6 results on '"Rocha-Santos TAP"'
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2. Sargassum muticum and Osmundea pinnatifida Enzymatic Extracts: Chemical, Structural, and Cytotoxic Characterization.
- Author
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Rodrigues D, Costa-Pinto AR, Sousa S, Vasconcelos MW, Pintado MM, Pereira L, Rocha-Santos TAP, Costa JPD, Silva AMS, Duarte AC, Gomes AMP, and Freitas AC
- Subjects
- Animals, Cell Line, Fibroblasts, Mice, Molecular Structure, Plant Extracts isolation & purification, Plant Extracts toxicity, Polysaccharides chemistry, Polysaccharides isolation & purification, Polysaccharides toxicity, Proton Magnetic Resonance Spectroscopy, Spectroscopy, Fourier Transform Infrared, Subtilisins metabolism, Toxicity Tests, Dietary Supplements, Plant Extracts chemistry, Rhodophyta chemistry, Sargassum chemistry, Seaweed chemistry
- Abstract
Seaweeds, which have been widely used for human consumption, are considered a potential source of biological compounds, where enzyme-assisted extraction can be an efficient method to obtain multifunctional extracts. Chemical characterization of Sargassum muticum and Osmundea pinnatifida extracts obtained by Alcalase and Viscozyme assisted extraction, respectively, showed an increment of macro/micro elements in comparison to the corresponding dry seaweeds, while the ratio of Na/K decreased in both extracts. Galactose, mannose, xylose, fucose, and glucuronic acid were the main monosaccharides (3.2-27.3 mg/g
lyophilized extract ) present in variable molar ratios, whereas low free amino acids content and diversity (1.4-2.7 g/100gprotein ) characterized both extracts. FTIR-ATR and 1H NMR spectra confirmed the presence of important polysaccharide structures in the extracts, namely fucoidans from S. muticum or agarans as sulfated polysaccharides from O. pinnatifida . No cytotoxicity against normal mammalian cells was observed from 0 to 4 mglyophilized extract /mL for both extracts. The comprehensive characterization of the composition and safety of these two extracts fulfils an important step towards their authorized application for nutritional and/or nutraceutical purposes., Competing Interests: The authors declare no conflict of interest.- Published
- 2019
- Full Text
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3. Oxidation of benzoic acid from biomass burning in atmospheric waters.
- Author
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Santos PSM, Cardoso HB, Rocha-Santos TAP, and Duarte AC
- Subjects
- Biomass, Hydrogen Peroxide chemistry, Hydroxyl Radical chemistry, Iron chemistry, Oxidants chemistry, Oxidation-Reduction, Benzoic Acid chemistry, Photolysis, Sunlight
- Abstract
This work evaluates the degradation of benzoic acid, a tracer from biomass burning, by different oxidation agents (Fe (III); H
2 O2 ; sunlight; and combinations of the previous ones) in model solutions and in real atmospheric waters. The extent of reactions was assessed by Ultraviolet-Visible and molecular fluorescence spectroscopies. The oxidation of benzoic acid occurred with the chemical oxidants Fe (III), H2 O2 , Fe (III) and H2 O2 simultaneously in the presence of sunlight, and with Fe (III) and H2 O2 simultaneously in the absence of light. The decrease of the pH value from neutral to acid for atmospheric waters generally increased the extent of oxidation. Sunlight was an important oxidation agent, and its combination with chemical oxidants increased the oxidation rate of benzoic acid, possibly due to the photogeneration of hydroxyl radicals. The results also suggested the occurrence of direct and indirect photolysis of benzoic acid in atmospheric waters. Moreover, the oxidation of benzoic acid produced new and more complex chromophoric compounds, which were then degraded. In addition, the nocturnal period is not sufficient for the full degradation of benzoic acid and of the intermediates formed by Fenton-like oxidation. The diurnal period may be enough for their full degradation through photo-Fenton-like oxidation, but this depends on the composition of the atmospheric waters, namely of the chromophoric content. Thus, this study highlights that benzoic acid from biomass burning, and its derivatives, may persist in atmospheric waters for periods of longer than one day, becoming available for other reactions, and may also affect the terrestrial and aquatic ecosystems through the wet depositions., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
4. Recent Progress in Biosensors for Environmental Monitoring: A Review.
- Author
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Justino CIL, Duarte AC, and Rocha-Santos TAP
- Subjects
- Environmental Monitoring, Environmental Pollutants, Humans, Nanotechnology, Pesticides, Biosensing Techniques
- Abstract
The environmental monitoring has been one of the priorities at the European and global scale due to the close relationship between the environmental pollution and the human health/socioeconomic development. In this field, the biosensors have been widely employed as cost-effective, fast, in situ, and real-time analytical techniques. The need of portable, rapid, and smart biosensing devices explains the recent development of biosensors with new transduction materials, obtained from nanotechnology, and for multiplexed pollutant detection, involving multidisciplinary experts. This review article provides an update on recent progress in biosensors for the monitoring of air, water, and soil pollutants in real conditions such as pesticides, potentially toxic elements, and small organic molecules including toxins and endocrine disrupting chemicals., Competing Interests: The authors declare no conflict of interest.
