When a Twist Makes a Difference: Exploring PCET and ESIPT on a Nonplanar Hydrogen-Bonded Donor-Acceptor System.

Bioinspired benzimidazole-phenol constructs with an intramolecular hydrogen bond connecting the phenol and the benzimidazole have been synthesized to study both proton-coupled electron transfer (PCET) and excited-state intramolecular proton transfer (ESIPT) processes. Strategic incorporation of a methyl group disrupts the coplanarity between the aromatic units, causing a pronounced twist, weakening the intramolecular hydrogen bond, decreasing the phenol redox potential, reducing the chemical reversibility, and quenching the fluorescence emission. Infrared spectroelectrochemistry and transient absorption spectroscopy confirm the formation of the oxidized product upon PCET and probe excited-state relaxation mechanisms, respectively.

Durability of annuloplasty in patients with atrial functional mitral regurgitation associated with atrial fibrillation.

Objective: To determine the durability of mitral valve repair (MVr) with complete ring or flexible band annuloplasty in patients with atrial functional mitral regurgitation (AFMR) due to atrial fibrillation (AF) and identify risk factors associated with postoperative recurrence of mitral regurgitation.

Methods: Between January 1, 2000, and January 1, 2023, 194 adults with a history of AF underwent MVr with annuloplasty alone for moderate/severe AFMR. Exclusion criteria were prior cardiac surgery, additional repair techniques, ejection fraction <45%, ischemic heart disease, aortic valve disease, mitral annular calcification, and concomitant procedures other than surgical ablation or tricuspid repair/replacement.

American Association for Thoracic Surgery Quality Gateway: A surgeon case study of its application in adult cardiac surgery for quality assurance.

Objective: To demonstrate the application of American Association for Thoracic Surgery Quality Gateway (AQG) outcomes models to a Surgeon Case Study of quality assurance in adult cardiac surgery.

Methods: The case study includes 6989 cardiac and thoracic aorta operations performed in adults at Cleveland Clinic by a single surgeon between 2001 and 2023. AQG models were used to predict expected probabilities for operative mortality and major morbidity and to compare hospital outcomes, surgery type, risk profile, and individual risk factor levels using virtual (digital) twin causal inference.

The p66Shc Protein Mediates Insulin Resistance and Secretory Dysfunction in Pancreatic β-Cells Under Lipotoxic Conditions.

We evaluated the role of the p66Shc redox adaptor protein in pancreatic β-cell insulin resistance that develops under lipotoxic conditions and with excess body fat. Prolonged exposure to palmitate in vitro or the presence of overweight/obesity augmented p66Shc expression levels and caused an impaired ability of exogenous insulin to increase cellular insulin content and secreted C-peptide levels in INS-1E cells and human and murine islets. In INS-1E cells, p66Shc knockdown resulted in enhanced insulin-induced augmentation of insulin content and C-peptide secretion and prevented the ability of palmitate to impair these effects of insulin.