Dynamic Interfacial Tension Measurement for the Kinetic Study of Eu(III) Extraction in the NaNO3/Tributyl Phosphate System Based on an Increase in Interfacial Tension.

We demonstrated for the first time that interfacial tension measurements can be used to evaluate the kinetics of the solvent extraction of metal ions. The Eu(III) extraction mechanism in the nitrate ion/tributyl phosphate (TBP) system was investigated on the basis of dynamic interfacial tension. Interestingly, the interfacial tension of the TBP droplet (γ) increased with Eu(III) extraction. This behavior can be explained by the electrocapillary effect. The time dependence of γ was kinetically analyzed, and we demonstrated that the rate-determining process was the interfacial reaction of Eu(III). Furthermore, the dependence of the mass transfer rate constant upon the concentration of the nitrate ions revealed that two nitrate ions were involved in the interfacial reaction during Eu(III) extraction. However, no change in the rate constant upon TBP concentration was observed, because the change in the TBP concentration did not affect the electrocapillary effect. We determined the forward and backward reaction rates to be k1 = (1.5 ± 0.7) × 10-6 m M-2 s-1 and k-MT = (6.9 ± 3.9) × 10-7 m s-1. Therefore, for the first time, we demonstrated that dynamic interfacial tension, which is involved in the electrocapillary effect, can be used to elucidate the kinetics of Eu(III) extraction. We expect that this study will attract the attention of researchers in several fields, including physical and analytical chemistry.

Simultaneous epicardial ablation based on intraoperative electroanatomic mapping during left ventricular assist device implantation.

Intraoperative ventricular tachycardia (VT) ablation targeting the epicardial substrate using three-dimensional electroanatomic mapping (EAM) was performed during left ventricular assist device (LVAD) implantation. We proved that EAM can be safely performed during LVAD implantation and that an ablation strategy based on electrophysiological information may reduce VT recurrence after LVAD implantation.

Validity and reliability of the palliative care needs assessment tool in Japanese patients with heart failure.

AIMS: Although patients with heart failure (HF) frequently experience considerable symptom burden and require significant care, most HF patients do not receive timely intervention due to the absence of a standardized method for identifying those in need of palliative care. The Needs Assessment Tool: Progressive Disease-Heart Failure (NAT: PD-HF) assesses the palliative care needs of patients with HF. However, its validity and reliability have yet to be fully examined. We aimed to assess the validity and reliability of the NAT: PD-HF in Japanese patients with HF. METHODS: We prospectively enrolled 106 consecutive patients with chronic HF admitted to our university hospital between February 2023 and July 2023. Their caregivers (n = 95) and healthcare providers (n = 17) were also included. The NAT: PD-HF was translated from English to Japanese using a forward-backward translation procedure and adapted based on Japanese cultural and medical backgrounds by our professional multidisciplinary team. We assessed the internal consistency of the Japanese NAT: PD-HF version with Cronbach's alpha coefficient and the inter-rater and test-retest reliabilities with Cohen's kappa coefficient. After using the tool, all participants were asked to complete a questionnaire about the tool to determine its validity. RESULTS: The proportion of female patients in this study was 47 (44%). The median age was 72 years [interquartile range (IQR) 59-81]. The median time spent assessing the patients' and their caregivers' needs using the Japanese NAT: PD-HF was 14 min (IQR 12-17). The Cronbach's alpha coefficient was 0.82, and the minimum kappa coefficient was 0.77 for inter-rater reliability and 0.88 for test-retest reliability. In total, 103 patients (97%) and all caregivers responded that the tool was easy to understand. One hundred (94%) patients and 89 (94%) caregivers felt that the tool would improve the quality of care, and 102 (96%) patients and 91 (96%) caregivers indicated that the discussions using this tool allowed them to confide in all their burdens and care needs. All healthcare providers expressed that this tool is helpful in understanding the burden and care needs of both patients and caregivers comprehensively. CONCLUSIONS: The NAT: PD-HF is a reliable and valid tool for Japanese patients with HF and their caregivers. This tool was very well accepted by patients, caregivers and healthcare providers to identify burdens and care needs.

Influence of epicardial adipose tissue inflammation and adipocyte size on postoperative atrial fibrillation in patients after cardiovascular surgery.

Epicardial adipose tissue (EAT) is an active endocrine organ that is closely associated with occurrence of atrial fibrillation (AF). However, the role of EAT in the development of postoperative AF (POAF) remains unclear. We aimed to investigate the association between EAT profile and POAF occurrence in patients who underwent cardiovascular surgery. We obtained EAT samples from 53 patients to evaluate gene expression, histological changes, mitochondrial oxidative phosphorylation (OXPHOS) capacity in the EAT, and protein secretion in EAT-conditioned medium. EAT volume was measured using computed tomography scan. Eighteen patients (34%) experienced POAF within 7 days after surgery. Although no significant difference was observed in EAT profile between patients with and without POAF, logistic regression analysis identified that the mRNA expression levels of tumor necrosis factor-alpha (TNF-α) were positively correlated and adipocyte size in the EAT was inversely correlated with onset of POAF, respectively. Mitochondrial OXPHOS capacity in the EAT was not associated with POAF occurrence; however, it showed an inverse correlation with adipocyte size and a positive correlation with adiponectin secretion. In conclusion, changes in the secretory profile and adipocyte morphology of the EAT, which represent qualitative aspects of the adipose tissue, were present before the onset of AF.

Empagliflozin suppresses mitochondrial reactive oxygen species generation and mitigates the inducibility of atrial fibrillation in diabetic rats.

Introduction: Recent studies have demonstrated that sodium-glucose co-transporter-2 inhibitors (SGLT2-i) reduce the risk of atrial fibrillation (AF) in patients with diabetes mellitus (DM), in which oxidative stress due to increased reactive oxygen species (ROS) contributes to the pathogenesis of AF. We aimed to further investigate this, and examine whether the SGLT2-i empagliflozin suppresses mitochondrial-ROS generation and mitigates fibrosis. Methods: A high-fat diet and low-dose streptozotocin treatment were used to induce type-2 DM (T2DM) in Sprague-Dawley rats. The rats were randomly divided into three groups: control, DM, and DM treated with empagliflozin (30 mg/kg/day) for 8 weeks. The mitochondrial respiratory capacity and ROS generation in the atrial myocardium were measured using a high-resolution respirometer. Oxidative stress markers and protein expression related to mitochondrial biogenesis and dynamics as well as the mitochondrial morphology were examined in the atrial tissue. Additionally, mitochondrial function was examined in H9c2 cardiomyoblasts. Atrial tachyarrhythmia (ATA) inducibility, interatrial conduction time (IACT), and fibrosis were also measured. Results: Inducibility of ATA, fibrosis, and IACT were increased in rats with DM when compared to controls, all of which were restored by empagliflozin treatment. In addition, the rats with DM had increased mitochondrial-ROS with an impaired complex I-linked oxidative phosphorylation capacity. Importantly, empagliflozin seemed to ameliorate these impairments in mitochondrial function. Furthermore, empagliflozin reversed the decrease in phosphorylated AMPK expression and altered protein levels related to mitochondrial biogenesis and dynamics, and increased mitochondrial content. Empagliflozin also improved mitochondrial function in H9c2 cells cultured with high glucose medium. Discussion: These data suggest that empagliflozin has a cardioprotective effect, at least in part, by reducing mitochondrial ROS generation through AMPK signaling pathways in the atrium of diabetic rats. This suggests that empagliflozin might suppress the development of AF in T2DM.