Sr-bearing marine barite [(Bax, Sr1−x)SO4] cycling has been widely used to reconstruct geochemical evolutions of paleoenvironments. However, an understanding of barite precipitation in the ocean, which is globally undersaturated with respect to barite, is missing. Moreover, the reason for the occurrence of higher Sr content in marine barites than expected for classical crystal growth processes remains unknown. Field data analyses suggested that organic molecules may regulate the formation and composition of marine barites; however, the specific organic–mineral interactions are unclear. Using in situ grazing incidence small-angle X-ray scattering (GISAXS), size and total volume evolutions of barite precipitates on organic films were characterized. The results show that barite forms on organic films from undersaturated solutions. Moreover, from a single supersaturated solution with respect to barite, Sr-rich barite nanoparticles formed on organics, while micrometer-size Sr-poor barites formed in bulk solutions. Ion adsorption experiments showed that organic films can enrich cation concentrations in the adjacent solution, thus increasing the local supersaturation and promoting barite nucleation on organic films, even when the bulk solution was undersaturated. The Sr enrichment in barites formed on organic films was found to be controlled by solid-solution nucleation rates; instead, the Sr-poor barite formation in bulk solution was found to be controlled by solid-solution growth rates. This study provides a mechanistic explanation for Sr-rich marine barite formation and offers insights for understanding and controlling the compositions of solid solutions by separately tuning their nucleation and growth rates via the unique chemistry of solution–organic interfaces.
INTRODUCTION Smoking cessation should be part of tuberculosis (TB) treatment, but a cessation service is not available as part of a routine TB service in most low- and middle-income countries. WHO and The International Union Against Tuberculosis and Lung Disease (The Union) issued a guideline and China implemented a pilot project 5 years ago. This study aimed to determine changes in smoking status among TB patients at 5 years after completion of anti-TB treatment to observe long-term outcome of a smoking cessation project whose baseline characteristics were associated with a relapse of smoking behavior. METHODS A prospective longitudinal study was conducted 5 years after completion of anti-TB treatment to assess changes in patient smoking status against individual baseline data that were entered into a database at the time of TB registration. The patients were tracked by trained village doctors and validated by township health staff. Their smoking status was assessed and entered into the database and analysed. RESULTS Of the 800 TB patients registered at baseline, 650 (81.2%) were tracked. Ninety-one (11.4%) patients died and 59 (7.4%) were lost to follow-up. The rates of remaining non-smoking after 5 years were 82.0%, 63.0%, 49.6%, 43.5% and 30.0%, respectively for non-smokers, ex-smokers, current smokers who received cessation intervention, recent quitters, and current smokers not on a cessation intervention. The odds of smoking relapse were significantly higher for those aged >= 65 years (p=0.003) and registered in Xingguo County (p=0.025). CONCLUSIONS Findings from this study confirmed that non-smokers, ex-smokers and current smokers who received cessation intervention at baseline maintained higher non-smoking rates compared with those who did not receive the intervention. To prevent relapse, intensive cessation support should be given to TB patients aged >= 65 years. TB programme managers need to ensure integration and provision of smoking cessation advice and smoke-free policy in routine TB services.
INTRODUCTION Smoking cessation should be part of tuberculosis (TB) treatment, but a cessation service is not available as part of a routine TB service in most low- and middle-income countries. WHO and The International Union Against Tuberculosis and Lung Disease (The Union) issued a guideline and China implemented a pilot project 5 years ago. This study aimed to determine changes in smoking status among TB patients at 5 years after completion of anti-TB treatment to observe long-term outcome of a smoking cessation project whose baseline characteristics were associated with a relapse of smoking behavior. METHODS A prospective longitudinal study was conducted 5 years after completion of anti-TB treatment to assess changes in patient smoking status against individual baseline data that were entered into a database at the time of TB registration. The patients were tracked by trained village doctors and validated by township health staff. Their smoking status was assessed and entered into the database and analysed. RESULTS Of the 800 TB patients registered at baseline, 650 (81.2%) were tracked. Ninety-one (11.4%) patients died and 59 (7.4%) were lost to follow-up. The rates of remaining non-smoking after 5 years were 82.0%, 63.0%, 49.6%, 43.5% and 30.0%, respectively for non-smokers, ex-smokers, current smokers who received cessation intervention, recent quitters, and current smokers not on a cessation intervention. The odds of smoking relapse were significantly higher for those aged >= 65 years (p=0.003) and registered in Xingguo County (p=0.025). CONCLUSIONS Findings from this study confirmed that non-smokers, ex-smokers and current smokers who received cessation intervention at baseline maintained higher non-smoking rates compared with those who did not receive the intervention. To prevent relapse, intensive cessation support should be given to TB patients aged >= 65 years. TB programme managers need to ensure integration and provision of smoking cessation advice and smoke-free policy in routine TB services.
