We quantified the relationship between atmospheric rivers (ARs) and occurrence and magnitude of extreme precipitation in western U.S. watersheds, using ARs identified by the Atmospheric River Tracking Method Intercomparison Project and precipitation from a high‐resolution regional climate simulation. Our analysis shows the potential of ARs in predicting extreme precipitation events at a daily scale, with Gilbert Skill Scores of ~0.2. Monthly extreme precipitation amount in west coast watersheds is closely related to AR intensity, with correlation coefficients of up to 0.6. The relationship between ARs and precipitation is most significant in the Pacific Northwest and California. Using a K‐means clustering algorithm, ARs can be classified into three categories: weak ARs, flash ARs, and prolonged ARs. Flash ARs and prolonged ARs, though accounting for less than 50% of total AR events, are more important in controlling extreme precipitation patterns and should be prioritized for future studies of hydrological extreme events.

Cholesterol 25-hydroxylase (CH25H) catalyzes the production of , an oxysterol which can play an important role in different biological processes.However, the mechanisms regulating CH25H expression have not been fully elucidated. In this study, we determined that CH25H is highly expressed in mouse liver and peritoneal macrophages. We identified several liver X receptor (LXR) response elements (LXREs) in the human CH25H promoter. In HepG2 cells, activation of LXR by 25-HC or other oxysterols and synthetic ligands [T0901317 (T317) and GW3965] induced CH25H protein expression which was associated with increased CH25H mRNA expression. 25-HC or T317 activated CH25H transcription in an LXRE-dependent manner. Thus, high expressing LXR or LXR activated CH25H expression, and the activation was further enhanced by LXR ligands. In contrast, inhibition of LXR/ expression attenuated 25-HC or T317-induced CH25H expression. Deficiency of interferon  expression reduced, but did not block, LXR ligand-induced hepatic CH25H expression. Activation of LXR also substantially induced macrophage CH25H expression. In vivo, administration of GW3965 to mice increased CH25H expression in both liver and peritoneal macrophages. Taken together, our study demonstrates that 25-HC can activate CH25H expression in an LXR-dependent manner, which may be an important mechanism to exert the biological actions of 25-HC.

MARSI at PICC insertion site is a frequent event among oncology patients. Epidemiological data and independent risk factors are presented in our study, which provide a basis for future study in this area.