Investigation of the topography-dependent current in conductive AFM and the calibration method

The topography and the electrical properties of materials are two crucial characteristics in determining their functionalities. Conductive atomic force microscopy (CAFM) is widely recognized for its ability to independently measure the topology and conductivity of the sample surface. The increasing trend towards miniaturization in electrical devices and sensors has led to an urgent demand for enhancing the accuracy of CAFM characterization. However, the sample's topography may affect the current measured by CAFM, leading to an inaccurate estimation of the sample's conductivity. Herein, we investigated the existence of topography-dependent current that originates from changes in capacitance between the probe and sample in CAFM testing. A linear correlation between the current and topography has been established using both experimental and theoretical methods. A calibration method based on this linear correlation has been proposed to eliminate the current error induced by the uneven surface of both insulators and conductors. This work will yield substantial advantages for research requiring high-precision CAFM testing.Comment: Corrected typo

Electro-Chemo-Mechanical Properties in Nanostructured Ca-doped Ceria (CDC) by Field Assisted Sintering

Recent investigations have shown that highly oxygen defective cerium oxides generate non-classical electrostriction that is superior to lead-based ferroelectrics. In this work, we report the effect of field-assisted spark plasma sintering (SPS) on electro-chemo-mechanical properties on Ca-doped ceria (CDC). Nanometric powders of ca. 10 nm are rapidly consolidated to form polycrystalline nanostructures with a high degree of crystalline disorder. Remarkably, the resultant material demonstrates a large electromechanical strain without a frequency-related relaxation effect. We conclude that electromechanical activity in CDC materials strictly depends on the Ca-VO interaction, while disorder at the crystalline boundaries has a minor effect

A Health Monitoring System Based on Flexible Triboelectric Sensors for Intelligence Medical Internet of Things and its Applications in Virtual Reality

The Internet of Medical Things (IoMT) is a platform that combines Internet of Things (IoT) technology with medical applications, enabling the realization of precision medicine, intelligent healthcare, and telemedicine in the era of digitalization and intelligence. However, the IoMT faces various challenges, including sustainable power supply, human adaptability of sensors and the intelligence of sensors. In this study, we designed a robust and intelligent IoMT system through the synergistic integration of flexible wearable triboelectric sensors and deep learning-assisted data analytics. We embedded four triboelectric sensors into a wristband to detect and analyze limb movements in patients suffering from Parkinson's Disease (PD). By further integrating deep learning-assisted data analytics, we actualized an intelligent healthcare monitoring system for the surveillance and interaction of PD patients, which includes location/trajectory tracking, heart monitoring and identity recognition. This innovative approach enabled us to accurately capture and scrutinize the subtle movements and fine motor of PD patients, thus providing insightful feedback and comprehensive assessment of the patients conditions. This monitoring system is cost-effective, easily fabricated, highly sensitive, and intelligent, consequently underscores the immense potential of human body sensing technology in a Health 4.0 society

Identification of resection plane for anatomical liver resection using ultrasonography-guided needle insertion

PurposesTo set up an easy-handled and precise delineation of resection plane for hepatic anatomical resection (AR).MethodsCases of AR using ultrasonography-guided needle insertion to trace the target hepatic vein for delineation of resection planes [new technique (NT) group, n = 22] were retrospectively compared with those without implementation of this surgical technique [traditional technique (TT) group, n = 29] in terms of perioperative courses and surgical outcomes.ResultsThe target hepatic vein was successfully exposed in all patients of the NT group, compared with a success rate of 79.3% in the TT group (P < 0.05). The average operation time and intraoperative blood loss were 280 ± 32 min and 550 ± 65 ml, respectively, in the NT group. No blood transfusion was required in either group. The postoperative morbidities (bile leakage and peritoneal effusion) were similar between groups. No mortality within 90 days was observed.ConclusionsUltrasonography-guided needle insertion is a convenient, safe and efficient surgical approach to define a resection plane for conducting AR

Polar Metallocenes

Crystalline polar metallocenes are potentially useful active materials as piezoelectrics, ferroelectrics, and multiferroics. Within density functional theory (DFT), we computed structural properties, energy differences for various phases, molecular configurations, and magnetic states, computed polarizations for different polar crystal structures, and computed dipole moments for the constituent molecules with a Wannier function analysis. Of the systems studied, Mn2(C9H9N)2 is the most promising as a multiferroic material, since the ground state is both polar and ferromagnetic. We found that the predicted crystalline polarizations are 30⁻40% higher than the values that would be obtained from the dipole moments of the isolated constituent molecules, due to the local effects of the self-consistent internal electric field, indicating high polarizabilities

Sufficient and necessary conditions of complete convergence for asymptotically negatively associated random variables

Abstract In this investigation, some sufficient and necessary conditions of the complete convergence for weighted sums of asymptotically negatively associated (ANA, in short) random variables are presented without the assumption of identical distribution. As an application of the main results, the Marcinkiewicz–Zygmund type strong law of large numbers based on weighted sums of ANA cases is obtained. The results of this paper extend and generalize some well-known corresponding ones