Serial femtosecond crystallography requires reliable and efficient delivery of fresh crystals across the beam of an X-ray free-electron laser over the course of an experiment. We introduce a double-flow focusing nozzle to meet this challenge, with significantly reduced sample consumption, while improving jet stability over previous generations of nozzles. We demonstrate its use to determine the first room-temperature structure of RNA polymerase II at high resolution, revealing new structural details. Moreover, the double flow-focusing nozzles were successfully tested with three other protein samples and the first room temperature structure of an extradiol ring-cleaving dioxygenase was solved by utilizing the improved operation and characteristics of these devices.

X-ray free-electron lasers provide novel opportunities to conduct single particle analysis on nanoscale particles. Coherent diffractive imaging experiments were performed at the Linac Coherent Light Source (LCLS), SLAC National Laboratory, exposing single inorganic core-shell nanoparticles to femtosecond hard-X-ray pulses. Each facetted nanoparticle consisted of a crystalline gold core and a differently shaped palladium shell. Scattered intensities were observed up to about 7 nm resolution. Analysis of the scattering patterns revealed the size distribution of the samples, which is consistent with that obtained from direct real-space imaging by electron microscopy. Scattering patterns resulting from single particles were selected and compiled into a dataset which can be valuable for algorithm developments in single particle scattering research.

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here.

As Baby Boomers age, the number of older homeless patients facing end of life is increasing. Homeless individuals die of the same diseases as their domiciled counterparts, but they have distinct barriers to equitable end-of-life care, such as lack of regular medical care, a higher likelihood of comorbid serious mental illness and substance abuse, alienation from potential healthcare proxies, and specific fears related to dying. Completion of an advance directive (AD) would address many of these barriers, as well as national goals of reducing medical costs associated with end of life care. A review of the literature indicates that homeless individuals, once educated on the purpose and significance of ADs, complete them at a higher rate than non-homeless people. Further, racial and ethnic disparities in document completion are minimized with educational interventions about an AD’s purpose.

King’s Theory of Goal Attainment provides the theoretical basis for the application of such an intervention in the setting of a medical respite center and a day resource center that both serve the homeless. Thirty-seven clients of the two sites and 14 staff members were administered a pre-and post-test measuring attitudes and knowledge relating to ADs on a Likert scale, resulting in an increase in knowledge about one of the two documents that traditionally comprise an AD, while not significantly affecting attitudes. Implications for practice include an inexpensive intervention that does not require a medically trained individual to deliver, enabling a broad application to a variety of settings with the goal of empowering a traditionally disenfranchised population to make health decisions related to the most vulnerable of life passages.