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Recently, the application of copper oxide nanoparticles (CuO-NPs) has increased considerably, primarily in scientific and industrial fields. However, studies to assess their health risks and environmental impacts are scarce. Therefore, the present study aims to evaluate the toxicological effects of CuO-NPs on the duckweed species Landoltia punctata, which was used as a test organism. To accomplish this, duckweed was grown under standard procedures according to ISO DIS 20079 and exposed to three different concentrations of CuO-NPs (0.1, 1.0, and 10.0 g L(-1)), with one control group (without CuO-NPs). The toxicological effects were measured based on growth rate inhibition, changes in the plant's morphology, effects on ultrastructure, and alterations in photosynthetic pigments. The morphological and ultrastructural effects were evaluated by electronic, scanning and light microscopic analysis, and CuO-NPs were characterized using transmission electron microscopy (TEM), zeta potential, and superficial area methods of analysis. This analysis was performed to evaluate nanoparticle size and form in solution and sample stability. The results showed that CuO-NPs affected morphology more significantly than growth rate. L. punctata also showed the ability to remove copper ions. However, for this plant to be representative within the trophic chain, the biomagnification of effects must be assessed.

Increased overall exposure of the Brazilian population to fluoridated water and fluoridated dentifrices has been identified as the main factor in the reduction of caries prevalence. Thus, the objective of the present study was to evaluate the distribution of caries in a group of 437 children ranging from 6 to 12 years of age, residing in a city without a water supply fluoridation system and without a preventive dentistry program, with the aim of orienting future health measures towards improved cost-effectiveness. Clinical examination was performed on all the children, focusing on the indices defs (decayed, extracted, and filled primary dentition surfaces) and DMFS (decayed, missing, and filled permanent dentition surfaces), representing the number of dental surfaces that were either decayed, missing or with extraction indicated, or restored. Analysis of accumulated disease frequency in relation to the population showed that 37% of the children presented 70% of all the tooth disease, with a mean defs + DMFS of 28.6. This distribution demonstrates the phenomenon of polarization, in which most of the disease and treatment needs are concentrated in a small portion of the population.

The effects of the heavy metals copper (Cu) and lead (Pb) on Sargassum cymosum were evaluated by determining uptake capacity, growth rates, photosynthetic efficiency, contents of photosynthetic pigments and phenolic compounds, 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity, and morphological and cellular changes. S. cymosum was cultivated with Cu and Pb separately and combined at concentrations of 10, 25, and 50 μM for 7 days in laboratory-controlled conditions. Seaweeds under Cu treatment showed the highest biosorption capacity, and growth rates were significantly reduced compared to the control. The photosynthesis/irradiance curves showed alterations in kinetic patterns in the metal-treated samples. Specifically, Cu treatment alone inhibited electron transport rate (ETR) response, while Pb alone induced it. However, samples treated with both Cu and Pb (Cu + Pb) showed inhibition in ETR. The total amount of pigments increased relative to control. Light microscopy showed an increase in phenolic compounds, with physodes migrating towards cortical cells. Scanning electronic microscopy revealed alterations in the typical rough surface of thallus, when compared with control, especially for Pb treatments. Based on these results, it could be concluded that Cu and Pb are stress factors for S. cymosum, promoting alterations in seaweed metabolism and stimulating protective mechanisms against oxidative stress. However, the high bioaccumulation capacity of both heavy metals indicates a possible application for S. cymosum as a biosorbent agent for contaminated wastewater when metals are in low concentrations.

Background:  Animal studies have suggested that home bleaching agents can cause morphological alterations and changes in the proliferative rate of oral epithelium. Methods:  A bleaching agent containing 10% carbamide peroxide with carbopol was used in 11 women (five smokers and six non‐smokers) during a 5‐week period. Two biopsies were performed, one of them 15 days before the beginning of the home bleaching treatment and the other immediately after the 5‐week bleaching treatment. Two analyses were performed in the histological sections obtained from the biopsies: epithelium morphometry and assessment of the epithelium's proliferative activity by proliferating cell nuclear antigen (PCNA) immunohistochemistry. Results:  The home bleaching agent increases epithelium thickness and the PCNA index in both smoker and non‐smoker patients. Conclusion:  Carbamide peroxide (10%) caused an augmentation in the proliferative activity within the basal and parabasal layers of the gingival epithelium, resulting in a change in this tissue's morphometry.

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The nutritional composition and productivity of halophytes is strongly related to the biotic/abiotic stress to which these extremophile salt tolerant plants are subjected during their cultivation cycle. In this study, two commercial halophyte species (Inula crithmoides and Mesembryanthemum nodiflorum) were cultivated at six levels of salinity using a soilless cultivation system. In this way, it was possible to understand the response mechanisms of these halophytes to salt stress. The relative productivity decreased from the salinities of 110 and 200 mmol L−1 upwards for I. crithmoides and M. nodiflorum, respectively. Nonetheless, the nutritional profile for human consumption remained balanced. In general, I. crithmoides vitamin (B1 and B6) contents were significantly higher than those of M. nodiflorum. For both species, β-carotene and lutein were induced by salinity, possibly as a response to oxidative stress. Phenolic compounds were more abundant in plants cultivated at lower salinities, while the antioxidant activity increased as a response to salt stress. Sensory characteristics were evaluated by a panel of culinary chefs showing a preference for plants grown at the salt concentration of 350 mmol L−1. In summary, salinity stress was effective in boosting important nutritional components in these species, and the soilless system promotes the sustainable and safe production of halophyte plants for human consumption.