[Compositional Characteristics of Volatile Organic Compounds in Typical Industrial Areas of the Pearl River Delta: Importance of Oxygenated Volatile Organic Compounds].

Volatile organic compounds (VOCs) are key components of tropospheric chemistry, of which industrial emissions are an important source of atmospheric VOCs. In this study, online measurements of 74 VOCs were made in a typical industrial area of the Pearl River Delta in southern China during the early summer of 2021. The mean volume mixing ratio of total volatile organic compounds (TVOC) was (81.9±45.4)×10-9 during the campaign. Among them, oxygenated volatile organic compounds (OVOCs) accounted for the largest fraction of TVOC, with an average of 51.5%, followed by aromatics, accounting for 19.4% of TVOC. The proportion of OVOCs in TVOC gradually increased with the increase in TVOC concentration. Industry-related emissions were the main contributors to aromatics and OVOCs in this region. Aromatics and OVOCs were the two major contributors to the ozone formation potential (OFP), accounting for 56.4% and 26.7%, respectively. Furthermore, OVOCs also contributed 40.0% of the total ·OH reactivity from VOCs. Xylenes, toluene, acrolein, and ethyl acetate had a greater contribution to the formation of secondary pollution; thus, these species should be given priority for controlling secondary pollution. Our results underscore the severity of OVOCs pollution in industrial areas and the important roles of OVOCs in secondary pollution.

[Effects of ß-amyloid-induced microglial inflammatory supernatant on neuronal apoptosis].

OBJECTIVE: To study the effects of neuronal apoptosis under the induction of ß-amyloid inflammatory supernatant. METHODS: The neurons were intervened by ß-amyloid-induced inflammatory supernatant at the concentration of Aß1-42 at 125 nmol/L. And the expressions of Bcl-2, caspase-3, PARP and neuronal apoptosis were detected. RESULTS: The caspase-3 (14.2 ± 1.8), Bcl-2 (10.6 ± 0.8) positive cells of microglia inflammatory supernatant stimulated group were significantly elevated than the control (2.2 ± 0.6, 5.0 ± 0.3, P < 0.01). Nuclear chromatin was uniform yellow-green fluorescent. And there was significant difference of neuronal apoptosis between microglia inflammatory supernatant group and Aß1-42 directly stimulated group. CONCLUSION: Neuronal apoptosis is induced by caspase-3 in ß-amyloid inflammatory supernatant. One of the important causes is chronic inflammatory process of activated microglia by Aß.