[Pollution Characteristics，Source Analysis，and Activity Analysis of Atmospheric VOCs During Winter and Summer Pollution in Zhengzhou].

In order to study the pollution characteristics of volatile organic compounds （VOCs）， continuous monitoring of VOCs in two pollution processes was conducted in June and December 2021 in Zhengzhou. Combined with meteorological conditions， the pollution characteristics， source contributions， and reactivity of VOCs in winter and summer were compared and analyzed. The results showed that the volume fraction of atmospheric VOCs in two episodes were （27.92±12.68）×10-9 and （24.30±5.93）×10-9， respectively. The volume fraction of atmospheric VOCs in the haze pollution process in winter was larger than that in the ozone pollution process in summer. The analysis results of winter sources were as follows： industrial source （27.0%）， motor vehicle source （22.5%）， combustion source （20.1%）， solvent use source （16.3%）， and oil and gas volatilization source （14.1%）. The analysis results of summer sources were as follows： motor vehicle source （24.8%）， industrial source （24.1%）， solvent source （17.4%）， oil and gas volatilization source （14.2%）， combustion source （11.2%）， and plant source （8.4%）. The results of the smog production model showed that the proportion of days in the synergistic control zone of VOCs during the two pollution processes in summer （66.7%） was smaller than that in winter （100.0%）. The secondary reaction activity results showed that the average ·OH loss rate （L·OH） values in winter and summer were 4.12 s-1 and 4.75 s-1， respectively. The average ozone formation potential （OFP） values in summer were 108.36 µg·m-3. The olefins were dominant in the top ten species due to L·OH and OFP contributions in summer. The total SOAFP values in winter in Zhengzhou were 54.38 µg·m-3. Among the top ten species contributing to SOAFP in winter， nine were aromatic hydrocarbons.

[Effect of transposase on the transposition activity of piggyBac transposon transfected into Toxoplasma gondii].

To determine the transfection efficiency about PBase to piggyBac transposon in transfecting to Toxoplasma gondii, T. gondii RH strain tachyzoites were transfected with plasmid PB-Toxo-RFP which was expressed piggyBac transposon with a red fluorescent protein and Toxo-PBase plasmid which is a transposable enzyme. T. gondii tachyzoites were transfected with PB-Toxo-RFP plasmid alone as control group. The expression of red fluorescent protein was detected by flow cytometry at 24 h after transfection. The transposition efficiency in PB-Toxo-RFP+Toxo-PBase group and PB-Toxo-RFP group was 73% and 43%, respectively (P < 0.01). It suggests that the PBase transposase can improve the transfection efficiency of piggyBac transposon in T. gondii tachyzoites.