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In this study, PM 2.5 samples were collected synchronously at Gaoxin and Linxiao in Luoyang City during autumn and winter (4 October 2018 to 30 January 2019). Sixteen priority polycyclic aromatic hydrocarbons (PAHs) associated with fine particulate matter were analyzed by gas chromatography mass spectrometry (GC-MS). The concentrations and composition characteristics of the PAHs on clean and polluted days were studied. Diagnostic ratio analysis and principal component analysis (PCA) were used to identify the emission sources of PM 2.5 -bound PAHs and the equivalent carcinogenic concentration of benzo[a]pyrene (BaP) and incremental lifetime cancer risks (ILCRs) model were applied to evaluate health risks. During the sampling period, the concentrations of PAHs at Gaoxin and Linxiao ranged 24.33-90.26 ng·m -3 and 23.81-76.99 ng·m -3 , respectively. With the increase in PM 2.5 pollution, PAH concentrations increase significantly (the mean PAH concentration on polluted days was approximately 1.3 times higher than during clean days). PAH profiles at different polluting levels were similar; 4-ring PAHs (43%-48%) > 5-6 ring PAHs (32%-35%) > 2-3-ring PAHs (20%-22%). Diagnostic ratios and PCA demonstrated that PAHs in the study area were mainly derived from combustion sources including coal combustion, biomass burning, and motor vehicle emissions. The coal combustion was the main pollution source in the study area (clean days=49.28%-56.38%, polluted days=49.44%-60.60%). The results of the equivalent carcinogenic concentration of benzo[a]pyrene (BaP) and ILCR model revealed that the human health risk on polluted days was higher. Moreover, the cancer risks from adult exposure to PAHs were higher than those child exposure, which has an acceptable level of risk (<10 -6 ).

This study examined the moderating effect of gender on the relationship between cognitive social capital and formal volunteering among older adults in urban China. Cognitive social capital refers to individuals' perceptions of their social relationships in local communities. We used quota sampling to recruit 456 older adults aged 60 years and older from 16 communities of Gusu district, Suzhou city, in late 2015. Multiple group analysis was used to examine the proposed model. Gender had a moderating effect on the relationship between cognitive social capital and volunteering. The associations between cognitive social capital and volunteering were higher among older men than older women. The findings highlight the important role of cognitive social capital in influencing formal volunteering among older adults in urban Chinese contexts. The findings are particularly important for enhancing volunteering among older adults across different social and economic backgrounds. Policy and intervention implications are discussed.

Developing countries such as China are undergoing rapid urban expansion and land use change. Urban expansion regulation has been a significant research topic recently, especially in Eastern China, with a high urbanization level. Among others, roads are an important spatial determinant of urban expansion and have significant influences on human activities, the environment, and socioeconomic development. Understanding the urban road network expansion pattern and its corresponding social and environmental effects is a reasonable way to optimize comprehensive urban planning and keep the city sustainable. This paper analyzes the spatiotemporal dynamics of urban road growth and uses spatial statistic models to describe its spatial patterns in rapid developing cities through a case study of Nanjing, China. A kernel density estimation model is used to describe the spatiotemporal distribution patterns of the road network. A geographically weighted regression (GWR) is applied to generate the social and environmental variance influenced by the urban road network expansion. The results reveal that the distribution of the road network shows a morphological character of two horizontal and one vertical concentration lines. From 2012 to 2016, the density of the urban road network increased significantly and developed some obvious focus centers. The development of the urban road network had a strong correlation with socioeconomic and environmental factors, which however, influenced it at different degrees in different districts. This study enhances the understanding of the effects of socio-economic and environmental factors on urban road network expansion, a significant indicator of urban expansion, in different circumstances. The study will provide useful understanding and knowledge to planning departments and other decision makers to maintain sustainable development.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a major cause of nosocomial infections and posed challenges on clinical treatments. The main objective of this study was to determinate the genetic characteristics of the NDM-19-producing CRKP strain SCM96. From 2015 to 2017, 18 CRKP strains were recovered from sputum samples of patients in respiratory medicine in 6 hospitals from 5 provinces and cities in China. Polymerase chain reaction results for carbapenem resistance genes detection showed strain SCM96 carried bla NDM-19 . Three types of transconjugants harboring different plasmids were selected by conjugation experiment. The Whole Genome Sequencing (WGS) was performed using the PacBio RS platform. The genome size of SCM96 was 5,579,775 bp and composed of chromosomal DNA (5,398,745 bp) and 2 plasmids, IncFII type plasmid pSCM96-1 (134,869 bp) and IncX3 type plasmid pSCM96-2 (46,161 bp). SCM96 belonged to ST15 and K28. In addition to the 4 antibiotic resistance genes located in the chromosome, pSCM96-1 carried a complex resistance region containing 17 resistance genes and several mobile genetic elements (MGEs) like △Tn6029, In4-like integron, and Tn3, and pSCM96-2 had only 1 bla NDM-19 gene. As far as we know, this was the first description of bla NDM-19 in K. pneumoniae. Up to 22 antibiotic resistance genes, several important MGEs, and transferable plasmids might increase the possibility of co-spreading of bla NDM-19 with other resistance genes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Size-resolved samples were collected using a 14-stage impactor during four seasons in Zhengzhou and analyzed for 26 elements to calculate the health risks from atmospheric particle-bound metals. High concentrations of heavy metals were observed in ultrafine (10.2 (Ni)-66.9 (Cd) ng m -3 ) or submicrometer (11.4 (Ni)-134 (Pb) ng m -3 ) mode in winter. Two size-dependent models were used to estimate the deposition of inhaled toxic metals in various regions of the human respiratory system. Results show that heavy metals deposited in the alveolar region ranged from 7.6 (As)-375 (Al) ng m -3 and were almost concentrated in ultrafine and fine modes. Cd (2.2-8.6) may cause accumulative non-carcinogenic health effects on children, and Cr (1.0 × 10 -4 -2.2 × 10 -4 ) may lead to carcinogenic health risks for nearby residents around the sampling site. The major sources by principal component analysis that contributed to Cr and Cd in ultrafine and fine particles were coal combustion, vehicular and industrial emissions. The atmospheric dry deposition fluxes of Cr and Cd were between 0.7 and 1.9 μg m -2 day -1 calculated by a multi-step method. From the environmental and public health perspective, environmental agencies must control the emission of heavy metals in the atmosphere., (Copyright © 2019 Elsevier Ltd. All rights reserved.)