Stanford type A dissections usually require surgery because they are associated with high morbidity and mortality. However, there are situations where medical management becomes the definitive treatment. We report the successful medical management of a 16-month chronic type A aortic dissection in a 56-year-old male patient with a past surgical history of ascending aortic aneurysm repair. The dissection is unique because it is distal to the graft and does not extend into the main aortic branches. A review of a patient's surgical history and nonenhanced imaging studies is essential when a type A dissection is discovered. Ascending aortic grafts may preclude the most serious complications of type A dissections.

Neuroendocrine neoplasms are most often found in the small intestine, rectum, appendix, and stomach. The colon, excluding the appendix and the cecum, is a rare location for these neoplasms and often gives rise to highly proliferative, poorly differentiated tumors with aggressive features and dismal prognosis. A 32-year-old male presents with a large cell neuroendocrine carcinoma arising from an unusual location, the descending colon. The patient's clinical and imaging characteristics resembles those seen in the much more common neoplasm, colonic adenocarcinoma. Computed tomography and In-111 octreotide scan are limited in diagnosing large cell neuroendocrine carcinoma. Pathologic correlation of a surgical specimen is required to make the correct diagnosis.

The adhesion of vapor deposited Au and Pt thin films onto poly(methyl methacrylate) (PMMA) substrates can be significantly enhanced by either spin‐casting or vapor‐exposure to hydrohalocarbon solvents prior to metal deposition. X‐ray photoelectron spectroscopy (XPS) and evolved gas analysis Fourier transform infrared spectroscopy detect residual halogenated solvent at the PMMA surface which chemically activates the surface. Density functional theory (DFT) calculations show that the solvent molecules form a Lewis acid‐base adduct with the ester oxygens in PMMA. DFT predicts that the deposited metal atom (M) inserts into the C–halogen (X) bond on either CHCl3 or CHBr3 to form a O–M–X interaction. This is consistent with M–X bonding observed in high resolution XPS. A model is proposed in which the bond energy of the C–X bond of the solvent must be weak enough so that it can be cleaved by the metal atom to form a M–X bond. A negative control of PMMA exposed to CHF3 is shown to have no effect on Au or Pt adhesion since the bond dissociation energy of the C–F bond is stronger than the C–Cl and C–Br bond energy compared to the metal halide bond energies.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Alan K. Mo, Thomas C. DeVore, Brian H. Augustine, Vezekile P. Zungu, Laura L. Lee, Wm. Christopher Hughes; Improving the adhesion of Au thin films onto poly(methyl methacrylate) substrates using spun-cast organic solvents. J. Vac. Sci. Technol. A 1 May 2011; 29 (3): 030601. https://doi.org/10.1116/1.3562167 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAVS: Science & Technology of Materials Interfaces and ProcessingJournal of Vacuum Science & Technology A Search Advanced Search |Citation Search