RESUMEN
Ti3C2Tx (a typical MXene) has been widely used in light-driven actuators due to its outstanding photothermal conversion capability. However, the response speed of these actuators is always slow because the effective irradiated area is limited to their surface. Herein, we propose a wood-based composite material which is made by coating Ti3C2Tx on delignified wood (DW). The high porosity of DW leads to high loading of Ti3C2Tx and provides large irradiated areas, thus enhancing photothermal conversion efficiency. The delignification on wood can expose cellulose with highly hydrophilic surface for rapid diffusion of Ti3C2Tx suspension, and the hydroxy in cellulose can act as binding sites to form stable combination with Ti3C2Tx. Taking advantage of the good compressibility of DW, a simple densification is conducted on TDW (Ti3C2Tx/DW) to greatly shorten the distance between adjacent oxygen-enriched Ti3C2Tx nanosheets, enhancing the conjugation among nanosheets, thus endowing TDW with good flexibility and high heat transfer efficiency. Moreover, we manufacture a light-driven bilayer actuator comprised of TDW as the passive layer and low-density polyethylene (LDPE) as the active layer. Our light-driven actuator exhibits a tremendous angle variation of 160° at a light intensity of 120 mW/cm2. A series of devices based on the TDW/LDPE actuator are demonstrated, including simulated gestures, a four-finger soft gripper, and a bionic flower. Moreover, we propose a light-controlled smart switch which can be used on non-contact (COVID-19) or dangerous (blasting) occasions. Additionally, we present a finite element simulation to predict the bending deformation, which guides the accurate control of the devices.
RESUMEN
Background The long-term functional outcome of discharged patients with coronavirus disease 2019 (COVID-19) remains unresolved. We aimed to describe a six-month follow-up of functional status of COVID-19 survivors.Methods We reviewed the data of COVID-19 patients who had been consecutively admitted to the Tumor Center of Union Hospital (Wuhan, China) between 15 February and 14 March 2020. We quantified a six-month functional outcome reflecting symptoms and disability in COVID-19 survivors using a post-COVID-19 functional status scale ranging from 0 to 5 (PCFS). We examined the risk factors for the incomplete functional status defined as a PCFS > 0 at a six-month follow-up after discharge.Results We included a total of 95 COVID-19 survivors with a median age of 62 (IQR 53-69) who had a complete functional status (PCFS grade 0) at baseline in this retrospective observational study. At six-month follow-up, 67 (70.5%) patients had a complete functional outcome (grade 0), 9 (9.5%) had a negligible limited function (grade 1), 12 (12.6%) had a mild limited function (grade 2), 7 (7.4%) had moderate limited function (grade 3). Univariable logistic regression analysis showed a significant association between the onset symptoms of muscle or joint pain and an increased risk of incomplete function (unadjusted OR 4.06, 95%CI 1.33 - 12.37). This association remained after adjustment for age and admission delay (adjusted OR 3.39, 95%CI 1.06 - 10.81, p = 0.039).Conclusions A small proportion of discharged COVID-19 patients may have an incomplete functional outcome at a six-month follow-up; intervention strategies are required.