[Characteristic Analysis and Source Apportionment of VOCs in Urban Areas of Beijing in Summer].

Refined characterization of volatile organic compound (VOCs) components and source apportionment can provide scientific and effective support for ozone (O3) pollution prevention and control. Using hourly-resolution VOCs online data monitored at urban sites in Beijing from July to August in 2020, the chemical characteristics of VOCs and ozone formation potential (OFP) in environmental receptors during high and low ozone concentration periods were analyzed, and refined source apportionment was conducted with a positive matrix factorization (PMF) model. The results showed that the average φ[total volatile organic compounds (TVOCs)] at the monitoring sites during the observation period was 12.65×10-9, and the φ(TVOCs) during the high and low ozone concentration periods were 13.44×10-9 and 12.33×10-9, respectively, with an OFP of 107.6 µg·m-3and 99.2 µg·m-3, respectively. Ozone production was controlled by VOCs, with the highest reactivity of aromatic hydrocarbons and the top three species contributing to OFP being isoprene, toluene, and m/p-xylene. The main sources of VOCs in environmental receptors during low O3 periods included vehicular emissions (26.4%), background emissions (15.7%), solvent using (13.0%), auto repair (12.8%), secondary generation sources (9.7%), biomass combustion (6.1%), printing industry (5.7%), LNG-fueled vehicles (5.5%), and vegetation emissions (5.0%), of which background emissions, secondary generation, and printing industry sources have been little discussed in recent studies of VOCs source apportionment in Beijing. The contribution of auto repair sources and secondary generation sources increased by 3.4% and 2.6%, respectively, during the high O3 periods compared to those during the low O3 periods, and vehicular emissions remained the most significant source of VOCs contribution in the urban area of Beijing. Vegetation emissions rose from 07:00 pm and reach a maximum in the late afternoon. The contribution of background emission sources was less variable; vehicular emissions and LNG-fueled vehicle sources showed a morning and evening peak, with a relatively low contribution in the afternoon.

Overexpression of Protein Phosphatase 2 Regulatory Subunit B"Alpha Promotes Glycolysis by Regulating Hexokinase 1 in Hepatocellular Carcinoma.

Objective: To investigate the regulatory relationship of Protein Phosphatase 2 Regulatory Subunit B"Alpha ( PPP2R3A) and hexokinase 1 ( HK1) in glycolysis of hepatocellular carcinoma (HCC). Methods: In HepG2 and Huh7 cells, PPP2R3A expression was silenced by small interfering RNA (siRNA) and overexpression by plasmid transfection. The PPP2R3A-related genes were searched by RNA sequencing. Glycolysis levels were measured by glucose uptake and lactate production. QRT-PCR, ELISA, western blot and immunofluorescence assay were performed to detect the changes of PPP2R3A and HK1. Cell proliferation, migration and invasion assay were used to study the roles of HK1 regulation by PPP2R3A. Results: RNA sequencing data revealed that PPP2R3A siRNA significantly downregulated the expression of HK1. PPP2R3A gene overexpression promotes, while gene silencing suppresses, the level of HK1 and glycolysis in HCC cells. In HCC tissue samples, PPP2R3A and HK1 were colocalized in the cytoplasm, and their expression showed a positive correlation. HK1 inhibition abrogated the promotion of glycolysis, proliferation, migration and invasion by PPP2R3A overexpression in liver cancer cells. Conclusion: Our findings showed the correlation of PPP2R3A and HK1 in the glycolysis of HCC, which reveals a new mechanism for the oncogenic roles of PPP2R3A in cancer.

Microarray Expression Profile of Circular RNAs in Heart Tissue of Mice with Myocardial Infarction-Induced Heart Failure.

BACKGROUND/AIMS: Myocardial infarction (MI) is a serious complication of atherosclerosis associated with increasing mortality attributable to heart failure. This study is aimed to assess the global changes in and characteristics of the transcriptome of circular RNAs (circRNAs) in heart tissue during MI induced heart failure (HF). METHODS: Using a post-myocardial infarction (MI) model of HF in mice, we applied microarray assay to examine the transcriptome of circRNAs deregulated in the heart during HF. We confirmed the changes in circRNAs by quantitative PCR. RESULTS: We revealed and confirmed a number of circRNAs that were deregulated during HF, which suggests a potential role of circRNAs in HF. CONCLUSIONS: The distinct expression patterns of circulatory circRNAs during HF indicate that circRNAs may actively respond to stress and thus serve as biomarkers of HF diagnosis and treatment.

[Risk factors associated with postoperative complications after reoperation for recurrent Crohn disease].

OBJECTIVE: To evaluate the risk factors of postoperative complications after reoperation for recurrent Crohn disease(CD). METHODS: From 1995 to 2009, 65 patients undergoing reoperation for recurrent CD were identified in the First Affiliated Hospital of Fujian Medical University. Risk factors of postoperative complications were analyzed. These patients were matched by age to 65 patients undergoing primary operation and treatment outcomes were compared between primary operation and reoperation. RESULTS: Postoperative complications were observed in 25 cases(38.5%) undergoing reoperation for CD recurrence and the rate of postoperative complication was higher than that after primary operation(12.3%). Postoperative complications rate in patients with stoma was significantly lower than those without stoma(15.8% vs. 47.8%, χ(2)=5.831, P=0.016). Compared to primary operation, reoperation had longer operative time, more severe intraperitoneal adhesion, and a longer postoperative hospital stay(all P<0.05). CONCLUSION: Reoperation for CD recurrence is associated with higher postoperative complications. Temporary stoma may decrease the rate of postoperative complication.