Intermolecular O-O Bond Formation between High-Valent Ru-oxo Species.

Despite extensive research on water oxidation catalysts over the past few decades, the relationship between high-valent metal-oxo intermediates and the O-O bond formation pathway has not been well clarified. Our previous study showed that the high spin density on O in RuV=O is pivotal for the interaction of two metal-oxyl radical (I2M) pathways. In this study, we found that introducing an axially coordinating ligand, which is favorable for bimolecular coupling, into the Ru-pda catalyst can rearrange its geometry. The shifts in geometric orientation altered its O-O bond formation pathway from water nucleophilic attack (WNA) to I2M, resulting in a 70-fold increase in water oxidation activity. This implies that the I2M pathway is concurrently influenced by the spin density on oxo and the geometry organization of the catalysts. The observed mechanistic switch and theoretical studies provide insights into controlling reaction pathways for homogeneous water oxidation catalysis.

Levosimendan: A New Therapeutical Strategy in Patients with Renal Insufficiency.

Levosimendan, a Ca2 + sensitizer with positive inotropic effects, is primarily employed for the short-term treatment of acute decompensated heart failure (ADHF). Levosimendan exerts renal function protection through various mechanisms, including anti-apoptosis, anti-inflammatory, and antioxidant effects in vivo. Additionally, levosimendan may have a protective effect on individuals with heart failure and renal insufficiency, as well as on renal function impairment after cardiac surgery. However, the application of levosimendan in patients with severe renal dysfunction remains controversial. This article delves into the use of levosimendan in severe renal insufficiency, explores its impact on renal function, and provides a comprehensive overview of its impact on renal function after cardiac surgery.

Safety and efficacy of apixaban versus vitamin K antagonists in patients undergoing dialysis: a systematic review and meta-analysis.

BACKGROUND: This review aims to evaluate the safety and efficacy of apixaban vs. vitamin K antagonists (VKAs) in patients on dialysis. METHODS: All types of studies published on PubMed, Embase, CENTRAL, and Web of Science up to 10 September 2023 and comparing outcomes of apixaban vs. VKA in dialysis patients were eligible. RESULTS: Two randomized controlled trials (RCTs) and six retrospective studies were included. Apixaban treatment was associated with significantly lower risk of major bleeding (RR: 0.61; 95% CI: 0.48, 0.77; I2 = 50%) and clinically relevant non-major bleeding (RR: 0.82, 95% CI: 0.68, 0.98, I2 = 9%) compared to VKA. Meta-analysis also showed that the risk of gastrointestinal bleeding (RR: 0.74, 95% CI: 0.64, 0.85, I2 = 16%) and intracranial bleeding (RR: 0.64, 95% CI: 0.49, 0.84, I2 = 0%) was significantly reduced with apixaban. Meta-analysis showed no difference in the risk of ischemic stroke (RR: 0.40, 95% CI: 0.06, 2.69, I2 = 0%), mortality (RR: 1.26, 95% CI: 0.74, 2.16, I2 = 94%) and recurrent venous thromboembolism (RR: 1.02, 95% CI: 0.87, 1.21, I2 = 0%) between the two groups. Subgroup analysis of RCTs showed no difference in bleeding outcomes. CONCLUSIONS: Low-quality evidence from a mix of RCTs and retrospective studies shows that apixaban may have better safety and equivalent efficacy as compared to VKA in dialysis patients. Apixaban treatment correlated with significantly reduced risk of major bleeding and clinically relevant nonmajor bleeding in observational studies but not in RCTs. The predominance of retrospective data warrants caution in the interpretation of results.

Risks of bleeding and thromboembolic events in patients undergoing colonoscopy on uninterrupted and interrupted anticoagulant therapy in real-world setting.

BACKGROUND: Although anticoagulants may potentially increase the risk of post-colonoscopy bleeding events, temporary discontinuation of medications could elevate the risk of thromboembolism (TE). There is a paucity of data regarding the incidence of bleeding and TE events in patients undergoing colonoscopy while on uninterrupted or interrupted anticoagulant therapy. Therefore, we aimed to ascertain the risks of post-colonoscopy TE and bleeding in patients with continuous or interrupted use of anticoagulant agents. METHODS: The electronic databases of PubMed, Embase, and the Cochrane library were comprehensively searched from inception to March 15, 2024. We identified studies reporting the incidence of bleeding and TE events in patients undergoing colonoscopy with uninterrupted or interrupted anticoagulant therapy. The pooled incidence rate of bleeding and TE events was estimated using a random-effects model. RESULTS: This study included a total of 15 studies involving 63, 017 patients. Overall, the incidence of post-procedural bleeding for uninterrupted and interrupted direct oral anticoagulants (DOACs) was found to be 3.60 % (95 % CI: 1.60 %-5.60 %), and 0.90 % (95 % CI: 0.10 %-10.30 %), respectively. Subgroup analysis revealed that older age patients (≥65 years) had a significantly higher rate of bleeding with uninterrupted DOACs therapy compared to younger age patients (< 65 years) (7.20 % vs. 2.00 %). The highest rate of bleeding was observed in Asia (7.20 %, 95 % CI: 2.20 %-12.10 %). Similarly, the risk of bleeding was significantly increased among patients interrupting DOACs therapy in Asia compared to North America (1.40 % vs. 0.26 %). For patients on uninterrupted and interrupted warfarin, a higher rate of bleeding events was observed in older age patients than younger age patients (4.90 % vs. 0.80 %, and 2.20 % vs. 1.70 %, respectively). Uninterrupted warfarin showed a more significant risk of bleeding in Asia (4.20 %, 95%CI: 1.90 %-6.60 %) compared to North America (1.00 %, 95%CI: 0.50 %-1.50 %). Among those who did not interrupt DOACs therapy, the incidence of TE was the lowest (0.08 %, 95%CI: 0.04 %-0.11 %). CONCLUSION: This study provides a comprehensive assessment of bleeding and TE risks in patients undergoing colonoscopy while receiving uninterrupted or interrupted anticoagulant therapy in the real-world setting. The overall incidence of post-colonoscopy bleeding and TE events is relatively low. However, the uninterrupted DOACs and warfarin are associated with an elevated risk of bleeding, particularly among elderly patients and the Asian population.