Twisted loxodromes in spindle-shaped polymer nematics.

We develop an energetic model that captures the twisting behavior of spindle-shaped polymer microparticles with nematic ordering, which display remarkably different twisting behavior to ordinary nematics confined to spindles. We have previously developed a geometric model of the twisting, based on experimental observations, in which we showed that the twist pattern follows loxodrome spirals [Ansell, et al., Phys. Rev. Lett., 2019, 123, 157801]. In this study, we first consider a spindle-shaped surface and show that the loxodrome twisting behavior of our system can be captured by the Frank free energy of the nematic with an additional term constraining the length of the integral curves of the system. We then extend the ideas of this model to the bulk and explore the parameter space for which the twisted loxodrome solution is energetically favorable.

Threading the Spindle: A Geometric Study of Chiral Liquid Crystal Polymer Microparticles.

Polymeric particles are strong candidates for designing artificial materials capable of emulating the complex twisting-based functionality observed in biological systems. In this Letter, we provide the first detailed investigation of the swelling behavior of bipolar polymer liquid crystalline microparticles. Deswelling from the spherical bipolar configuration causes the microparticles to contract anisotropically and twist in the process, resulting in a twisted spindle-shaped structure. We propose a model to describe the observed spiral patterns and twisting behavior.

Technology and the issues facing nursing assessment.

This article describes an investigation into the use of technology and the issues nurses face undertaking nursing assessment. It reports qualitative, descriptive research involving interviews with ten ward nurses from three hospitals in New Zealand. Thematic analysis of the data revealed three key issues: the impact of technology, the influence of early warning systems and nurse autonomy. Results show how clinical decision making around nursing assessment is influenced by technology and the Early Warning Score. These clinical decisions may not always be informed by critical thinking in complex healthcare environments. The article concludes that nurse autonomy, while supported and endorsed in theory, is frequently in conflict with hospital risk-management policies and the use of prescriptive algorithms.

Why don't nurses consistently take patient respiratory rates?

This is an investigation into nurses' practice of when they would not take and record a patient's respiratory rate. It reports results of qualitative, descriptive research involving interviews with ten ward nurses from three hospitals in New Zealand. Results affirm that, despite it being the most sensitive vital sign for managing patients, nurses acknowledged circumstances in which respiratory rate taking was missed. Reasons were complex and, contrary to expectations, not always associated with the introduction of technology to record other vital signs. Time pressures, work interruptions and rationalised judgements made by experienced nurses all contributed to incidences of missed respiratory rate taking. It is concluded that patient respiratory rate measures do not seem to be highly valued, calling into questions nurses' level of understanding of respiratory physiology, as well as the extent to which intuitive nursing practice is supported by critical analysis.