ABSTRACT
Determining the correct magnified pixel size of single-particle cryoEM micrographs is necessary to maximize resolution and enable accurate model building. Here we describe a simple and rapid procedure for determining the absolute magnification in an electron cryomicroscope to a precision of <0.5%. We show how to use the atomic lattice spacings of crystals of thin and readily available test specimens, such as gold, as an absolute reference to determine magnification for both room temperature and cryogenic imaging. We compare this method to other commonly used methods, and show that it provides comparable accuracy in spite of its simplicity. This magnification calibration method provides a definitive reference quantity for data analysis and processing, simplifies the combination of multiple datasets from different microscopes and detectors, and improves the accuracy with which the contrast transfer function of the microscope can be determined. We also provide an open source program, magCalEM, which can be used to accurately estimate the magnified pixel size of a cryoEM dataset ex post facto.
ABSTRACT
BACKGROUND: Acute Care for Elders (ACE) programs improve outcomes for older adults; however, little is known about whether impact varies with comorbidity severity. OBJECTIVE: To describe differences in hospital-level outcomes between ACE and routine care across various levels of comorbidity burden. DESIGN: Cross-sectional quality improvement study. SETTING: A 716-bed teaching hospital. PARTICIPANTS: Medical inpatients aged ≥70 years hospitalized between September 2014 and August 2017. INTERVENTION: ACE care, including interprofessional rounds, geriatric syndromes screening, and care protocols, in an environment prepared for elders MEASUREMENTS: Total cost, length of stay (LOS), and 30-day readmissions. We calculated median differences for cost and LOS between ACE and usual care and explored variations across the distribution of outcomes at the 25th, 50th, 75th and 90th percentiles. Results were also stratified across quartiles of the combined comorbidity score. RESULTS: A total of 1,429 ACE and 10,159 non-ACE patients were included in this study. The mean age was 81 years, 57% were female, and 81% were white. ACE patients had lower costs associated with care ranging from $171 at the 25th percentile to $3,687 at the 90th percentile, as well as lower LOS ranging from 0 days at the 25th percentile to 1.9 days at the 90th percentile. After stratifying by comorbidity score, the greatest differences in outcomes were among those with higher scores. There was no difference in 30-day readmission between the groups. CONCLUSION: The greatest reductions in cost and LOS were in patients with greater comorbidity scores. Risk stratification may help hospitals prioritize admissions to ACE units to maximize the impact of the more intensive intervention.
