Vibration of a Liquid Crystal Elastomer Spring Oscillator under Periodic Electrothermal Drive.

The oscillations of electrically actuated thermally-responsive liquid crystal elastomer (LCE) microfibers under cyclic electric actuation have been discovered in recent experiments. Periodic electric actuation is a common method of active control with potential applications in the fields of micro-actuators. In this paper, the vibration behavior of LCE spring oscillator under periodic electrothermal drive is studied theoretically. Based on the dynamic LCE model, the dynamic governing equation of the LCE spring oscillator is established, and the time history curves of the vibration are obtained by numerical calculations. The results show that the periodic electrothermal drive can cause periodic vibration of the LCE spring oscillator. With the increase of time rate, the vibration amplitude increases first and then decreases. In a small damping system, there exist optimal sets of electrothermal drive period and electrothermal drive time rate to maximize the system amplitude. For the optimum periodic mode, the vibration amplitude of the spring oscillator is affected by the current heat, damping coefficient, gravital acceleration, spring constant and shrinkage coefficient, but not by the initial velocity. The application examples of LCE materials show that periodic electrothermally driven LCEs have promising applications. The results of this study are instructive for the design of soft robots and LCE-based electric locomotives.

Effect of gonadotropins and endometrial thickness on pregnancy outcome in patients with unexplained infertility or polycystic ovarian syndrome undergoing intrauterine insemination.

OBJECTIVE: The purpose of this study was to investigate the effect of gonadotropin dose and endometrial thickness (EMT) on pregnancy outcome in patients undergoing intrauterine insemination (IUI). METHODS: We retrospectively analyzed data from 361 patients with unexplained infertility or polycystic ovarian syndrome (PCOS) who underwent 930 IUI cycles treated with gonadotropins. Then, we measured the effects of gonadotropins and EMT on the clinical pregnancy rate. Finally, we assessed the association of various doses of gonadotropins on EMT. RESULTS: The dose of gonadotropins given and thickness of the endometrium were higher in the pregnancy group than in the nonpregnancy group (636.0 vs. 600.0 IU for gonadotropin dose; 9.15 vs. 8.70 mm for EMT). Clinical pregnancy rates were significantly improved by increasing the dose of gonadotropins (9.1%, <450 IU; 16.2%, 450-599 IU; 18.6%, 600-749 IU, and 17.3%, ≥750 IU), or by increased EMT (0%, <5.0 mm; 12.2%, 5.0-6.9 mm; 15.5%, 7.0-14.0 mm; and 33.3%, >14.0 mm). CONCLUSION: Increasing the dose of gonadotropins to stimulate one follicle to develop may benefit endometrial proliferation and improve IUI outcomes.

Role of Anesthesia Nurses in the Treatment and Management of Patients With COVID-19.

As the backbone for the treatment of patients with coronavirus disease 2019 (COVID-19), nurses have been playing key roles in cabin hospitals, isolation wards, and intensive care units for critical cases. Anesthesia nurses have their own professional specialties, such as airway management, the use and maintenance of life support equipment, including ventilators, and the use of high-flow oxygen equipment. With rich experience in emergency responses and nursing, anesthesia nurses, along with emergency nurses and critical care nurses, play important roles during the treatment of patients with COVID-19. In our hospital, 27 of 34 anesthesia nurses participated in the front-line fight against COVID-19 and did an excellent job. Anesthesia care by nurses is relatively new in China, and the role of anesthesia nurses during a disaster response has not been fully appreciated. Given their specialty, anesthesia nurses have played important roles in the treatment of patients with COVID-19. We hope that authorities will consider including anesthesia nurses in national disaster response medical rescue teams.