plates were pre-incubated for 1 h at environmental temperature followed by incubation at 37 degrees C for 48 h. The diameters of the zones of microbial inhibition were then measured. Samples from diffusion and inhibition halos were extracted from each plate and immersed in 7 ml BHI broth and incubated at 37 degrees C for 48 h. Analyses of chemical elements present in MTA and in two samples of Portland cement were performed with a fluorescence spectrometer Rx. The results showed that the antimicrobial activity of CHP was superior to those of MTA, Portland cement, Sealapex and Dycal, for all microorganisms tested, presenting inhibition zones of 6-9.5 mm and diffusion zones of 10-18 mm. MTA, Portland cement, and Sealapex presented only diffusion zones and among these, Sealapex produced the largest zone. Dycal did not show inhibition or diffusion zones. Portland cements contain the same chemical elements as MTA except that MTA also contains bismuth.