Overall Survival Rates Become Similar Between Percutaneous Ablation and Hepatic Resection With Increasing Age Among Elderly Patients With Early Hepatocellular Carcinoma.

Background: This study aimed to investigate the efficacy and safety of percutaneous ablation versus hepatectomy in an elderly population with hepatocellular carcinoma (HCC).

Methods: Retrospective data on patients aged ≥ 65 years with very-early/early stages of HCC (≤ 50 mm) were obtained from three centers in China. Inverse probability of treatment weighting analysis was performed after stratifying the patients by age (65 - 69, 70 - 74 and ≥ 75 years).

Preventing damage to miniature-loudspeaker by means of dynamic detection of excessive diaphragm displacement.

The rapid development of consumer electronics and the extensive use of mobile devices require the ample use of miniature-loudspeakers for audio applications. The demand for better sound pushes manufacturers to design digital signal processing (DSP) chips (smart amplifiers), which in turn could cause unpleasant sound due to distortion and parameter nonlinearity or transducer damage caused by large diaphragm excursion or voice-coil (VC) burn. This article presents a methodology for nonlinear parameter estimation using an inverse method and displacement limiter for large VC displacement-dependent transducer damage prevention.

Right miniparasternotomy may be a good minimally invasive alternative to full sternotomy for cardiac valve operations: a propensity-adjusted analysis.

Background: Limited real-world data existed for mini-parasternotomy approach with good sample size in Asian cohorts and most previous studies were eclipsed by case heterogeneity. The goal of this study was to compare safety and quality outcomes of cardiac non-coronary valve operations by mini-parasternotomy and full sternotomy approaches on risk-adjusted basis. METHODS From our hospital database, we retrieved the cases of non-coronary valve operations from 1 January 2005 to 31 December 2012, including re-do, emergent, and combined procedures.

Effect of translation and rotation fitting on analysis of corneal topography.

The purpose was to assess the suitability of quadratic equations for the accurate representation of corneal topography and consider the effect of translation and rotation fitting on the quality of fit and the curvature results. Topography images were recorded for the anterior and posterior surfaces of 490 corneas of 490 myopic patients using Pentacam. Elevation data were fitted to four shape models, three of which considered translational and/or rotational fitting.

An inverse method for estimating the electromechanical parameters of moving-coil loudspeakers.

This article presents an inverse method for estimating the electromechanical parameters of a moving-coil loudspeaker with or without the eddy current and suspension creep effects. With known voice-coil displacement, voice-coil current, and stimulus signal as inputs, four calculation procedures for the direct problem, adjoint problem, sensitivity problem, and conjugate gradient method are involved in inversely solving the unknown electromechanical parameters. The proposed method features high efficiency in solving the direct problem through a hybrid spline difference method.

Effects of porous materials in an insert earphone on its frequency response--experiments and simulations.

This article presents a promising approach to customize the sound-pressure response of an insert earphone by delicately tuning the acoustic impedance of porous materials in it. The effects of applying porous materials on and in various parts in the insert earphone were tested experimentally to determine the resulting sound pressure responses. An equivalent circuit model (ECM) is also presented to simulate the sound-pressure-level (SPL) response of the insert earphone.

A simple approximate formula for the physical focal length of spherically focused transducers.

A simple approximate formula is presented to describe the relationship between the physical focal lengths and the geometric focal lengths of spherically focused transducers with ultrasonic fields. This simple expression applies regardless of whether the focus strength is strong or weak, and regardless of whether the fluids are non-attenuating or attenuating. Analysis results show that the average error of the simple approximate formula is certainly less than 2% relative to the numerical solution.