A Methodology for Successful University Graduate CubeSat Programs

The University of Colorado Smead Department of Aerospace Engineering has over a decade of success in designing, building, and operating student led CubeSat missions. The experience and lessons learned from building and operating the CSSWE, MinXSS-1, MinXSS-2, and QB50-Challenger missions have helped grow a knowledge base on the most effective and efficient ways to manage some of the “tall poles” when it comes to student run CubeSat missions. Among these “tall poles” we have seen student turnover, software, and documentation become some of the hardest to knock-down and we present our strategies for doing so. We use the MAXWELL mission (expected to launch in 2021) as a road-map to detail the methodology we have built over the last decade to ensure the greatest chance of mission success

Influence of pre-operative diagnosis and frozen section on operative management of pancreatic cystic lesions

Background. Frozen section analysis of cyst wall has been advocated as standard of care prior to surgical drainage of pancreatic pseudocysts. Recent studies have indicated that frozen section may be unreliable. Our aim was to investigate the role and accuracy of frozen section analysis of the cyst wall in the operative management of pancreatic cystic lesions. Methods. A retrospective review was performed of 44 patients who underwent operation for a cystic lesion of the pancreas. Results. Of the 25 patients with a diagnosis of pseudocyst, 9 patients had frozen section intra-operatively. Eight frozen sections demonstrated pseudocyst, and correlated with final pathology. One frozen section demonstrated a true cyst. Twenty-three patients had a final diagnosis of pseudocyst. Nineteen patients had a diagnosis of cystic neoplasm, and six patients had frozen sections. Three frozen sections were consistent with cystic neoplasm and correlated with final pathology. Three frozen sections demonstrated characteristics of pseudocyst, two correlated with final pathology, and one showed cystic neoplasm on final pathology. Conclusion. Routine use of frozen section may not be necessary; however, frozen section is useful when the intra-operative appearance does not correlate with pre-operative diagnosis

Amino terminus of cardiac myosin binding protein-C regulates cardiac contractility

Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) regulates cardiac contraction through modulation of actomyosin interactions mediated by the protein's amino terminal (N′)-region (C0-C2 domains, 358 amino acids). On the other hand, dephosphorylation of cMyBP-C during myocardial injury results in cleavage of the 271 amino acid C0-C1f region and subsequent contractile dysfunction. Yet, our current understanding of amino terminus region of cMyBP-C in the context of regulating thin and thick filament interactions is limited. A novel cardiac-specific transgenic mouse model expressing cMyBP-C, but lacking its C0-C1f region (cMyBP-C∆C0-C1f), displayed dilated cardiomyopathy, underscoring the importance of the N′-region in cMyBP-C. Further exploring the molecular basis for this cardiomyopathy, in vitro studies revealed increased interfilament lattice spacing and rate of tension redevelopment, as well as faster actin-filament sliding velocity within the C-zone of the transgenic sarcomere. Moreover, phosphorylation of the unablated phosphoregulatory sites was increased, likely contributing to normal sarcomere morphology and myoarchitecture. These results led us to hypothesize that restoration of the N′-region of cMyBP-C would return actomyosin interaction to its steady state. Accordingly, we administered recombinant C0-C2 (rC0-C2) to permeabilized cardiomyocytes from transgenic, cMyBP-C null, and human heart failure biopsies, and we found that normal regulation of actomyosin interaction and contractility was restored. Overall, these data provide a unique picture of selective perturbations of the cardiac sarcomere that either lead to injury or adaptation to injury in the myocardium