AFM In Liquid: A High Sensitivity Study On Biological Membranes

Frequency Modulation AFM (FM-AFM) is commonly operated in ultra-high vacuum, though its inception in liquids for biological samples is relatively new. Here, we highlight the ability of FM-AFM to perform molecular resolution imaging of biomembrane surfaces and to detect individual layers of structured water at similar membrane interfaces. These studies highlight the potential of FM-AFM for studying model membranes and lipid raft systems on the molecular scale

Direct Imaging Of Lipid-Ion Network Formation Under Physiological Conditions By Frequency Modulation Atomic Force Microscopy

Various metal cations in physiological solutions interact with lipid headgroups in biological membranes, having an impact on their structure and stability, yet little is known about the molecular-scale dynamics of the lipid-ion interactions. Here we directly investigate the extensive lipid-ion interaction networks and their transient formation between headgroups in a dipalmitoylphosphatidylcholine bilayer under physiological conditions. The spatial distribution of ion occupancy is imaged in real space by frequency modulation atomic force microscopy with sub-Angstrom resolution

Quantitative Force Measurements In Liquid Using Frequency Modulation Atomic Force Microscopy

The measurement of short-range forces with the atomic force microscope (AFM) typically requires implementation of dynamic techniques to maintain sensitivity and stability. While frequency modulation atomic force microscopy (FM-AFM) is used widely for high-resolution imaging and quantitative force measurements in vacuum, quantitative force measurements using FM-AFM in liquids have proven elusive. Here we demonstrate that the formalism derived for operation in vacuum can also be used in liquids, provided certain modifications are implemented. To facilitate comparison with previous measurements taken using surface forces apparatus, we choose a model system (octamethylcyclotetrasiloxane) that is known to exhibit short-ranged structural ordering when confined between two surfaces. Force measurements obtained are found to be in excellent agreement with previously reported results. This study therefore establishes FM-AFM as a powerful tool for the quantitative measurement of forces in liquid

Additional file 3 of Experienced based co design: nursing preceptorship educational programme

Additional file 3. GRIPP2 PPI reporting Checklist

Additional file 1 of Experienced based co design: nursing preceptorship educational programme

Additional file 1. Semi structured Interview Guide

Key tips to providing a psychologically safe learning environment in the clinical setting

Having psychological safety embedded in preceptorship relationships facilitates positive interpersonal and educational experiences for students. Psychological safety refers to a student's belief as to whether or not it is safe for them to take interpersonal risks, such as asking questions, sharing an idea for improvement or speaking up to maintain patient safety. Having psychological safety leads to collaboration, positive student learning experiences and effective patient care. This article presents key guidelines for preceptors to provide a psychologically safe learning environment for their students. Guidelines fall under four categories 1) before meeting students, 2) first meeting students, 3) continued relationship with students, and 4) general rules. These guidelines are informed by current literature on psychological safety and preceptorship and the author's clinical expertise in nursing preceptorship. We conceptualise psychological safety in a nursing preceptorship for preceptors to denote the experience of inclusivity, empowerment, and well-being of students within the social, cultural and physical clinical learning environment. A crucial attribute to cultivating a psychologically safe environment involves being an accessible and approachable preceptor. </p

Additional file 2 of Experienced based co design: nursing preceptorship educational programme

Additional file 2. Student, Preceptor & Patient Touchpoints and overarching target behaviours to include in educational programme

High viscosity environments: an unexpected route to obtain true atomic resolution with atomic force microscopy

Atomic force microscopy (AFM) is widely used in liquid environments, where true atomic resolution at the solid–liquid interface can now be routinely achieved. It is generally expected that AFM operation in more viscous environments results in an increased noise contribution from the thermal motion of the cantilever, thereby reducing the signal-to-noise ratio (SNR). Thus, viscous fluids such as ionic and organic liquids have been generally avoided for high-resolution AFM studies despite their relevance to, e.g. energy applications. Here, we investigate the thermal noise limitations of dynamic AFM operation in both low and high viscosity environments theoretically, deriving expressions for the amplitude, phase and frequency noise resulting from the thermal motion of the cantilever, thereby defining the performance limits of amplitude modulation, phase modulation and frequency modulation AFM. We show that the assumption of a reduced SNR in viscous environments is not inherent to the technique and demonstrate that SNR values comparable to ultra-high vacuum systems can be obtained in high viscosity environments under certain conditions. Finally, we have obtained true atomic resolution images of highly ordered pyrolytic graphite and mica surfaces, thus revealing the potential of high-resolution imaging in high viscosity environments.Irish Research Council for Science, Engineering and TechnologyScience Foundation IrelandAlexander von Humboldt FoundationProgramme for Research in Third Level Institutions Cycle 5European Regional Development Fun