Two-dimensional speckle tracking imaging analyses of the correlations between left atrial appendage function and stroke risk in nonvalvular atrial fibrillation patients.

Stroke incidence is the most severe complication associated with atrial fibrillation (AF), and the most common site of thrombus formation in AF patients is the left atrial appendage (LAA). This study was developed to use two-dimensional speckle tracking imaging (2D-STI) to explore associations between LAA strain/strain rate and stroke incidence and to evaluate the value of utilizing LAA strain and strain rate values to support the stratification of nonvalvular AF (NVAF) patients based on stroke risk. A total of 486 AF patients who had undergone transesophageal echocardiography to exclude potential intracardiac thrombosis between March 2021 and November 2022 were consecutively enrolled. Patients meeting the inclusion criteria were separated into two groups according to their history of stroke/transient ischemic attack (TIA). LAA strain and strain rate values in these patients were measured via 2D-STI. Multivariable logistic regression analysis was employed to determine independent risk factors for the construction of a combined predictive model. Of the 333 analyzed patients (134 females, aged 65 (56,72) years), 39 (11.71%, 39/333) had a history of stroke at the time of evaluation. Multivariate logistic regression analysis demonstrated that nonparoxysmal AF, CHA2DS2VASc score, LAA thrombus/spontaneous echo contrast (SEC), LAA strain, and strain rate were all predictors of stroke incidence among NVAF patients. The combined predictive model demonstrated excellent discriminative ability, with an AUC of 0.91 (95%CI 0.87-0.95, P < 0.001), and a sensitivity and specificity of 79.49% and 89.46%, respectively. The Hosmer-Lemeshow test confirmed good calibration, yielding a value of 0.98. Comparative decision curve analysis showed that the model provided superior net benefits compared to the CHA2DS2VASc score. Furthermore, the model exhibited improved predictive performance and reclassification for stroke when compared to the CHA2DS2VASc score (AUC 0.91 vs. 0.88, Z = 2.32, P = 0.02), accompanied by a significant increase in the net reclassification index (+ 5.44%, P < 0.001) and integrated discrimination improvement (8.21%, P < 0.001). These data demonstrate that LAA strain and strain rate, as measured via 2D-STI, can offer value when assessing LAA function in AF patients, potentially providing further predictive value to extant clinical risk scoring strategies.

Ti3C2 MXene-derived Li4Ti5O12 nanoplates with in-situ formed carbon quantum dots for metal-ion battery anodes.

Two-dimensional (2D) material Ti3C2 MXenes have recently been used in electrode composites for lithium-ion batteries (LIBs) for their excellent electrical conductivity and accordion-like nanosheet morphology. However, Ti3C2 has low specific capacity and fast degradation rate upon cycling after inevitably coupling with surface species during synthesis. In this work, Ti3C2 is used as Ti-source for Li4Ti5O12 (LTO) and C-source for carbon quantum dots (CQDs) in a one-step hydrothermal process. The resultant LTO product (M-LTO) inherits the nanosheet morphology of Ti3C2 with uniformly anchored CQDs. The highly electronic conductive CQDs optimize the transmission path of ions which reduces the diffusion barrier of ions, and they further increase the density of states of the material which effectively improving the conductivity of M-LTO. Remarkable electrochemical performances including high initial specific capacity, long lifetime and excellent low temperature capacity are demonstrated for this type of electrode in LIBs, sodium ion batteries (SIBs) and lithium-magnesium ion hybrid batteries (LMIHBs). This paper offers a new strategy to the rapidly expanding research on the application of transition metal MXenes in electrodes for metal-ion batteries.

Sodium storage mechanism of a GeP5/C composite as a high capacity anode material for sodium-ion batteries.

The sodium storage mechanism of a GeP5/C composite electrode was revealed. Metallic Ge formed during discharge enhances the electronic conductivity of the electrode, while NaxP mitigates the agglomeration and volume change of Ge in the alloying process. The GeP5 phase is regenerated after recharge along with elemental Ge and P, implying a reversible phase transition of GeP5 during cycling.

A Fuzzy Comprehensive CS-SVR Model-based health status evaluation of radar.

The purpose of Fuzzy Comprehensive CS-SVR Model (FCCS-SVR) is to evaluate and monitor the health status of a radar equipment and then keep its safe operation. Due to reasons such as few samples, slow changes and the nonlinear structure of data of fault monitoring signal, the health status evaluation of a radar system is quite difficult. By establishing the evaluation index system of a radar, the combination of AHP method and Entropy weight method is studied in this paper. In order to evaluate the value of health status, several optimization algorithms including PSO, GA, BA and CS are used for optimizing the parameters of SVR model. Meanwhile, in order to avoid the problem that the system is at the edge of the state, a radar health assessment method based on the combination of Fuzzy Comprehensive Evaluation and Cuckoo Search-Support Vector Regression (CS-SVR), which is named as Fuzzy Comprehensive CS-SVR (FCCS-SVR), is further proposed. The result of case analysis reflects that the state evaluation of the radar system is realized. The system performance analysis shows that the use of FCCS-SVR evaluation method provides a high recognition rate and can accurately assess the health status of the radar system.

Synergistic effects of ultrasound-targeted microbubble destruction and TAT peptide on gene transfection: an experimental study in vitro and in vivo.

Cell-permeable peptides (CPPs) and ultrasound-targeted microbubble destruction (UTMD) have tremendous potential for gene delivery. However, their applications are limited due to nonspecificity of CPPs and low transfection efficiency of UTMD. Here, we developed a 'smart' gene delivery system by encapsulating TAT peptide (TATp) and hepatocyte growth factor (HGF) gene within lipid microbubbles, in which TATp was protected from being enzymatically cleaved and HGF gene was protected from degradation. This new strategy had synergistic effects of UTMD and TATp on gene transfection. We investigated the efficacy and safety of HGF gene transfection mediated by the combination of UTMD and TATp in vitro and in vivo. The results from MTT assay and flow cytometry analyses indicated that the combination of UTMD and TATp could enhance HGF gene expression in HUVECs without any significant side effect on cell viability. In rat myocardial infarction models, we demonstrated that the protein and mRNA expressions of HGF in myocardium caused by the combination of UTMD and TATp were the highest. Histopathological findings demonstrated that the combination of UTMD and TATp enhanced myocardial microvasculature and ameliorated myocardial fibrosis. In conclusion, the combination of UTMD and TATp might be a safe and efficient technique for gene delivery.