The effects of autophagy on vascular endothelial cells induced by airborne PM2.5.

The purpose of this study was to examine the direct toxicity of PM2.5 collected from Beijing on human umbilical vein endothelial cells (HUVEC). A Cell Counting Kit 8 (CCK8) assay demonstrated that PM2.5 exposure decreased the proliferation of HUVECs in a dose-dependent manner. We also found that PM2.5 exposure induced autophagy in HUVECs, as evidenced by: (1) an increased number of double-membrane vesicles; (2) enhanced conversion and punctuation of the microtubule-associated protein light chain 3 (LC3); and (3) decreased levels of the selective autophagy substrate p62 in a time-dependent manner. Furthermore, promoting autophagy in PM2.5-exposed HUVECs with rapamycin increased the cell survival rate, whereas inhibiting autophagy via 3-methyladenine significantly decreased cell survival. These results demonstrate that PM2.5 exposure can induce cytotoxicity and autophagy in HUVECs and that autophagy play a protective role against PM2.5-induced cytotoxicity. The findings of the present study imply a direct toxic effect of PM2.5 on HUVECs and provide novel insight into the mechanism of cardiovascular diseases caused by PM2.5 exposure.

Quantitative mapping of patented technology - The case of electrical conducting polymer nanocomposite.

This study aims to obtain global technology evolution by constructing and analyzing patent citation network and patent citation map for the field of electrical conducting polymer nanocomposite. A total of 1421 patents are retrieved from USPTO patent database and patent citation network is established by combing both patent citation and social network analysis. Network properties, e.g. Degree Centrality, Betweenness Centrality, and Closeness Centrality, are calculated for representing several technology evolution mechanisms that first proposed in this study. Also, a distance-based patent citation map is constructed by calculating relative distances and positions of patents in the patent citation network. Quantitative ways of exploring technology evolution are investigated in this study to unveil important or emerging techniques as well as to demonstrate dynamics and visualization of technology evolutions.