[Sensitivity Analysis of Atmospheric Ozone and Source Apportionment of Volatile Organic Compounds in Yinchuan City].

Based on the observation data of O concentration in Yinchuan in 2022, the monthly variation characteristics of O concentrations were analyzed. Further, based on the observation data of meteorological elements, conventional pollutants, and volatile organic compounds （VOCs） concentrations at an urban site in Yinchuan from May to July, the difference in meteorological elements and precursor concentrations between the polluted days and the non-polluted days were compared. Then, the O sensitivity and the VOCs sources were discussed using the Framework for 0-D Atmospheric Modeling （F0AM） and positive matrix factorization （PMF） model, respectively.

[The role of the ubiquitin proteasome system and PP2A in spermatogenesis].

The ubiquitin proteasome system (UPS) plays an important role in cell degradation, and is involved in many biological processes such as cell cycle regulation, immune response, DNA damage repair, and signal transduction. It also acts a crucial part in spermatogenesis by selectively degrading proteins and regulating such processes as DNA repair and protamine histone replacement. PP2A, as an essential serine/threonine phosphatase, participates in a variety of life activities.

Short communication: Chemical structure, concentration, and pH are key factors influencing antimicrobial activity of conjugated bile acids against lactobacilli.

Effects of chemical structure, concentration, and pH on antimicrobial activity of conjugated bile acids were investigated in 4 strains of lactobacilli. Considerable differences were observed in the antimicrobial activity between the 6 human conjugated bile acids, including glycocholic acid, taurocholic acid, glycodeoxycholic acid, taurodeoxycholic acid, glycochenodeoxycholic acid, and taurochenodeoxycholic acid. Glycodeoxycholic acid and glycochenodeoxycholic acid generally showed significantly higher antimicrobial activity against the lactobacilli, but glycocholic acid and taurocholic acid exhibited the significantly lower antimicrobial activity.