2 resultados para ISM: supernova remnants

em DRUM (Digital Repository at the University of Maryland)


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In the summers of 1998 and 1999, the Archaeology in Annapolis project carried out archaeological investigation at the eighteenth century Dr. Upton Scott House site (18AP18)located at 4 Shipwright Street in the historic district of Annapolis, Anne Arundel County, Maryland. The Upton Scott House is significant as one of only a few Georgian houses with remnants of its original plantation-inspired landscape still visible (Graham 1998:147). Investigation was completed in agreement with the owners of the historic property, Mr. and Mrs. Paul Christian, who were interested in determining the condition and arrangement of Dr. Upton Scott’s well-documented pleasure gardens. Betty Cosans’ 1972 Archaeological Feasibility Report, the first real archaeological study of the Upton Scott House site, guided the research design and recovery efforts. Cosans determined that testing and survey in the back and side yards of the Scott property would yield important information on the use and history of the property, including that of Scott’s famous gardens. Excavation units and trenches were placed within three separate areas of backyard activity on the site which included Area One: extant brick stables in the southwest of the property; Area Two: the brick foundations of a small outbuilding located in the northwest area of the site; and Area Three: the area of Scott’s formal gardens. The research design included an interest in recovering evidence of African-American spiritual practice and domestic life at the site. Also of significant importance was an analysis of Scott’s garden beds, concerning the order and layout. Also sought was an understanding of the change in perception and use of the backyard by the various owners of the property.

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Intercellular adhesion molecule 1 (ICAM-1) is a transmembrane protein found on the surface of vascular endothelial cells (ECs). Its expression is upregulated at inflammatory sites, allowing for targeted delivery of therapeutics using ICAM-1-binding drug carriers. Engagement of multiple copies of ICAM-1 by these drug carriers induces cell adhesion molecule (CAM)-mediated endocytosis, which results in trafficking of carriers to lysosomes and across ECs. Knowledge about the regulation behind CAM-mediated endocytosis can help improve drug delivery, but questions remain about these regulatory mechanisms. Furthermore, little is known about the natural function of this endocytic pathway. To address these gaps in knowledge, we focused on two natural binding partners of ICAM-1 that potentially elicit CAM-mediated endocytosis: leukocytes (which bind ICAM-1 via β2 integrins) and fibrin polymers (a main component of blood clots which binds ICAM-1 via the γ3 sequence). First, inspired by properties of these natural binding partners, we varied the size and targeting moiety of model drug carriers to determine how these parameters affect CAM-mediated endocytosis. Increasing ICAM-1-targeted carrier size slowed carrier uptake kinetics, reduced carrier trafficking to lysosomes, and increased carrier transport across ECs. Changing targeting moieties from antibodies to peptides decreased particle binding and uptake, lowered trafficking to lysosomes, and increased transport across ECs. Second, using cell culture models of leukocyte/EC interactions, inhibiting regulatory elements of the CAM-mediated pathway disrupted leukocyte sampling, a process crucial to leukocyte crossing of endothelial layers (transmigration). This inhibition also decreased leukocyte transmigration across ECs, specifically through the transcellular route, which occurs through a single EC without disassembly of cell-cell junctions. Third, fibrin meshes, which mimic blood clot fragments/remnants, bound to ECs at ICAM-1-enriched sites and were internalized by the endothelium. Inhibiting the CAM-mediated pathway disrupted this uptake. Following endocytosis, fibrin meshes trafficked to lysosomes where they were degraded. In mouse models, CAM-mediated endocytosis of fibrin meshes appeared to remove fibrin remnants at the endothelial surface, preventing re-initiation of the coagulation cascade. Overall, these results support a link between CAM-mediated endocytosis and leukocyte transmigration as well as uptake of fibrin materials by ECs. Furthermore, these results will guide the future design of ICAM-1-targeted carrier-assisted therapies.