Effect of dialyzer membranes on mortality in uremic patients undergoing long-term hemodialysis: A Nationwide population-based study using the Taiwan Dialysis Registry Data System 2005-2012.

The characteristics in dialyzer are associated with mortality in patients with end-stage renal disease (ESRD) receiving hemodialysis (HD). This study is to investigate the effects of dialyzer membranes on 3-year mortality in ESRD patients. From the long-term nationwide population database. Prevalent HD patients during 2005-2012 were enrolled. Our main analysis to calculate the effect was cox regression multivariate model. Overall, the mean age of all population (N = 73 565) was 61.0 ± 13.6 years, the observation period is 2.46 years ±0.98 within 3 years and 64.6% used polysulfone (PS), polymethyl methacrylate (PMMA) (11.6%), polyethersulfone (11.4%), and cellulose triacetate (CTA) (10.7%), ethylene vinyl alcohol (EVAL) (hazard ratio [HR] 2.72, 95% confidence interval [CI] 1.71-4.33) and CTA (HR 1.35, 95% CI 1.12-1.64) were associated with higher mortality than PS, but PMMA was not. EVAL and CTA adversely affected mortality and PMMA had no protective role. Further investigations on membrane characters on HD patients are warranted. Taipei Medical University (TMU) (TMU-JIRB (No. N201804051).

Closed-Loop Torque and Kinematic Control of a Hybrid Lower-Limb Exoskeleton for Treadmill Walking.

Restoring and improving the ability to walk is a top priority for individuals with movement impairments due to neurological injuries. Powered exoskeletons coupled with functional electrical stimulation (FES), called hybrid exoskeletons, exploit the benefits of activating muscles and robotic assistance for locomotion. In this paper, a cable-driven lower-limb exoskeleton is integrated with FES for treadmill walking at a constant speed. A nonlinear robust controller is used to activate the quadriceps and hamstrings muscle groups via FES to achieve kinematic tracking about the knee joint. Moreover, electric motors adjust the knee joint stiffness throughout the gait cycle using an integral torque feedback controller. For the hip joint, a robust sliding-mode controller is developed to achieve kinematic tracking using electric motors. The human-exoskeleton dynamic model is derived using Lagrangian dynamics and incorporates phase-dependent switching to capture the effects of transitioning from the stance to the swing phase, and vice versa. Moreover, low-level control input switching is used to activate individual muscles and motors to achieve flexion and extension about the hip and knee joints. A Lyapunov-based stability analysis is developed to ensure exponential tracking of the kinematic and torque closed-loop error systems, while guaranteeing that the control input signals remain bounded. The developed controllers were tested in real-time walking experiments on a treadmill in three able-bodied individuals at two gait speeds. The experimental results demonstrate the feasibility of coupling a cable-driven exoskeleton with FES for treadmill walking using a switching-based control strategy and exploiting both kinematic and force feedback.

Digital holographic microtomography for high-resolution refractive index mapping of live cells.

Quantification of three-dimensional (3D) refractive index (RI) with sub-cellular resolution is achieved by digital holographic microtomography (DHµT) using quantitative phase images measured at multiple illumination angles. The DHµT system achieves sensitive and fast phase measurements based on iterative phase extraction algorithm and asynchronous phase shifting interferometry without any phase monitoring or active control mechanism. A reconstruction algorithm, optical diffraction tomography with projection on convex sets and total variation minimization, is implemented to substantially reduce the number of angular scattered fields needed for reconstruction without sacrificing the accuracy and quality of the reconstructed 3D RI distribution. Tomogram of a living CA9-22 cell is presented to demonstrate the performance of the method. Further, a statistical analysis of the average RI of the nucleoli, the nucleus excluding the nucleoli and the cytoplasm of twenty CA9-22 cells is performed.