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The synthesis of chiral α-azaheteroaryl oxiranes via enantioselective catalysis is a formidable challenge due to the required complex stereoselectivity and diverse N-heterocyclic structures. These compounds play a crucial role in developing bioactive molecules, where precise chirality significantly influences biological activity. Here we show that using chiral phosphoric acid as a catalyst, our method efficiently addresses these challenges. This technique not only achieves high enantio- and diastereoselectivity but also demonstrates superior chemo- and stereocontrol during the epoxidation of alkenyl aza-heteroarenes. Our approach leverages a synergistic blend of electrostatic and hydrogen-bonding interactions, enabling the effective activation of both substrates and hydrogen peroxide. The resulting chiral oxiranes exhibit enhanced diversity and functionality, aiding the construction of complex chiral azaaryl compounds with contiguous stereocenters. Kinetic and density functional theory studies elucidate the mechanism, highlighting chiral phosphoric acid's pivotal role in this intricate enantioselective process. Chiral azaarenes hold critical importance in pharmaceutical research due to their significant impact on drug efficacy and selectivity. Herein, the authors report the synthesis of chiral α-azaheteroaryl oxiranes via catalytic enantioselective epoxidation of alkenyl aza-heteroarenes using chiral phosphoric acid and hydrogen peroxide. [ABSTRACT FROM AUTHOR]

Objective To analyze the influencing factors and improvement paths of the service capacity of standardized township health centers in Guangxi under the background of "high-quality service at the grassroots level", providing useful reference for further deepening reform and promoting the healthy development of rural medical and health systems. Methods By the end of 2021, township health centers that have reached the recommended standard of "quality service primary line" service ability were selected as the research samples, and the coupled coordination degree model was combined with fuzzy set qualitative comparative analysis method to carry out empirical analysis. Results Single factors cannot constitute a necessary condition for improving or decreasing the service capacity of township health centers. There are a total of four configuration paths for improving the service capacity of township health centers in Guangxi, among which the core sufficient conditions for playing a leading role are the number of high-level practicing (assistant) physicians, the number of registered nurses, and coupling coordination scheduling. The overall consistency of the solution is 0.920 (≥0.8), and the model has strong explanatory power. Conclusion The improvement of service capacity in township health centers in Guangxi is facilitated by the synergistic effect of multiple factors both internally and externally. The optimization and expansion of grassroots talent teams is the core combination element for the improvement of service capacity in township health centers, and the coupling and coordinated development of medical resource allocation and economy is the key element for the improvement of service capacity. [ABSTRACT FROM AUTHOR]

The summer precipitation in Northeast China (NEC) can usually be divided into two stages, namely the Northeast China cold vortex (NECV) influencing stage in early summer (May–June) and the monsoon influencing stage in midsummer (July–August). In this study, the influence of NECV on the precipitation at multi‐timescales during different summer periods is studied. The results show that even in midsummer, though the effect of the western Pacific subtropical high is strengthened, the NECV still has the major impact on the precipitation over NEC. High co‐variability could be found between the daily precipitation and the NECV index in each month. The running correlation with an 11‐day window between precipitation and the NECV index also proves that the NECV has large impact on the precipitation over NEC during the whole summer. Key linkage of NECVs and the precipitation in midsummer can still be detected in synoptic extreme rainfall events. The composite analysis shows that, for the heavy rainfall extremes in NEC, the dominant circulation is an obvious 'negative–positive–negative' vorticity pattern at high latitudes of Asia. The positive vorticity in the pattern corresponds to stronger and more active NECV. That means the NECV is still the most critical factor affecting the NEC precipitation in midsummer. [ABSTRACT FROM AUTHOR]