- Published
- 2017
- Full Text
- View/download PDF
5. Salinity induced effects on the growth rates and mycelia composition of basidiomycete and zygomycete fungi.
- Author
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Venâncio C, Pereira R, Freitas AC, Rocha-Santos TAP, da Costa JP, Duarte AC, and Lopes I
- Subjects
- Basidiomycota growth & development, Mycelium growth & development, Rhizopus growth & development, Salinity, Salt Tolerance drug effects, Seawater chemistry, Sodium Chloride toxicity, Basidiomycota drug effects, Mycelium drug effects, Rhizopus drug effects, Soil chemistry, Soil Microbiology standards
- Abstract
Soil salinization, as the combination of primary and secondary events, can adversely affect organisms inhabiting this compartment. In the present study, the effects of increased salinity were assessed in four species of terrestrial fungi: Lentinus sajor caju, Phanerochaete chrysosporium, Rhizopus oryzae and Trametes versicolor. The mycelial growth and biochemical composition of the four fungi were determined under three exposure scenarios: 1) exposure to serial dilutions of natural seawater (SW), 2) exposure to serial concentrations of NaCl (potential surrogate of SW); and 3) exposure to serial concentrations of NaCl after a period of pre-exposure to low levels of NaCl. The toxicity of NaCl was slightly higher than that of SW, for all fungi species: the conductivities causing 50% of growth inhibition (EC
50 ) were within 14.9 and 22.0 mScm-1 for NaCl and within 20.2 and 34.1 mScm-1 for SW. Phanerochaete chrysosporium showed to be the less sensitive species, both for NaCl and SW. Exposure to NaCl caused changes in the biochemical composition of fungi, mainly increasing the production of polysaccharides. When fungi were exposed to SW this pattern of biochemical response was not observed. Fungi pre-exposed to low levels of salinity presented higher EC50 than fungi non-pre-exposed, though 95% confidence limits overlapped, with the exception of P. chrysosporium. Pre-exposure to low levels of NaCl also induced changes in the biochemical composition of the mycelia of L. sajor caju and R. oryzae, relatively to the respective control. These results suggest that some terrestrial fungi may acquire an increased tolerance to NaCl after being pre-exposed to low levels of this salt, thus, suggesting their capacity to persist in environments that will undergo salinization. Furthermore, NaCl could be used as a protective surrogate of SW to derive safe salinity levels for soils, since it induced toxicity similar or higher than that of SW., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
- Full Text
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6. Histopathological and molecular effects of microplastics in Eisenia andrei Bouché.
- Author
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Rodriguez-Seijo A, Lourenço J, Rocha-Santos TAP, da Costa J, Duarte AC, Vala H, and Pereira R
- Subjects
- Animals, Environmental Exposure adverse effects, Oligochaeta metabolism, Plastics adverse effects, Reproduction drug effects, Gastrointestinal Tract drug effects, Immune System drug effects, Oligochaeta drug effects, Particle Size, Polyethylene adverse effects, Soil chemistry, Soil Pollutants adverse effects
- Abstract
The ocean has been assumed as the main sink of microplastics (MPs), however, soils may also receive MPs from different sources and through different pathways, which may affect the biota and their role in soil functions. To the best of our knowledge, only one study, until now, reported the effects of MPs on the survival and fitness of soil organisms (Lumbricus terrestris). In our study, epigeic earthworms, of the species E. andrei, were exposed to different concentrations of MPs (0, 62.5, 125, 250, 500 and 1000 mg/kg soil
dw ) in an OECD artificial soil and tested for reproduction, survival and growth of adults, following a standard protocol. The size of the polyethylene MPs to which earthworms were exposed ranged between 250 and 1000 μm. No significant effects were recorded on survival, number of juveniles and, in the final weight of adult earthworms after 28d of exposure, to the different concentrations of MPs. Nevertheless, FTIR-ATR of earthworms and histopathological analysis of the gut provided evidences of damages and immune system responses to MPs., (Copyright © 2016 Elsevier Ltd. All rights reserved.)- Published
- 2017
- Full Text
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