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Despite the implementation of the Clean Air Action Plan by the Chinese government in 2013, the issue of increasing surface ozone (O 3) concentrations remains a significant environmental concern in China. In this study, we used an improved regional climate–chemistry–ecology model (RegCM-Chem-YIBs) to investigate the impact of anthropogenic emissions, meteorological factors, and CO 2 changes on summer surface O 3 levels in China from 2008 to 2018. Compared to its predecessor, the model has been enhanced concerning the photolysis of O 3 and the radiative impacts of CO 2 and O 3. The investigations showed anthropogenic emissions were the primary contributor to the O 3 increase in China, responsible for 4.08–18.51 ppb in the North China Plain. However, changed meteorological conditions played a crucial role in decreasing O 3 in China and may have a more significant impact than anthropogenic emissions in some regions. Changed CO 2 played a critical role in the variability of O 3 through radiative forcing and isoprene emissions, particularly in southern China, inducing an increase in O 3 on the southeast coast of China (0.28–0.46 ppb) and a decrease in southwest and central China (- 0.51 to - 0.11 ppb). Our study comprehensively analyzed O 3 variation across China from various perspectives and highlighted the importance of considering CO 2 variations when designing long-term O 3 control policies, especially in high-vegetation-coverage areas. [ABSTRACT FROM AUTHOR]

Currently, the major global economies have entered an aging society. The promotion of physical activity is an important way to improve the health level of the elderly, and the study of health geography is a popular interdisciplinary research topic. This study selected 12 representative districts in Guoyu City, Jiangsu Province, to conduct a questionnaire survey on the activity range and behavior pattern of leisure walking among the elderly. We analyzed the relationship between the environment factors of different blocks and the walking activities of the elderly. The results showed that: (1) A range of 800 m from home is the most important leisure walking space for the urban elderly, and a distance between 800 and 1500 m is an important optional leisure walking space. (2) The density of open green space, commercial facilities, and public service facilities has a significant impact on the elderly's leisure walking activities. (3) The socioeconomic background and health status of the elderly have a significant impact on their leisure walking activities. Healthy physical conditions can motivate the elderly to form good exercise habits. The government must optimize the built environment elements in a targeted living space to encourage physical activity among the elderly. [ABSTRACT FROM AUTHOR]

Interactions between aerosols and gases in the atmosphere have been the focus of an increasing number of studies in recent years. Here, we focus on aerosol effects on tropospheric ozone that involve meteorological feedbacks induced by aerosol-radiation interactions. Specifically, we study the effects that involve aerosol influences on the transport of gaseous pollutants and on atmospheric moisture, both of which can impact ozone chemistry. For this purpose, we use the UK Earth System Model (UKESM1) with which we performed sensitivity simulations including and excluding the aerosol direct radiative effect (ADE) on atmospheric chemistry, and focused our analysis on an area with high aerosol presence, namely China. By comparing the simulations, we found that ADE reduced the shortwave radiation by 11 % in China, and consequently led to lower turbulent kinetic energy, weaker horizontal winds and a shallower boundary layer (with a maximum of 102.28 m reduction in north China). On the one hand, the suppressed boundary layer limited the export and diffusion of pollutants, and increased the concentration of CO, SO2, NO, NO2, PM2.5 and PM10 in the aerosol rich regions. The NO / NO2 ratio generally increased and led to more ozone depletion. On the other hand, the boundary layer top acted as a barrier that trapped moisture at lower altitudes and reduced the moisture at higher altitudes (the specific humidity was reduced by 1.69 % at 1493 m averaged in China). Due to reduced water vapor, fewer clouds were formed, and more sunlight reached the surface, so the photolytical production of ozone increased. Under the combined effect of the two meteorology feedback methods, the annual average ozone concentration in China declined by 2.01 ppb (6.2 %), which was found to bring the model in closer agreement with surface ozone measurements from different parts of China. [ABSTRACT FROM AUTHOR]

Cerenkov luminescence imaging can image radiopharmaceuticals using a high-sensitivity charge-coupled device camera. However, Cerenkov luminescence emitted from the radiopharmaceuticals is weak and has low penetration depth in biologic tissues, which severely limits the sensitivity and accuracy of Cerenkov luminescence imaging. This study presents 3-dimensional (3D) radiopharmaceutical-excited fluorescence tomography (REFT) using europium oxide (EO) nanoparticles, which enhances the Cerenkov luminescence signal intensity, improves the penetration depth, and obtains more accurate 3D distribution of radiopharmaceuticals., Methods: The enhanced optical signals of various radiopharmaceuticals (including Na 131 I, 18 F-FDG, 68 GaCl 3 , Na 99m TcO 4 ) by EO nanoparticles were detected in vitro. The location and 3D distribution of the radiopharmaceuticals of REFT were then reconstructed and compared with those of Cerenkov luminescence tomography through the experiments with the phantom, artificial source-implanted mouse models, and mice bearing hepatocellular carcinomas., Results: The mixture of 68 GaCl 3 and EO nanoparticles possessed the strongest optical signals compared with the other mixtures. The in vitro phantom and implanted mouse studies showed that REFT revealed more accurate 3D distribution of 68 GaCl 3 REFT can detect more tumors than small-animal PET in hepatocellular carcinoma-bearing mice and achieved more accurate 3D distribution information than Cerenkov luminescence tomography., Conclusion: REFT with EO nanoparticles significantly improves accuracy of localization of radiopharmaceuticals and can precisely localize the tumor in vivo., (© 2017 by the Society of Nuclear Medicine and Molecular Imaging.)