ABSTRACT
Electron cryomicroscopy can, in principle, determine the structures of most biological molecules but is currently limited by access, specimen preparation difficulties, and cost. We describe a purpose-built instrument operating at 100 keV-including advances in electron optics, detection, and processing-that makes structure determination fast and simple at a fraction of current costs. The instrument attains its theoretical performance limits, allowing atomic resolution imaging of gold test specimens and biological molecular structure determination in hours. We demonstrate its capabilities by determining the structures of eleven different specimens, ranging in size from 140 kDa to 2 MDa, using a fraction of the data normally required. CryoEM with a microscope designed specifically for high-efficiency, on-the-spot imaging of biological molecules will expand structural biology to a wide range of previously intractable problems.
ABSTRACT
PURPOSE: Patent Ductus Arteriosus (PDA) ligation in premature infants is an urgent procedure performed by some but not all pediatric surgeons. Proficiency in PDA ligation is not a requirement of Canadian pediatric surgery training. Our purpose was to determine the outcomes of neonatal PDA ligation done by pediatric surgeons. METHODS: We performed a retrospective review of premature infants who underwent PDA ligation by pediatric surgeons in 3 Canadian centers from 2005 to 2009. Outcomes were compared to published controls. RESULTS: The review identified 98 patients with a mean corrected GA and weight at repair of 29 weeks and 1122 g, respectively. There were no intraoperative deaths. The 30-day and inhospital mortality rates were 1% and 5%. Mortality and morbidity were comparable to the published outcomes. CONCLUSIONS: This study documents that a significant number of preterm infant PDA ligations are safely done by pediatric surgeons. To meet the Canadian needs for this service by pediatric surgeons, proficiency in PDA ligation should be considered important in pediatric surgery training programs.
