Increased fruit and vegetable consumption was associated with a modest although not statistically significant reduction in the development of major chronic disease. The benefits appeared to be primarily for cardiovascular disease and not for cancer.
Submicron aerosol particles (PM<sub>1</sub>) were measured in-situ using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer during the summer 2009 Field Intensive Study at Queens College in New York, NY. Organic aerosol (OA) and sulfate are the two dominant species, accounting for 54% and 24%, respectively, of the total PM<sub>1</sub> mass. The average mass-based size distribution of OA presents a small mode peaking at ~150 nm (<i>D</i><sub>va</sub>) and an accumulation mode (~550 nm) that is internally mixed with sulfate, nitrate, and ammonium. The diurnal cycles of both sulfate and OA peak between 01:00–02:00 p.m. EST due to photochemical production. The average (±σ) oxygen-to-carbon (O/C), hydrogen-to-carbon (H/C), and nitrogen-to-carbon (N/C) ratios of OA in NYC are 0.36 (±0.09), 1.49 (±0.08), and 0.012 (±0.005), respectively, corresponding to an average organic mass-to-carbon (OM/OC) ratio of 1.62 (±0.11). Positive matrix factorization (PMF) of the high resolution mass spectra identified two primary OA (POA) sources, traffic and cooking, and three secondary OA (SOA) components including a highly oxidized, regional low-volatility oxygenated OA (LV-OOA; O/C = 0.63), a less oxidized, semi-volatile SV-OOA (O/C = 0.38) and a unique nitrogen-enriched OA (NOA; N/C = 0.053) characterized with prominent C<sub>x</sub>H<sub>2x + 2</sub>N<sup>+</sup> peaks likely from amino compounds. Our results indicate that cooking and traffic are two distinct and mass-equivalent POA sources in NYC, together contributing ~30% of the total OA mass during this study. The OA composition is dominated by secondary species, especially during high PM events. SV-OOA and LV-OOA on average account for 34% and 30%, respectively, of the total OA mass. The chemical evolution of SOA in NYC appears to progress with a continuous oxidation from SV-OOA to LV-OOA, which is further supported by a gradual increase of O/C ratio and a simultaneous decrease of H/C ratio in total OOA. Detailed analysis of NOA (5.8% of OA) presents evidence that organic nitrogen species such as amines might have played an important role in the atmospheric processing of OA in NYC, likely involving both acid-base chemistry and photochemistry. In addition, analysis of air mass trajectories and satellite imagery of aerosol optical depth (AOD) indicates that the high potential source regions of secondary sulfate and aged OA are mainly located in regions to the west and southwest of the city
Background and Purpose-Periodontal and other infections have been suggested as potential risk factors for stroke. This study evaluates periodontal disease and tooth loss as risk factors for ischemic stroke. Methods-The study population consisted of 41 380 men who were free of cardiovascular disease and diabetes at baseline.Periodontal disease history was assessed by mailed validated questionnaires. During 12 years of follow-up, stroke incidence was assessed and subclassified by use of medical history, medical records, and imaging reports. Hazard ratios (HRs) were adjusted for age, amount smoked, obesity, alcohol, exercise, family history of cardiovascular disease, multivitamin use, vitamin E use, profession, baseline reported hypertension, and hypercholesterolemia. Sex and socioeconomic status were inherently controlled for by restriction. Confounding variables were updated in the analyses for each 2-year follow-up interval. Results-We documented 349 ischemic stroke cases during the follow-up period. Men who had Յ24 teeth at baseline were at a higher risk of stroke compared to men with Ն25 teeth (HRϭ1.57; 95% CI, 1.24 to 1.98
Heterogeneous reactions of oleic acid aerosol particles with ozone are studied below 1% relative humidity. The particles have inert polystyrene latex cores (101-nm diameter) coated by oleic acid layers of 2 to 30 nm. The chemical content of the organic layer is monitored with increasing ozone exposure by using an aerosol mass spectrometer. The carbon-normalized percent yields of particle-phase reaction products are 20-35% 9-oxononanoic acid, 1-3% azelaic acid, 1-3% nonanoic acid, and 35-50% other organic molecules (designated as CHO T ). There is approximately 25% evaporation, presumably as 1-nonanal. To explain the formation of CHO T molecules and the low yields of azelaic and nonanoic acids, we suggest a chemical mechanism in which the Criegee biradical precursors to azelaic acid and nonanoic acid are scavenged by oleic acid to form CHO T molecules. These chemical reactions increase the carbon-normalized oxygen content (z/x) of the C x H y O z layer from 0.1 for unreacted oleic acid to 0.25 after high ozone exposure. Under the assumption that oxygen content is a predictor of hygroscopicity, our results suggest an increased cloud condensation nuclei activity of atmospherically aged organic particles that initially have alkene functionalities.
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