Abstract. New particle formation (NPF) is one of the major sources of atmospheric ultrafine particles. Due to the high aerosol and trace gas concentrations, the mechanism and governing factors for NPF in the polluted atmospheric boundary layer may be quite different from those in clean environments, which is however less understood. Herein, based on long-term atmospheric measurements from January 2018 to March 2019 in Beijing, the nucleation mechanism and the influences of H2SO4 concentration, amine concentrations, and aerosol concentration on NPF are quantified. The collision of H2SO4–amine clusters is found to be the dominating mechanism to initialize NPF in urban Beijing. The coagulation scavenging due to the high aerosol concentration is a governing factor as it limits the concentration of H2SO4–amine clusters and new particle formation rates. The formation of H2SO4–amine clusters in Beijing is sometimes limited by low amine concentrations. Summarizing the synergistic effects of H2SO4 concentration, amine concentrations, and aerosol concentration, we elucidate the governing factors for H2SO4–amine nucleation for various conditions.

Abstract. New particle formation (NPF) is one of the major sources of atmospheric ultrafine particles. Due to the high aerosol and trace gas concentrations, the mechanism and governing factors for NPF in the polluted atmospheric boundary layer may be quite different from those in clean environments, which is however less understood. Herein, based on long-term atmospheric measurements from January 2018 to March 2019 in Beijing, the nucleation mechanism and the influences of H2SO4 concentration, amine concentrations, and aerosol concentration on NPF are quantified. The collision of H2SO4-amine clusters is found to be the dominating mechanism to initialize NPF in urban Beijing. The coagulation scavenging due to the high aerosol concentration is a governing factor as it limits the concentration of H2SO4 amine clusters and new particle formation rates. Besides, the effective amine concentration is another limiting factor in Beijing because amine is sometimes insufficient for nucleation at the kinetic limit. Based on the synergistic effects of these factors on H2SO4-amine nucleation, governing factors for H2SO4-amine nucleation for different conditions are summarized.

1. Process-level understanding of new particle formation in wintertime Beijing was obtained based on measurement performed by state-of-the-art instruments. 2. The analysis of sulfuric acid cluster composition and budget showed that sulfuric acid-base clustering initiated new particle formation. 3. Condensable organic vapors were characterized and demonstrated to have a crucial influence on the growth of newly formed particles.

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Background There are some theoretical concerns for the use of intraoperative cell salvage (ICS) in patients with ectopic pregnancy. This study aimed to observe the impact of ICS on the coagulation function and clinical outcomes of patients with ruptured ectopic pregnancy and severe blood loss. Methods This was a retrospective study of 225 patients with ruptured ectopic pregnancy and severe blood loss treated at the Third Affiliated Hospital of Guangxi Medical University between January 2012 and May 2016. Patients were grouped according to ICS (n = 116) and controls (n = 109, allogenic transfusion and no transfusion). Results Compared with controls, patients with ICS had shorter hospitalization (P = 0.007), lower requirement for allogenic blood products (P < 0.001), and higher hemoglobin levels at discharge (P < 0.001). There were no complications/ adverse reactions. In the ICS group, hemoglobin at discharge (−6.5%, P = 0.002) and thrombin time (−3.7%, P = 0.002) were decreased 24 h after surgery, while 24 h APTT was increased (+4.6%, P < 0.001). In the control group, hemoglobin at discharge (−16.8%, P < 0.001) was decreased after surgery and 24 h APTT was increased (+2.4%, P = 0.045). At discharge, hemoglobin levels were higher in the ICS group (P < 0.001). Conclusion ICS was associated with good clinical outcomes in patients with ruptured ectopic pregnancy and severe blood loss.