BACKGROUND: Identifying subjects with a high risk of ischemic stroke is fundamental for prevention of the disease. Both genetic and environmental risk factors contribute to ischemic stroke, but the underlying epigenetic mechanisms which mediate genetic and environmental risk effects are not fully understood. The aim of this study was to explore whether DNA methylation loci located in the ATP-binding cassette G1 (ABCG1) and apolipoprotein E (APOE) genes, both involved in the metabolism of lipids in the body, are related to ischemic stroke, using the Fangshan/Family-based Ischemic Stroke Study in China. We also tested if these CpG sites were associated with early signs of cardiovascular atherosclerosis (carotid intima-media thickness (cIMT), ankle-brachial index (ABI), and brachial-ankle pulse wave velocity (baPWV)). RESULTS: DNA methylation at the cg02494239 locus in ABCG1 was correlated with ischemic stroke after adjusting for gender, previous history of diabetes and hypertension, smoking, drinking, body mass index, and blood lipid levels (above vs below mean, OR = 2.416, 95% CI 1.024-5.700, P = 0.044; 75-100% percentile vs 0-25% percentile, OR = 4.461, 95% CI 1.226-16.225, P = 0.023). No statistically significant associations were observed for the cg06500161 site in ABCG1 and the cg14123992 site in APOE with ischemic stroke. The study detected that hypermethylation of the ABCG1 gene was significantly associated with cIMT, hypermethylation of the APOE gene was significantly related to ABI, and methylation of the APOE gene was statistically negatively correlated with baPWV. The above relationships demonstrated gender differences. CONCLUSIONS: These findings suggest that epigenetic modification of ABCG1 and APOE may play a role in the pathway from disturbed blood lipid levels to the development of cardiovascular diseases. Future prospective validation of these findings is warranted.
The health impacts associated with engineered nanoparticles (ENPs) released into the atmosphere have not been adequately assessed. Such impacts could potentially arise from the toxicity associated with condensable atmospheric secondary organic material (SOM), or changes in the SOM composition induced by ENPs. Here, these possibilities are evaluated by investigating the oxidative and toxicological evolution of TiO2 and SiO2 nanoparticles which have been coated with SOM from the O-3 or OH initiated oxidation of alpha-pinene. It was found that pristine SiO2 particles were significantly more cytotoxic compared to pristine TiO2 particles. TiO2 in the dark or under UV irradiation catalytically reacted with the SOM, increasing its O/C by up to 55% over photochemically inert SiO2 while having negligible effects on the overall cytotoxicity. Conversely, the cytotoxicity associated with SiO2 coated with SOM was markedly suppressed (by a factor of 9, at the highest exposure dose) with both increased SOM coating thickness and increased photochemical aging. These suppressing effects (organic coating and photo-oxidation of organics) were attributed to a physical hindrance of SiO2-cell interactions by the SOM and enhanced SOM viscosity and hydrophilicity with continued photo-oxidation, respectively. These findings highlight the importance of atmospheric processes in altering the cytotoxicity of ENPs.
