Tian Li

© 2014 American Chemical Society.Attempts to apply artificial nano/micromotors for diverse biomedical applications have inspired a variety of strategies for designing motors with diverse propulsion mechanisms and functions. However, existing artificial motors are made exclusively of synthetic materials, which are subject to serious immune attack and clearance upon entering the bloodstream. Herein we report an elegant approach that turns natural red blood cells into functional micromotors with the aid of ultrasound propulsion and magnetic guidance. Iron oxide nanoparticles are loaded into the RBCs, where their asymmetric distribution within the cells results in a net magnetization, thus enabling magnetic alignment and guidance under acoustic propulsion. The RBC motors display efficient guided and prolonged propulsion in various biological fluids, including undiluted whole blood. The stability and functionality of the RBC motors, as well as the tolerability of regular RBCs to the ultrasound operation, are carefully examined. Since the RBC motors preserve the biological and structural features of regular RBCs, these motors possess a wide range of antigenic, transport, and mechanical properties that common synthetic motors cannot achieve and thus hold considerable promise for a number of practical biomedical uses.

Using Bakhtin's notion of polyphony, this study explored the discussion of the end-of-life issues in the Course on Life and Death Education in one Chinese university. Ethnographic methods were adopted to investigate the collision between the classroom voices and the voices of the mainstream culture on end-of-life in the process of developing students' attitudes toward death. The findings revealed that “to understand death” involved challenging the voice of “strangeness and fear of death”; “honestly facing up to and accepting the feelings of the fear, pain, and helplessness” was the response to “be brave”; and the goal “to die peacefully” resisted the notion of “extending life at any cost.” Through the collision between these voices, students developed their attitudes toward death in facing, understanding, accepting, and choosing how to die. The analysis further revealed that providing only one “answer” to death by the teacher is not sufficient or effective to foster students' attitudes toward death because the students are a diverse group holding different views on the end-of-life issues, which demonstrated the importance of creating dialogues in the life and death education.

There is considerable evidence that the experience of justice is associated with perceived legitimacy of authority, but there has been no research about this association when considering past rather than current fairness. Based on the fairness heuristic theory, we tested the hypothesis that interpersonal justice trajectories positively affect perceived legitimacy of the authority; we also tested whether social class moderated this effect. Community residents rated the authority's fairness on 16 consecutive weeks and rated perceived legitimacy on the 16th week. The results of latent growth modeling showed that the trajectory of interpersonal justice scores leading up to the final week significantly predicted perceived legitimacy, regardless of the current experience of interpersonal fairness. Tests of moderation showed that the legitimacy perceptions of individuals of lower subjective social class were significantly affected by interpersonal justice trajectories, whereas this was not the case among individuals of higher subjective social class. The results are discussed in terms of their implications for research on perceived legitimacy and justice, as well as their implications for understanding social class.