X-Ray Imaging in the Simulated Microgravity Environment of Parabolic Flight.

INTRODUCTION: The advancement of human spaceflight has made urgent the need to develop medical imaging technology to ensure a high level of in-flight care. To date, only ultrasound has been used in spaceflight. Radiography has multiple advantages over ultrasound, including lower operator dependence, more rapid acquisition, typically higher spatial resolution, and characterization of tissue with acoustic impedance precluding ultrasound. This proof-of-concept work demonstrates for the first time the feasibility of performing human radiographs in microgravity.METHODS: Radiographs of a phantom and human subject's hand, knee, chest, cervical spine, and pelvis were obtained aboard a parabolic flight in microgravity and simulated lunar gravity with various subject and operator positions. Control radiographs were acquired with the same system on the ground. These radiographs were performed with a Food and Drug Administration-approved ultra-portable, wireless, battery-powered, digital x-ray system.RESULTS: The radiographs of the phantom acquired in reduced gravity were qualitatively and quantitatively compared to the ground controls and found to exhibit similar diagnostic adequacy. There was no statistically significant difference in contrast resolution or spatial resolution with a spatial resolution across all imaging environments up to the Nyquist frequency of 3.6 line-pairs/mm and an average contrast-to-noise ratio of 2.44.DISCUSSION: As mass, power, and volume limitations lessen over the coming decades and the miniaturization of imaging equipment continues, in-flight implementation of nonsonographic modalities will become practical. Given the demonstrated ease of use and satisfactory image quality, portable radiography is ready to be the new frontier of space medical imaging.Lerner D, Pohlen M, Wang A, Walter J, Cairnie M, Gifford S. X-ray imaging in the simulated microgravity environment of parabolic flight. Aerosp Med Hum Perform. 2023; 94(10):786-791.

A scoping review of de-implementation frameworks and models.

BACKGROUND: Reduction or elimination of inappropriate, ineffective, or potentially harmful healthcare services and public health programs can help to ensure limited resources are used effectively. Frameworks and models (FM) are valuable tools in conceptualizing and guiding the study of de-implementation. This scoping review sought to identify and characterize FM that can be used to study de-implementation as a phenomenon and identify gaps in the literature to inform future model development and application for research. METHODS: We searched nine databases and eleven journals from a broad array of disciplines (e.g., healthcare, public health, public policy) for de-implementation studies published between 1990 and June 2020. Two raters independently screened titles and abstracts, and then a pair of raters screened all full text records. We extracted information related to setting, discipline, study design, methodology, and FM characteristics from included studies. RESULTS: The final search yielded 1860 records, from which we screened 126 full text records. We extracted data from 27 articles containing 27 unique FM. Most FM (n = 21) were applicable to two or more levels of the Socio-Ecological Framework, and most commonly assessed constructs were at the organization level (n = 18). Most FM (n = 18) depicted a linear relationship between constructs, few depicted a more complex structure, such as a nested or cyclical relationship. Thirteen studies applied FM in empirical investigations of de-implementation, while 14 articles were commentary or review papers that included FM. CONCLUSION: De-implementation is a process studied in a broad array of disciplines, yet implementation science has thus far been limited in the integration of learnings from other fields. This review offers an overview of visual representations of FM that implementation researchers and practitioners can use to inform their work. Additional work is needed to test and refine existing FM and to determine the extent to which FM developed in one setting or for a particular topic can be applied to other contexts. Given the extensive availability of FM in implementation science, we suggest researchers build from existing FM rather than recreating novel FM. REGISTRATION: Not registered.

Kidney transplantation, bioengineering and regeneration: an originally immunology-based discipline destined to transition towards ad hoc organ manufacturing and repair.

Kidney transplantation (KT), as a modality of renal replacement therapy (RRT), has been shown to be both economically and functionally superior to dialysis for the treatment of end-stage renal disease (ESRD). Progress in KT is limited by two major barriers: a) a chronic and burgeoning shortage of transplantable organs and b) the need for chronic immunosuppression following transplantation. Although ground-breaking advances in transplant immunology have improved patient survival and graft durability, a new pathway of innovation is needed in order to overcome current obstacles. Regenerative medicine (RM) holds the potential to shift the paradigm in RRT, through organ bioengineering. Manufactured organs represent a potentially inexhaustible source of transplantable grafts that would bypass the need for immunosuppressive drugs by using autologous cells to repopulate extracellular matrix (ECM) scaffolds. This overview discusses the current status of renal transplantation while reviewing the most promising innovations in RM therapy as applied to RRT.