Mechanical DNA Origami to Investigate Biological Systems.

The ability to self-assemble DNA nanodevices with programmed structural dynamics that can sense and respond to the local environment can enable transformative applications in fields including mechanobiology and nanomedicine. The responsive function of biomolecules is often driven by alterations in conformational distributions mediated by highly sensitive interactions with the local environment. In this review, the current state-of-the-art in constructing complex DNA geometries with dynamic and mechanical properties to enable a molecular scale force measurement is first summarized. Next, an overview of engineering modular DNA devices that interact with cell surfaces is highlighted detailing examples of mechanosensitive proteins and the force-induced dynamic molecular interaction on the downstream biochemical signaling. Finally, the challenges and an outlook on this promising class of DNA devices acting as nanomachines to operate at a low piconewton range suitable for a majority of biological effects or as hybrid materials to achieve higher tension exertion required for other biological investigations, are discussed.

Isothermal self-assembly of multicomponent and evolutive DNA nanostructures.

Thermal annealing is usually needed to direct the assembly of multiple complementary DNA strands into desired entities. We show that, with a magnesium-free buffer containing NaCl, complex cocktails of DNA strands and proteins can self-assemble isothermally, at room or physiological temperature, into user-defined nanostructures, such as DNA origamis, single-stranded tile assemblies and nanogrids. In situ, time-resolved observation reveals that this self-assembly is thermodynamically controlled, proceeds through multiple folding pathways and leads to highly reconfigurable nanostructures. It allows a given system to self-select its most stable shape in a large pool of competitive DNA strands. Strikingly, upon the appearance of a new energy minimum, DNA origamis isothermally shift from one initially stable shape to a radically different one, by massive exchange of their constitutive staple strands. This method expands the repertoire of shapes and functions attainable by isothermal self-assembly and creates a basis for adaptive nanomachines and nanostructure discovery by evolution.

Interprofessional Collaborative Clinical Practice in Medicine and Pharmacy: Measure of Student Perceptions Using the SPICE-R2F Instrument to Bridge Health-Care Policy and Education in France.

BACKGROUND: Public health policies in France and the USA promote health professionals' collaborative practices in accordance with World Health Organization recommendations emphasizing the need to promote interprofessional education and training. To optimize alignment of health-care policy and education, a scientific evidence-based approach is required. METHODS: A French translation (SPICE-R2F) of the Student Perceptions of Interprofessional Clinical Education-Revised instrument, version 2 (SPICE-R2) was generated. SPICE-R2F was then completed by a multicentric cohort of French health students, and confirmatory factor analysis was utilized to evaluate the validity and reliability of this instrument based on response patterns. RESULTS: Translation of SPICE-R2 was validated evaluating psychometric properties and conducting a confirmatory factor analysis (CFA). Adequate model fit was demonstrated using RMSEA (root mean square error of approximation) and CFI (comparative fit index) model fit criteria. Within each factor, however, low to moderate levels of reliability were observed between items. These observations diverge from other countries and highlight a potential French singularity. CONCLUSION: Our results suggest the need to improve interprofessional clinical practice education in France at early stages in the health-care curricula. The SPICE-R2F instrument may represent a valuable evidence-based tool to characterize perceptions of interprofessional education and training of health-care students and professionals in France.

Postural headache in a child with Marfan syndrome: case report and review of the literature.

The case of a 10-year-old female with Marfan syndrome and postural headache secondary to spontaneous intracranial hypotension is described. The patient was found to have multiple dural ectasias and a cerebrospinal fluid leak at the left cervicothoracic junction. Her presentation, diagnostic work-up, and management are reviewed, and the relevant literature is discussed. Spontaneous intracranial hypotension secondary to cerebrospinal fluid leaks from dural ectasia should be recognized as a potential complication in children with Marfan syndrome and other connective tissue diseases.