The uptake, bioaccumulation, biotransformation, and risks of nanomaterials (NMs) for the food crops are still not well understood. Very few NMs and plant species have been studied, mainly at the very early growth stages of the plants. Most of the studies, except one with multiwalled carbon nanotubes performed on the model plant Arabidopsis thaliana and another with ZnO nanoparticles (NPs) on ryegrass, reported the effect of NMs on seed germination or 15 day old seedlings. Very few references describe the biotransformation of NMs in food crops and the possible transmission of the NMs to the next generation of plants exposed to NMs is unknown. The possible biomagnification of NPs in the food chain is also unknown.

With the dramatic increase in nanotechnologies, it has become increasingly likely that food crops will be exposed to excess engineered nanoparticles (NPs). In this study, cucumber plants were grown to full maturity in soil amended with either CeO2 or ZnO NPs at concentrations of 0, 400, and 800 mg/kg. Chlorophyll and gas exchange were monitored, and physiological markers were recorded. Results showed that, at the concentrations tested, neither CeO2 nor ZnO NPs impacted cucumber plant growth, gas exchange, and chlorophyll content. However, at 800 mg/kg treatment, CeO2 NPs reduced the yield by 31.6% compared to the control (p ≤ 0.07). ICP-MS results showed that the high concentration treatments resulted in the bioaccumulation of Ce and Zn in the fruit (1.27 mg of Ce and 110 mg Zn per kg dry weight). μ-XRF images exhibited Ce in the leaf vein vasculature, suggesting that Ce moves between tissues with water flow during transpiration. To the authors' knowledge, this is the first holistic study focusing on the impacts of CeO2 and ZnO NPs in the life cycle of cucumber plants.

BackgroundTo address cardiovascular disease risk factors among Hispanics, a community model of prevention requires a comprehensive approach to community engagement. The objectives of our intervention were to reduce cardiovascular disease risk factors in Hispanics living in 2 low-income areas of El Paso, Texas, and to engage the community in a physical activity and nutrition intervention.MethodsDrawing on lessons learned in phase 1 (years 2005-2008) of the HEART Project, we used an iterative, community-based process to develop an intervention based on an ecological framework. New community partners were introduced and community health workers delivered several elements of the intervention, including the curriculum entitled "Mi Corazón, Mi Comunidad" ("MiCMiC" [My Heart, My Community]). We received feedback from the project's Community Health Academy and Leadership Council throughout the development process and established a policy agenda that promotes integration of community health workers into the local and state workforce.OutcomeCollaboration with 2 new community partners, the YWCA and the Department of Parks and Recreation, were instrumental in the process of community-based participatory research. We enrolled 113 participants in the first cohort; 78% were female, and the mean age was 41 years. More than 50% reported having no health insurance coverage. Seventy-two (60%) participants attended 1 or more promotora-led Su Corazón, Su Vida sessions, and 74 (62%) participants attended 1 or more of the 15 exercise classes.InterpretationHEART phase 2 includes a multilevel ecological model to address cardiovascular disease risk among Hispanics. Future similarly targeted initiatives can benefit from an ecological approach that also embraces the promotora model.

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There is lack of information about the effects of nanoparticles (NPs) on cucumber fruit quality. This study aimed to determine possible impacts on carbohydrates, proteins, mineral nutrients, and antioxidants in the fruit of cucumber plants grown in soil treated with CeO2 and ZnO NPs at 400 and 800 mg/kg. Fourier transform infrared spectroscopy (FTIR) was used to detect changes in functional groups, while ICP-OES and μ-XRF were used to quantify and map the distribution of nutrient elements, respectively. Results showed that none of the ZnO NP concentrations affected sugars; however at 400 mg/kg, CeO2 and ZnO NPs increased starch content. Conversely, CeO2 NPs did not affect starch content but impacted nonreducing sugar content (sucrose). FTIR data showed changes in the fingerprint regions of 1106, 1083, 1153, and 1181, indicating that both NPs altered the carbohydrate pattern. ZnO NPs did not impact protein fractionation; however, CeO2 NPs at 400 mg/kg increased globulin and decreased glutelin. Both CeO2 and ZnO NPs had no impact on flavonoid content, although CeO2 NPs at 800 mg/kg significantly reduced phenolic content. ICP-OES results showed that none of the treatments reduced macronutrients in fruit. In case of micronutrients, all treatments reduced Mo concentration, and at 400 mg/kg, ZnO NPs reduced Cu accumulation. μ-XRF revealed that Cu, Mn, and Zn were mainly accumulated in cucumber seeds. To the best of the authors' knowledge this is the first report on the nutritional quality of cucumber fruit attributed to the impact of CeO2 and ZnO NPs.