Magnetic-acoustic actuated spinous microrobot for enhanced degradation of organic pollutants.

A growing interest in the development of efficient strategies for the removal of organic pollutants from polluted water is emerging. As such, artificial micro/nano machines performing excellent water purification tasks have recently attracted more research attention of scientists. Hereby a spinous Fe3O4@PPy microrobot is presented that towards an efficient organic pollutant removal by enhancing Fenton-like reaction. The microrobot is fabricated by wrapping polypyrrole (PPy) on a spiny magnetic template prepared from sunflowers pollen. Modulating the sound pressure and frequency of the ultrasonic field enables the Fe3O4@PPy microrobot to present multimode motion, such as violent eruption-like motion caused by local cavitation (ELM), march-like unific motion (MLM), and typhoon-like rotation toward the center gathered motion (TLM). This multimode motion achieves the sufficient locomotion of microrobots in three-dimensional space and effective contact with organic pollutants in polluted water. Furthermore, a 5.2-fold increase in the degradation rate of methylene blue has been realized using Fe3O4@PPy microrobots under low-concentration hydrogen peroxide conditions. Also, the magnetically controlled recovery of microrobots from water after the completion of the degradation task has been demonstrated. The magnetic-acoustic actuated spinous microrobot can be extrapolated to other catalytic microrobot, developing a new strategy for an easier implementation and recovery of microrobot in real applications of water purification.

Incidence and risk factors for postoperative nosocomial pneumonia in elderly patients with hip fractures: A single-center study.

Objective: Postoperative nosocomial pneumonia is a terrible complication, especially for elderly patients. This study attempts to investigate the incidence and risk factors for postoperative nosocomial pneumonia and its influence on hospitalization stay in elderly patients with hip fractures. Methods: This study retrospectively retrieved hospitalization records of patients who presented a hip fracture and underwent surgeries in our institution between January 2014 and December 2021. Postoperative new-onset pneumonia was determined in accordance with discharge diagnosis. Multivariate logistic regression analysis was performed to identify the associated risk factors with pneumonia, and its influence on total hospitalization stay or postoperative hospitalization stay was investigated by multivariate linear regression analyses. Results: Totally, 808 patients were included, among whom 54 developed a pneumonia representing the incidence rate of 6.7% (95% CI, 5.0%-8.4%). Six factors were identified as independently associated with pneumonia, including advanced age (OR, 1.50 for each 10-year increment), history of chronic respiratory disease (OR, 4.61), preoperative DVT (OR, 3.51), preoperative delay to operation (OR, 1.07 for each day), surgical duration ≥120 min (OR, 4.03) and arthroplasty procedure (OR, 4,39). When adjusted for above confounders, pneumonia was significantly positively associated with total hospitalization stay (standardized coefficient, 0.110; p < 0.001) and postoperative hospitalization stay (standardized coefficient, 0.139; p < 0.001). Conclusions: This study identified multiple factors associated with postoperative pneumonia and its influence on prolonging hospitalization stay, which would facilitate preventive targeted intervention into implementation for individuals with different risk profiles.