An integrated evaluation approach of wearable lower limb exoskeletons for human performance augmentation.

Wearable robots have been growing exponentially during the past years and it is crucial to quantify the performance effectiveness and to convert them into practical benchmarks. Although there exist some common metrics such as metabolic cost, many other characteristics still needs to be presented and demonstrated. In this study, we developed an integrated evaluation (IE) approach of wearable exoskeletons of lower limb focusing on human performance augmentation. We proposed a novel classification of trial tasks closely related to exoskeleton functions, which were divided into three categories, namely, basic trial at the preliminary phase, semi-reality trial at the intermediate phase, and reality trial at the advanced phase. In the present study, the IE approach has been exercised with a subject who wore an active power-assisted knee (APAK) exoskeleton with three types of trial tasks, including walking on a treadmill at a certain angle, walking up and down on three-step stairs, and ascending in 11-storey stairs. Three wearable conditions were carried out in each trial task, i.e. with unpowered exoskeleton, with powered exoskeleton, and without the exoskeleton. Nine performance indicators (PIs) for evaluating performance effectiveness were adopted basing on three aspects of goal-level, task-based kinematics, and human-robot interactions. Results indicated that compared with other conditions, the powered APAK exoskeleton make generally lesser heart rate (HR), Metabolic equivalent (METs), biceps femoris (BF) and rectus femoris (RF) muscles activation of the subject at the preliminary phase and intermediate phase, however, with minimal performance augmentation at advanced phase, suggesting that the APAK exoskeleton is not suitable for marketing and should be further improved. In the future, continuous iterative optimization for the IE approach may help the robot community to attain a comprehensive benchmarking methodology for robot-assisted locomotion more efficiently.

Fluorometholone inhibits high glucose-induced cellular senescence in human retinal endothelial cells.

Diabetic retinopathy (DR) is a common diabetic complication that severely impacts the life quality of diabetic patients. Recently, cellular senescence in human retinal endothelial cells (HRECs) induced by high glucose has been linked to the pathogenesis of DR. Fluorometholone (FML) is a glucocorticoid drug applied in the treatment of inflammatory and allergic disorders of the eye. The objective of the present study is to investigate the protective function of FML on high glucose-induced cellular senescence in HRECs. The in vitro injury model was established by stimulating HRECs with 30 mm glucose. After evaluating the cytotoxicity of FML in HRECs, 0.05% and 0.1% FML were used as the optimal concentration in the entire experiment. It was found that the excessive released inflammatory factors including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8) in HRECs induced by high glucose were significantly suppressed by FML, accompanied by the inhibitory effects on the expression levels of vascular endothelial growth factor (VEGF) and tissue factor (TF). Declined telomerase activity and enhanced senescence-associated ß-galactosidase (SA-ß-gal) activity were found in high glucose-challenged HRECs, which were dramatically alleviated by FML, accompanied by the inactivation of the p53/p21 and retinoblastoma (Rb) signaling. Interestingly, FML ameliorated high glucose-induced dephosphorylation of Akt. Lastly, the protective effects of FML against high glucose-induced cellular senescence in HRECs were abolished by the co-treatment of the PI3K/Akt signaling inhibitor LY294002, suggesting the involvement of this pathway. Taken together, these data revealed that FML-inhibited high glucose-induced cellular senescence mediated by Akt in HERCs, suggesting a novel molecular mechanism of FML.

A new xanthyletin-type coumarin from the roots of Peucedanum praeruptorum.

A new xanthyletin-type coumarin, neopeucedalactone (1), was isolated from the roots of Peucedanum praeruptorum Dunn. Its chemical structure was elucidated based on extensive spectroscopic interpretation. The absolute configurations of xanthyletin-type coumarin were determined by comparing experimental and calculated ECD spectra for the first time. Compound 1 exhibited moderate cell growth inhibitory activities in vitro against human leukemic HL-60, THP-1 cell lines, and human prostate cancer PC-3 cell lines, with IC50 values of 9.97, 27.80, and 48.68 µM, respectively. [Formula: see text].