Oxidative stress (OS) has been found to be related to accelerated aging and many aging-related health outcomes. Recently, an epigenetic "mortality risk score" (MS) based on whole blood DNA methylation at 10 mortality-related CpG sites has been demonstrated to be associated with all-cause mortality. This study aimed to address the association between OS and MS, and to assess and compare their performance in the prediction of all-cause mortality. For 1448 participants aged 50-75 of the German ESTHER cohort study, the MS was derived from the DNA methylation profiles measured by Illumina HumanMethylation450K Beadchip and the levels of two urinary OS markers, 8-isoprostane (8-iso) and oxidized guanine/guanosine [including 8-hydroxy-2'-deoxyguanosine (8-oxo)], were measured by ELISA kits. Associations between OS markers and the MS were evaluated by linear and ordinal logistic regression models, and their associations with all-cause mortality were examined by Cox regression models. Both OS markers were associated with the MS at baseline. The 8-iso levels and MS, but not 8-oxo levels, were associated with all-cause mortality during a median follow-up of 15.1 years. Fully-adjusted hazard ratios (95% CI) were 1.56 (1.13-2.16) for the 4th quartile of 8-iso levels compared with the 1st, 1.71 (1.27-2.29) and 2.92 (2.03-4.18) for the moderate and high MS defined by 2-5 and > 5 CpG sites with aberrant methylation compared with a MS of 0-1, respectively. After controlling for 8-iso levels, the hazard ratios of MS remained essentially unchanged while the association of 8-iso levels with mortality was attenuated. This study demonstrates that OS is highly associated with the epigenetic MS, and the latter at the same time has a higher predictive value for all-cause mortality.
The bubbles have a huge influence on the passive millimeter-wave (PMMW) radiation of ship wakes. The bubble distribution is able to be simulated based on the semi-empirical formula of Kelvin wake and turbulence energy attenuation spectrum. With the Maxwell-Garnett (MG) theory, the PMMW radiation of bubbles in different conditions can be calculated. Furthermore, the imaging experiment results are in a good agreement with the mathematical calculation results, which confirms the validity of the simulation model.
Plant height is a key functional trait related to aboveground biomass, leaf photosynthesis and plant fitness. However, large-scale geographical patterns in community-average plant height (CAPH) of woody species and drivers of these patterns across different life forms remain hotly debated. Moreover, whether CAPH could be used as a predictor of ecosystem primary productivity is unknown.We compiled mature height and distributions of 11 422 woody species in eastern Eurasia, and estimated geographic patterns in CAPH for different taxonomic groups and life forms. Then we evaluated the effects of environmental (including current climate and historical climate change since the Last Glacial Maximum (LGM)) and evolutionary factors on CAPH. Lastly, we compared the predictive power of CAPH on primary productivity with that of LiDAR-derived canopy-height data from a global survey.Geographic patterns of CAPH and their drivers differed among taxonomic groups and life forms. The strongest predictor for CAPH of all woody species combined, angiosperms, all dicots and deciduous dicots was actual evapotranspiration, while temperature was the strongest predictor for CAPH of monocots and tree, shrub and evergreen dicots, and water availability for gymnosperms. Historical climate change since the LGM had only weak effects on CAPH. No phylogenetic signal was detected in family-wise average height, which was also unrelated to the tested environmental factors. Finally, we found a strong correlation between CAPH and ecosystem primary productivity. Primary productivity showed a weaker relationship with CAPH of the tallest species within a grid cell and no relationship with LiDAR-derived canopy height reported in the global survey. Our findings suggest that current climate rather than historical climate change and evolutionary history determine the geographical patterns in CAPH. However, the relative effects of climatic factors representing environmental energy and water availability on spatial variations of CAPH vary among plant life forms. Moreover, our results also suggest that CAPH can be used as a good predictor of ecosystem primary productivity.
Perceptual learning is often interpreted as learning of fine stimulus templates. However, we have proposed that perceptual learning is more than template learning, in that more abstract statistical rules may have been learned, so that learning can transfer to stimuli at different precisions. Here we provide new evidence to support this view: Perceptual learning of Vernier discrimination at high noise, which has thresholds approximately 10 times as much as those at zero noise, is initially non-transferrable to zero noise. However, additional exposure to a noise-free Vernier-forming Gabor, which is ineffective alone, not only maximizes zero-noise fine Vernier discrimination, but also further enhances high-noise Vernier performance. Such high-threshold coarse Vernier training cannot impact the fine stimulus template directly. One plausible explanation is that the observers have learned the statistical rules that can apply to standardized input distributions to improve discrimination, regardless of the original precision of these distributions.
