Effect of Transcranial Direct Current Stimulation on Endurance Performance in Elite Female Rowers: A Pilot, Single-Blinded Study

Endurance, which is dependent at least partly upon the activation of the brain cortex, is important for performance in rowing. Transcranial direct current stimulation (tDCS) has shown benefits for endurance, but its effects on the endurance performance of elite rowing athletes are unknown, and are examined in this study. Eight elite female rowers completed 5 km of rowing on an ergometer following stimulation of the tDCS and sham over motor cortices. Each session lasted 20 min and the current was set at 2.2 mA. Time, 500 m/split, power, time corresponding to 500 m (TC500) and power corresponding to 500 m (PC500) were recorded continuously throughout the tests. No significant differences in time, 500 m/split and power were observed between baseline, tDCS and sham. Compared to the sham, tDCS induced a percentage reduction in TC500 from baseline to 2500 m and 4000 m, and a percentage increase in PC500 from baseline to 500 m, 1000 m, 1500 m, 2000 m, 2500 m, 4000 m, 4500 m and 5000 m. One-session tDCS did not have significant benefits for rowing endurance performance in elite professional rowers, and had only marginally greater efficacy compared to sham. These findings offer knowledge helpful to the design of future studies exploring the effects of tDCS on the endurance performance of elite rowers

Research Progress on Establishing and Evaluation of Acne Animal Models

According to understanding of the pathogenesis of acne, scholars have established animal models of acne inflammation, animal models of grafting human skin acne, and natural acne animal models. The acne inflammation model is mainly induced by bacterial infection, chemical drug application, and foreign matter injection. Natural acne animal models include animals that some are sensitivity to hormones and some have clinical symptoms of acne. It is necessary to select appropriate model animals and replicate model methods for the development of acne intervention products with different degrees and mechanisms. At present, there are only human evaluation standards of acne health functions in China, but no animal evaluation standards, which has affected the in-depth study of the pathogenesis of acne as well as the research and development progress of acne products. This article summarizes the conditions for the occurrence of acne, the characteristics of human skin, the bidirectional effect of Cutibacterium acnes on human skin, acne animal models, and commonly used observation and evaluation indicators, providing the reference for studying the pathogenesis of acne, promoting acne treatment and health care, and developing treatment products

A novel state-of-charge estimation method of lithium-ion batteries combining the Grey model and Genetic Algorithms

In order to guarantee safe and reliable operation of battery in electric vehicles and utilizing capacity at the greatest extent, it is indispensable to estimate the state-of-charge (SoC) of battery. This study aimed to develop such a novel estimation approach based on the Grey model and Genetic Algorithms method without the need of a high computation cost and high-fidelity battery model. A SoC analytical model was established using the Grey System theory based on a limited amount of incomplete data compared to conventional methods. The model was further improved by applying the sliding window mechanism to adjust the model parameters according to the evolving operating status and conditions. In addition, the Genetic Algorithms were introduced to achieve an optimal adjustment coefficient, $\lambda$ , in the traditional Grey model (1, 1) model to further improve the source estimation accuracy. For experimental verification, two types of Lithium-ion batteries were used as the device-under-test, and the accuracy and repeatability of the proposed modeling method were verified under a range of battery discharging conditions. The results indicate that the proposed modeling approach features a higher accuracy for such systems compared to the benchmarking GM method that is illustrated using typical passenger car driving cycles