Metasurfaces have shown unprecedented capabilities and flexibilities for optical wave manipulation, which provide a powerful platform for the integration and minimization of multifunctional optical devices. However, the realization of the multidimensional manipulation of harmonic waves generated by nonlinear metasurfaces is still a challenge due to the lack of a theoretical guidance. Here, an efficient design strategy of nonlinear metasurfaces based on the hydrodynamic model of the free electron dynamics is demonstrated to realize the full complex‐amplitude modulation of the second harmonic generation (SHG). As a proof concept, three multifunctional nonlinear metasurfaces are designed, in which both the amplitude and the phase of the SHG waves are efficiently and independently manipulated. With numerical and experimental validations, the proposed nonlinear metasurfaces can realize the spin‐selective SHG optical vortices with independent topological charges. The design strategy of nonlinear metasurfaces shall boost the applications of nonlinear metasurfaces in optical information, optical multifunctional integration, and so on.
Elevated heart rate (HR) can be hypothesized to be involved in the pathways by which ambient air pollution, especially fine particulate matter (PM2.5), causes cardiovascular morbidity and mortality. However, evidence concerning long-term PM2.5 exposure and HR is still limited. Therefore, in this study, we assessed the associations of PM2.5 with HR levels and tachycardia prevalence and explored potential modifiers of the associations. We used baseline data of 1,802,207 adults from the Kashgar Prospective Cohort Study (KPCS). PM2.5 exposure was assessed based on satellite sensing data, meteorological factors, multi-resolution emission inventory, and measurements from ground-based surface monitors measurements. HR was measured using a calibrated electronic sphygmomanometer, and tachycardia was defined as resting heart rate (RHR) equal to or greater than 80 beats per minute. Linear regression and logistic regression models were employed to evaluate the associations of PM2.5 levels with RHR levels and tachycardia prevalence, respectively. Stratified analyses by sex, age, ethnicity, smoking status, alcohol use, and physical activity were also performed. The mean (standard deviation) age of the study participants was 39.4 (15.5) years old. In the adjusted models, an interquartile range (8.8 µg/m3) increase in PM2.5 levels was associated with 0.515 (95% confidence interval: 0.503–0.526) bpm increase in RHR levels and with 1.062-fold (95% confidence interval: 1.059–1.064) increase in the odds of tachycardia. The results were robust against several sensitivity analyses. In addition, we observed the above associations were stronger in participants that were men, of Uyghur ethnicity, smoking cigarettes, drinking alcohol, and having physical inactivity, compared to their counterparts. In summary, our findings indicate that long-term exposure to ambient PM2.5 may be hazardously associated with HR, and women, Uyghur people, and those with unhealthy lifestyles may be more vulnerable to the hazardous effects.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.