ABSTRACT
Artifact metrics is an information security technology that uses the intrinsic characteristics of a physical object for authentication and clone resistance. Here, we demonstrate nano-artifact metrics based on silicon nanostructures formed via an array of resist pillars that randomly collapse when exposed to electron-beam lithography. The proposed technique uses conventional and scalable lithography processes, and because of the random collapse of resist, the resultant structure has extremely fine-scale morphology with a minimum dimension below 10â nm, which is less than the resolution of current lithography capabilities. By evaluating false match, false non-match and clone-resistance rates, we clarify that the nanostructured patterns based on resist collapse satisfy the requirements for high-performance security applications.
ABSTRACT
We present two cases of severely calcified thoracoabdominal aortic aneurysm treated by means of endografting with a retrograde aortomesenteric bifurcated bypass graft reconstructing the celiac axis and superior mesenteric artery. To avoid spinal ischemia, we monitored evoked spinal cord potential and performed an occlusion test of the intercostal arteries using a retrievable stentgraft. No change in evoked spinal cord potential was noted, and no endoleaks or complications, including paraplegia, were observed. This procedure is a feasible and less-invasive treatment for severely calcified thoracoabdominal aortic aneurysms.
