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West China experienced an extremely wet autumn in 2017, and the amount of September–October precipitation is the greatest during 1961–2018. This study explored the physical processes responsible for two primary intraseasonal precipitation events which contribute greatly to such an extremely wet season. The first event peaking in early September is induced by the southward movement of a frontal system from the northern China, which is attributed to the southward displacement of an intraseasonal anticyclonic anomaly. The northerly anomaly associated with the anticyclone advects cold air into West China and thus triggers frontal precipitation. The second event peaking in early October is related to the northward shift and intensification of an intraseasonal anticyclonic anomaly centred over the northwestern Pacific Ocean. The southerly anomaly along the western flank of the anticyclone transports moisture to West China and thus triggers precipitation. The different initiation processes for the two precipitation events may be due to the distinct dynamical and thermal‐dynamical conditions in September and October. West China has sufficient moisture but less dynamical disturbances in September, while it has adequate dynamical disturbances but less moisture in October. [ABSTRACT FROM AUTHOR]

Large-scale circulation anomalies associated with 10–30-day-filtered persistent heavy rainfall events (PHREs) over the middle and lower reaches of the Yangtze River Valley (MLYV) in boreal summer for the period of 1961–2017 were investigated. Two distinct types of PHREs were identified based on configurations of anomalies in the western Pacific subtropical high (WPSH) and South Asian high (SAH) during the peak wet phase. One type, referred to as PSAH, is characterized by eastward extension of the SAH, and the other, referred to as NSAH, featured a westward retreat of the SAH; they both exhibit westward extension of the WPSH. Both types of PHREs are dominated by mei-yu frontal systems. The lower-level circulation anomalies play a crucial role in initiating rainfall but through different processes. Prior to rainfall occurrence, a strong anticyclonic circulation anomaly is over the western North Pacific Ocean (WNP) for the PSAH events and the related southwesterly wind anomaly prevails over southeastern China, which advects moisture into the MLYV, moistens the boundary layer, and induces atmospheric convective instability. For the NSAH events, the WNP anticyclonic circulation is weak while a strong northerly wind is observed north of the MLYV. It brings the cold air mass southward, favoring initiating frontal rainfall over the MLYV. The formation of upper-level circulation anomalies over the MLYV is primarily due to the shift of anomalous circulations from the mid-high latitudes. After the rainfall generation, the precipitation would influence the lower- and upper-level circulation anomalies. [ABSTRACT FROM AUTHOR]

Bioaccessibility and provenance of heavy metals (V, Cr, Co, Ni, Cu, Zn, As, Cd, Ba, Pb) in the park dusts were investigated. The enrichment factors (EFs) indicated that Cd, Cu, and Zn were substantially higher enriched than the other heavy metals. An in vitro test of Solubility Bioaccessibility Research Consortium method (SBRC) and a modified sequential extraction method recommended by the European Community Bureau of Reference (BCR) were used to determine heavy metals bioaccessibility. The average bioaccessibility index (K) of most heavy metals was above 0.2, excluding Ba and Cr. In particular, extremely high bioaccessibilities of Zn (K = 0.83), Cd (K = 0.74), Pb (K = 0.62), and Cu (K = 0.59) were observed in the park dusts. Based on the Pb isotope technique, coal dust, soil parent materials and fertilizers, and traffic sources were accounting for 58%, 35%, and 7% of Pb in the park dust, respectively. The principle component analysis and multiple linear regression (PCA-MLR) results of the additive log-ratio transformation (coal combustion: 56.6%; soil parent materials and fertilizers: 36.8%; traffic sources: 6.6%) were more in good agreement with the Pb isotope technique results. Compared with the original data and the direct logarithmic transformation, the contributions were all positive values in the results of the additive log-ratio transformation, suggesting an effective method to open geochemical component data. Thus, the additive log-ratio transformation has strong interpretability in source appointment as well as better dimension reduction. This study provides an example to explore bioaccessibility in view of binding state and identify sources of multiple heavy metals in the park dust using properly transformed data in conjunction with Pb isotopes technique. Image 1 • Cu, Zn, and Cd were enriched in all samples impacted by anthropogenic sources. • High bioaccessibilities of Zn, Cd, Pb, and Cu were observed in the park dusts. • Heavy metals sources were quantified by PCA-MLR coupled with Pb isotopes. • PCA-MLR with the alr transformation has strong interpretability. [ABSTRACT FROM AUTHOR]

During the COVID-19 outbreak, some patients with COVID-19 pneumonia also suffered from acute abdomen requiring surgical treatment; however, there is no consensus for the treatment of such patients. In this study, we retrospectively reviewed 34 patients with acute abdomen who underwent emergency surgery during the COVID-19 outbreak. Among the 34 patients with acute abdomen, a total of six cases were found with COVID-19 pneumonia (clinical classification for COVID-19 pneumonia: all were the common type). On the premise of similar demographics between both groups, patients with COVID-19 pneumonia had worse indicators of liver and coagulation function. Compared with acute abdomen patients without COVID-19, patients with COVID-19 pneumonia had a longer hospital stay, but there were no significant differences in postsurgical complications (P = 0.58) or clinical outcomes (P = 0.56). In addition, an obvious resolution of lung inflammation after surgery was observed in five COVID-19 patients (83.3%). No new COVID-19 cases occurred during the patients' hospital stays. Therefore, for the common type of COVID-19 pneumonia, emergency surgery could not only improve the outcomes of COVID-19 pneumonia patients with acute abdomen, but also benefit the resolution of pulmonary inflammation.